#30376

Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM batteries and a 4 channel DualPro charger.? I've had ten great summers using this configuration on some inland lakes in Ohio. Last summer, I started noticing the battery capacity wasn't what it was when the batteries were new.? The Torqeedo would shut down due to "depleted batteries", but I was always able to turn it off and then back on where upon I could return home at a slower pace. That is one of the things I like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more usable range.

As an engineer, I like using new technologies so I lean toward the LiFePo4's.? However, many of the posters I follow on this forum bought them directly from Chinese suppliers.? With all the COVID 19 disruptions to business and our government threatening to raise tariffs, I worry about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30377

Is that 24v or 48v?

Can buy surpluses Tesla ,?leaf or other?packs too

Show quoted text

On Monday, April 27, 2020, 07:43, greenpjs04 <forums@...> wrote:

Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to
electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM
batteries and a 4 channel DualPro charger.? I've had ten great summers
using this configuration on some inland lakes in Ohio. Last summer, I
started noticing the battery capacity wasn't what it was when the
batteries were new.? The Torqeedo would shut down due to "depleted
batteries", but I was always able to turn it off and then back on where
upon I could return home at a slower pace. That is one of the things I
like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain
about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more
usable range.

As an engineer, I like using new technologies so I lean toward the
LiFePo4's.? However, many of the posters I follow on this forum bought
them directly from Chinese suppliers.? With all the COVID 19 disruptions
to business and our government threatening to raise tariffs, I worry
about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any
recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30378

The Torqeedo Cruise 4 is a 48V system.

I also have one on a small wooden boat, that originally used a gas outboard.

I'm going to attempt running it on a 48V electric bike battery - but the ebike battery only has a 20Ah rating - so this will only be for proof of concept, and clearly won't power the motor for very long, and the motor will have to ONLY be run at very low power.

Are any of the surplus Tesla or Leaf batteries available in 48V banks, or can they be easily configured for 48V?

The ebike batteries are easy to use, and reasonably priced.? Just not sure if they can be combined in parallel??

The ebike batteries typically have internal BMS systems of unknown type.? I'm assuming they should NOT be charged in parallel, and I really don't know how reasonable it would be to connect them in parallel for running.

Thoughts?

John

On Monday, April 27, 2020, 10:03:53 AM CDT, sw via groups.io <v1opps@...> wrote:

Is that 24v or 48v?

Can buy surpluses Tesla ,?leaf or other?packs too

Show quoted text

On Monday, April 27, 2020, 07:43, greenpjs04 <forums@...> wrote:

Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to
electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM
batteries and a 4 channel DualPro charger.? I've had ten great summers
using this configuration on some inland lakes in Ohio. Last summer, I
started noticing the battery capacity wasn't what it was when the
batteries were new.? The Torqeedo would shut down due to "depleted
batteries", but I was always able to turn it off and then back on where
upon I could return home at a slower pace. That is one of the things I
like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain
about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more
usable range.

As an engineer, I like using new technologies so I lean toward the
LiFePo4's.? However, many of the posters I follow on this forum bought
them directly from Chinese suppliers.? With all the COVID 19 disruptions
to business and our government threatening to raise tariffs, I worry
about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any
recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30379

Hello Pat,? I did the upgrade last year. I went from 4? 12v 220 ah agm to? ?lifepo4? ? I put together 4 battery boxes with? 3.2v 90ah cylinder cells. 4P4S for each box. Then in series for 48v system. You will need a bms and a different? charger? This is a cool upgrade and not too difficult.. I am able to monitor the batteries in charge and discharge mode at any given time with my I phone.? I have great continuous run time and overnite charging with? my dock power. I can suggest a couple sources depending on east or west coast usa.;? I hope this helps.? thank you? best regards Larry Schmitz

?Terminalift LLC

9444 Mission Park Place

Santee, CA 92071

Ph: (619) 562-0355

F: (619) 562-2060

On Monday, April 27, 2020, 08:03:54 AM PDT, sw via groups.io <v1opps@...> wrote:

Is that 24v or 48v?

Can buy surpluses Tesla ,?leaf or other?packs too

Show quoted text

On Monday, April 27, 2020, 07:43, greenpjs04 <forums@...> wrote:

Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to
electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM
batteries and a 4 channel DualPro charger.? I've had ten great summers
using this configuration on some inland lakes in Ohio. Last summer, I
started noticing the battery capacity wasn't what it was when the
batteries were new.? The Torqeedo would shut down due to "depleted
batteries", but I was always able to turn it off and then back on where
upon I could return home at a slower pace. That is one of the things I
like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain
about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more
usable range.

As an engineer, I like using new technologies so I lean toward the
LiFePo4's.? However, many of the posters I follow on this forum bought
them directly from Chinese suppliers.? With all the COVID 19 disruptions
to business and our government threatening to raise tariffs, I worry
about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any
recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30380

Can build batteries cell by cell to what u want like some lg batteries

Even old laptop batteries

I believe the Tesla packs are 24v

Can run them in series

Not sure if the bms has been hacked for them or not

Leaf batteries are about 8v? A?battery

Some say u can Parallel?cells so you need smaller bms just make sure each cell about same voltage as the rest

Technically I believe once u parallel?they will self equalize?

I have been using 32s ant bms that has a Bluetooth bms so you monitor it all in a cell phone

Can check the web or eBay for Tesla prices off too my head $1000 for 24v ??? ?But they last a long time

Show quoted text

On Monday, April 27, 2020, 08:17, john via groups.io <oak_box@...> wrote:

The Torqeedo Cruise 4 is a 48V system.

I also have one on a small wooden boat, that originally used a gas outboard.
I'm going to attempt running it on a 48V electric bike battery - but the ebike battery only has a 20Ah rating - so this will only be for proof of concept, and clearly won't power the motor for very long, and the motor will have to ONLY be run at very low power.

Are any of the surplus Tesla or Leaf batteries available in 48V banks, or can they be easily configured for 48V?

The ebike batteries are easy to use, and reasonably priced.? Just not sure if they can be combined in parallel??
The ebike batteries typically have internal BMS systems of unknown type.? I'm assuming they should NOT be charged in parallel, and I really don't know how reasonable it would be to connect them in parallel for running.

Thoughts?

John

On Monday, April 27, 2020, 10:03:53 AM CDT, sw via groups.io <v1opps@...> wrote:

Is that 24v or 48v?
Can buy surpluses Tesla ,?leaf or other?packs too

On Monday, April 27, 2020, 07:43, greenpjs04 <forums@...> wrote:
Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to
electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM
batteries and a 4 channel DualPro charger.? I've had ten great summers
using this configuration on some inland lakes in Ohio. Last summer, I
started noticing the battery capacity wasn't what it was when the
batteries were new.? The Torqeedo would shut down due to "depleted
batteries", but I was always able to turn it off and then back on where
upon I could return home at a slower pace. That is one of the things I
like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain
about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more
usable range.

As an engineer, I like using new technologies so I lean toward the
LiFePo4's.? However, many of the posters I follow on this forum bought
them directly from Chinese suppliers.? With all the COVID 19 disruptions
to business and our government threatening to raise tariffs, I worry
about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any
recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30381

Pat,
Battleborne Lifepo4 are made in the US. I just got some batteries from another company in China that shipped in late January, so they were still shipping at that time. About $3k for 13 kwh worth with a BMS. The Tesla option is quite a bit cheaper but since they are pure lithium I don't know if I would want them on a boat. I think the Leaf is NIMH. 
Jerry

Show quoted text

On April 27, 2020, at 9:43 AM, greenpjs04 <forums@...> wrote:

Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to 
electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM 
batteries and a 4 channel DualPro charger.? I've had ten great summers 
using this configuration on some inland lakes in Ohio. Last summer, I 
started noticing the battery capacity wasn't what it was when the 
batteries were new.? The Torqeedo would shut down due to "depleted 
batteries", but I was always able to turn it off and then back on where 
upon I could return home at a slower pace. That is one of the things I 
like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain 
about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more 
usable range.

As an engineer, I like using new technologies so I lean toward the 
LiFePo4's.? However, many of the posters I follow on this forum bought 
them directly from Chinese suppliers.? With all the COVID 19 disruptions 
to business and our government threatening to raise tariffs, I worry 
about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any 
recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30382

They have buck boost cc cv chargers?made for solar but can use off a computer power supply too?

they about $30-40 on eBay?

Bms on eBay too

They adjustable max 60-130v

But u can dial in any voltage u want?

Show quoted text

On Monday, April 27, 2020, 09:12, shredderf16 <Shredderf16@...> wrote:

Pat,
Battleborne Lifepo4 are made in the US. I just got some batteries from another company in China that shipped in late January, so they were still shipping at that time. About $3k for 13 kwh worth with a BMS. The Tesla option is quite a bit cheaper but since they are pure lithium I don't know if I would want them on a boat. I think the Leaf is NIMH.
Jerry

On April 27, 2020, at 9:43 AM, greenpjs04 <forums@...> wrote:

Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to
electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM
batteries and a 4 channel DualPro charger.? I've had ten great summers
using this configuration on some inland lakes in Ohio. Last summer, I
started noticing the battery capacity wasn't what it was when the
batteries were new.? The Torqeedo would shut down due to "depleted
batteries", but I was always able to turn it off and then back on where
upon I could return home at a slower pace. That is one of the things I
like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain
about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more
usable range.

As an engineer, I like using new technologies so I lean toward the
LiFePo4's.? However, many of the posters I follow on this forum bought
them directly from Chinese suppliers.? With all the COVID 19 disruptions
to business and our government threatening to raise tariffs, I worry
about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any
recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30383

maybe surplus? volt or bolt batteries then??

On Monday, April 27, 2020, 9:12:03 AM PDT, shredderf16 <shredderf16@...> wrote:

Pat,

Battleborne Lifepo4 are made in the US. I just got some batteries from another company in China that shipped in late January, so they were still shipping at that time. About $3k for 13 kwh worth with a BMS. The Tesla option is quite a bit cheaper but since they are pure lithium I don't know if I would want them on a boat. I think the Leaf is NIMH.

Jerry

Show quoted text

On April 27, 2020, at 9:43 AM, greenpjs04 <forums@...> wrote:

Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to

electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM

batteries and a 4 channel DualPro charger.? I've had ten great summers

using this configuration on some inland lakes in Ohio. Last summer, I

started noticing the battery capacity wasn't what it was when the

batteries were new.? The Torqeedo would shut down due to "depleted

batteries", but I was always able to turn it off and then back on where

upon I could return home at a slower pace. That is one of the things I

like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain

about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more

usable range.

As an engineer, I like using new technologies so I lean toward the

LiFePo4's.? However, many of the posters I follow on this forum bought

them directly from Chinese suppliers.? With all the COVID 19 disruptions

to business and our government threatening to raise tariffs, I worry

about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any

recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30384

I have 10KW of LifePo4 batteries on order from China and are due to land in Toronto first week of May. My cost so far was $2600 Canadian or $1900 US. I have not cleared customs yet so not sure what the duty and taxes will be.
My question is why do you need a different charger as mentioned below? The LifePo4 cells can be charged to 3.65 volts max so is there another factor I am not thinking of?

Phil

On Monday, April 27, 2020, 11:49:32 a.m. EDT, L Schmitz via groups.io <terminalift@...> wrote:

Hello Pat,? I did the upgrade last year. I went from 4? 12v 220 ah agm to? ?lifepo4? ? I put together 4 battery boxes with? 3.2v 90ah cylinder cells. 4P4S for each box. Then in series for 48v system. You will need a bms and a different? charger? This is a cool upgrade and not too difficult.. I am able to monitor the batteries in charge and discharge mode at any given time with my I phone.? I have great continuous run time and overnite charging with? my dock power. I can suggest a couple sources depending on east or west coast usa.;? I hope this helps.? thank you? best regards Larry Schmitz

?Terminalift LLC

9444 Mission Park Place

Santee, CA 92071

Ph: (619) 562-0355

F: (619) 562-2060

On Monday, April 27, 2020, 08:03:54 AM PDT, sw via groups.io <v1opps@...> wrote:

Is that 24v or 48v?

Can buy surpluses Tesla ,?leaf or other?packs too

Show quoted text

On Monday, April 27, 2020, 07:43, greenpjs04 <forums@...> wrote:

Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to
electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM
batteries and a 4 channel DualPro charger.? I've had ten great summers
using this configuration on some inland lakes in Ohio. Last summer, I
started noticing the battery capacity wasn't what it was when the
batteries were new.? The Torqeedo would shut down due to "depleted
batteries", but I was always able to turn it off and then back on where
upon I could return home at a slower pace. That is one of the things I
like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain
about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more
usable range.

As an engineer, I like using new technologies so I lean toward the
LiFePo4's.? However, many of the posters I follow on this forum bought
them directly from Chinese suppliers.? With all the COVID 19 disruptions
to business and our government threatening to raise tariffs, I worry
about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any
recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30386

It was explained to me by a local battery authority that Charging method changes. Constant voltage is agm charge method.? ?Constant current -constant voltage is lifepo4 charge method. It can charge with either method but gains cycle life with the cc-cv method.? I hope this helps? ?thank? you? ?kind regards Larry Schmitz

?Terminalift LLC

9444 Mission Park Place

Santee, CA 92071

Ph: (619) 562-0355

F: (619) 562-2060

On Monday, April 27, 2020, 09:50:23 AM PDT, Phil Boyer via groups.io <philaboyer@...> wrote:

I have 10KW of LifePo4 batteries on order from China and are due to land in Toronto first week of May. My cost so far was $2600 Canadian or $1900 US. I have not cleared customs yet so not sure what the duty and taxes will be.
My question is why do you need a different charger as mentioned below? The LifePo4 cells can be charged to 3.65 volts max so is there another factor I am not thinking of?

Phil

On Monday, April 27, 2020, 11:49:32 a.m. EDT, L Schmitz via groups.io <terminalift@...> wrote:

Hello Pat,? I did the upgrade last year. I went from 4? 12v 220 ah agm to? ?lifepo4? ? I put together 4 battery boxes with? 3.2v 90ah cylinder cells. 4P4S for each box. Then in series for 48v system. You will need a bms and a different? charger? This is a cool upgrade and not too difficult.. I am able to monitor the batteries in charge and discharge mode at any given time with my I phone.? I have great continuous run time and overnite charging with? my dock power. I can suggest a couple sources depending on east or west coast usa.;? I hope this helps.? thank you? best regards Larry Schmitz

?Terminalift LLC

9444 Mission Park Place

Santee, CA 92071

Ph: (619) 562-0355

F: (619) 562-2060

On Monday, April 27, 2020, 08:03:54 AM PDT, sw via groups.io <v1opps@...> wrote:

Is that 24v or 48v?

Can buy surpluses Tesla ,?leaf or other?packs too

Show quoted text

On Monday, April 27, 2020, 07:43, greenpjs04 <forums@...> wrote:

Hello everyone,

Over 10 years ago, you guys helped me to convert my 24' pontoon to
electric.? I ended up with a Torqeedo Cruise 4, four group 31 AGM
batteries and a 4 channel DualPro charger.? I've had ten great summers
using this configuration on some inland lakes in Ohio. Last summer, I
started noticing the battery capacity wasn't what it was when the
batteries were new.? The Torqeedo would shut down due to "depleted
batteries", but I was always able to turn it off and then back on where
upon I could return home at a slower pace. That is one of the things I
like about electric vs gasoline.? I have never been stranded.

Anyway, I suppose it is time to replace the batteries.? I can't complain
about getting 10 years out of them.? As I see it, I have two options:

1. Buy another set of AGMs - a little under $1000

2. Buy LiFePo4's - at least double the cost, but less weight and more
usable range.

As an engineer, I like using new technologies so I lean toward the
LiFePo4's.? However, many of the posters I follow on this forum bought
them directly from Chinese suppliers.? With all the COVID 19 disruptions
to business and our government threatening to raise tariffs, I worry
about placing an order that never gets filled.

I would appreciate any opinions on which way to go and any
recommendations for low risk suppliers for batteries.

Thanks,

Pat

#30387

On 28/4/20 12:43 am, greenpjs04 wrote:
. The Torqeedo would shut down due to "depleted batteries", but I was always able to turn it off and then back on where upon I could return home at a slower pace.

Anyway, I suppose it is time to replace the batteries.? I can't complain about getting 10 years out of them.? As I see it, I have two options:
I'm in the same position, after 10 years my Trojan flooded T145s are showing 'voltage depression' rather rapidly. They will have to be replaced before next season.

I'm sort of in the sane position, replace the Trojans with the same or switch to one of the modern Li chemistries.

#30388

look at the used valence batteries, thunderstruck and others have them. they are a super value plus the bms is easy?to use.?

#30389

I still use flooded lead acid --- on a 1920 Milburn electric car I own.
Its Interstate golf cart (T105 style) batteries are pushing 9 years now (time flies).  Last year I wanted to drive the ol' car to work (16mi one way) and back.  But I didn't have much confidence in the batteries.  Over a weekend, I charged the batteries, first with golf-cart 25amp chargers (one 48v, the other 36v---pack is 84v) but the charging stopped without too many amp-hours put in.  So I switched to my nom. 106v current-limited power supply, which didn't add a whole lot either.  Checking the cells, I found that the electrolyte levels weren't very good at all.  What could I do?  Well, get my 50amp current limited 12v charger and put it across each 6v battery, that's what!  Actually, that charger had recently had something go out on it so it was not voltage-limiting at 14-15v and was instead putting out maybe 20v.  So after rebuilding the charger's cables to handle the 50amps, I turned on this charger and clipped it across each pair or triplet of series batteries, pumping high current into them until I just started to smell outgassing, or the "burping" in the cells was getting too lively or contacts getting warm or the volts per cell changes suggested it's time to disconnect.  I repeated for each of the 7 pairs of batteries.  The result: After doing this, driving the car around, then repeating this treatment, the electrolyte levels of every cell returned to the GOOD range.  And the ordinary golf cart chargers then did their job better after.  Ultimately, there was plenty of juice to get me to the car show at work, where the car one Best In Show :-).  I drove it to work another day or two later also.

Bottom line: Don't ignore the risks of sulfation of PbA batteries that are not cycled with any regularity.  And to recover these, you need to do more than put a standard charger on them since the voltage-limitation will not allow the clearing of the sulfation.  Some badly sulfated batteries appear completely dead unless hit with 50-150vDC (current limited of course) to get the current to start flowing.  And even then, if you monitor the voltage, you'll find that the voltage actually "drops" as the battery charges.
Be very mindful of temperature and outgassing, particularly if you are trying to bring capacity back to a sealed- or AGM battery.  Any sulfur released is not coming back---and you need that sulfuric acid.

-MT

Show quoted text

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Matthew Geier
Sent: Monday, April 27, 2020 1:47 PM
To: [email protected]
Subject: Re: [electricboats] AGM or LiFePo4

On 28/4/20 12:43 am, greenpjs04 wrote:
. The Torqeedo would shut down due to "depleted batteries", but I was always able to turn it off and then back on where upon I could return home at a slower pace.

Anyway, I suppose it is time to replace the batteries.  I can't complain about getting 10 years out of them.  As I see it, I have two options:
I'm in the same position, after 10 years my Trojan flooded T145s are showing 'voltage depression' rather rapidly. They will have to be replaced before next season.

I'm sort of in the sane position, replace the Trojans with the same or switch to one of the modern Li chemistries.

Bill Farina

#30390

开云体育

Valence 12.8V are going for $350ea at Thunderstruck. The BMS is $250. For the batteries, this seems high.

On 4/27/2020 2:27 PM, Brian wrote:

Show quoted text

look at the used valence batteries, thunderstruck and others have them. they are a super value plus the bms is easy?to use.?

#30391

Wow!? Thank you for all the responses.? I will investigate all your suggestions further.? One topic that came up but has me confused is the BMS needed for LiFePo4 batteries.? From past research, I know that some cells offered for sale are just that - cells without any BMS.? To use those, I would have to add a BMS designed for LiFePo4 chemistry.? DualPro's website says their chargers "can" be programmed for LiFePo4 but I doubt that applies to my 10 year old AGM charger.

So, moving on to the LiFePo4 battery packs with built in BMS's, how does one charge those?? I found very little detail mentioned. Just things like "Includes BMS!" and similar claims.? Can any charger with a voltage above the battery voltage be used to charge these batteries?? In other words, does the internal BMS fully protect the batteries by handling charge rate and monitoring state of charge to avoid over-charging?

Pat

#30392

I've been working on a team in Germany developing some lithium?batteries and BMS for outdoor and marine usage. There are huge differences in BMS quality and feature sets but what almost every Lithium BMS would do for you is to cut off charging to the batteries when they reach a??pre determined?100% charge level to prevent you from overcharging the?pack. For LiFePO4 this will be about 3.65v for a single cell or for a 4 Series 12.8V pack that would be 14.6V.? ??

I don't have so much experience with AGM but your AGM charger is probably putting out 14.4 - 14.8V which is so close to the 14.6V that it would not be a big problem for you I would think,?not dangerous in any case.? Your BMS will shut off the charge to your batteries so that they don't go above that 14.6 level once it has been reached so?there is no risk of over charging the battery.? ?Your AGM charger will probably try to taper the charge according to a profile set for AGM so it would be sub optimal for LiFePO4.??

Show quoted text

On Tue, Apr 28, 2020 at 12:31 PM greenpjs04 <forums@...> wrote:

Wow!? Thank you for all the responses.? I will investigate all your
suggestions further.? One topic that came up but has me confused is the
BMS needed for LiFePo4 batteries.? From past research, I know that some
cells offered for sale are just that - cells without any BMS.? To use
those, I would have to add a BMS designed for LiFePo4 chemistry.?
DualPro's website says their chargers "can" be programmed for LiFePo4
but I doubt that applies to my 10 year old AGM charger.

So, moving on to the LiFePo4 battery packs with built in BMS's, how does
one charge those?? I found very little detail mentioned. Just things
like "Includes BMS!" and similar claims.? Can any charger with a voltage
above the battery voltage be used to charge these batteries?? In other
words, does the internal BMS fully protect the batteries by handling
charge rate and monitoring state of charge to avoid over-charging?

Pat

#30393

开云体育

Martin,

Thank you.? You have answered a lot of my questions.? Regarding my AGM charger, it may be even worse than "sub-optimal".? That charger finishes its charging cycle with a desulfation process that would be of no use to LiFePo4 batteries.? In addition, that charger is known to shut down when the battery doesn't act as expected.? It might just assume the new battery is a bad AGM battery once the internal BMS stops accepting a charge.

?

On 4/28/2020 7:58 AM, martin Thacker wrote:

Show quoted text

I've been working on a team in Germany developing some lithium?batteries and BMS for outdoor and marine usage. There are huge differences in BMS quality and feature sets but what almost every Lithium BMS would do for you is to cut off charging to the batteries when they reach a??pre determined?100% charge level to prevent you from overcharging the?pack. For LiFePO4 this will be about 3.65v for a single cell or for a 4 Series 12.8V pack that would be 14.6V.? ??

I don't have so much experience with AGM but your AGM charger is probably putting out 14.4 - 14.8V which is so close to the 14.6V that it would not be a big problem for you I would think,?not dangerous in any case.? Your BMS will shut off the charge to your batteries so that they don't go above that 14.6 level once it has been reached so?there is no risk of over charging the battery.? ?Your AGM charger will probably try to taper the charge according to a profile set for AGM so it would be sub optimal for LiFePO4.??

On Tue, Apr 28, 2020 at 12:31 PM greenpjs04 <forums@...> wrote:

Wow!? Thank you for all the responses.? I will investigate all your
suggestions further.? One topic that came up but has me confused is the
BMS needed for LiFePo4 batteries.? From past research, I know that some
cells offered for sale are just that - cells without any BMS.? To use
those, I would have to add a BMS designed for LiFePo4 chemistry.?
DualPro's website says their chargers "can" be programmed for LiFePo4
but I doubt that applies to my 10 year old AGM charger.

So, moving on to the LiFePo4 battery packs with built in BMS's, how does
one charge those?? I found very little detail mentioned. Just things
like "Includes BMS!" and similar claims.? Can any charger with a voltage
above the battery voltage be used to charge these batteries?? In other
words, does the internal BMS fully protect the batteries by handling
charge rate and monitoring state of charge to avoid over-charging?

Pat

#30394

Some bms can be customized to have a high and low bms cut offs like the ant bms I use

But since I draw too many amps I cannot use it unless I add an external contactor (maybe one day...)

So I just use it for balance

From the little I know u need cc-cv charger (I think even lead acid chargers use cc-cv but different bulk charging?)

I had a old lead acid charger that the manufacture changed to lithium charger, so it can be done?

Not sure how it was done..

If your happy with like 5-10 ? amps charging there are solar buck/boost green chargers u can buy off eBay for 30-40$ that can use variable dc input like old computer power supply and give you variable dc cc-cv output?

Ant bms..I use 32s but don’t need to use all of them. ??

Charger. ?

I’m no expert but these have worked for me and my budget?

On Tuesday, April 28, 2020, 03:32:01 AM PDT, greenpjs04 <forums@...> wrote:

Wow!? Thank you for all the responses.? I will investigate all your
suggestions further.? One topic that came up but has me confused is the
BMS needed for LiFePo4 batteries.? From past research, I know that some
cells offered for sale are just that - cells without any BMS.? To use
those, I would have to add a BMS designed for LiFePo4 chemistry.?
DualPro's website says their chargers "can" be programmed for LiFePo4
but I doubt that applies to my 10 year old AGM charger.

So, moving on to the LiFePo4 battery packs with built in BMS's, how does
one charge those?? I found very little detail mentioned. Just things
like "Includes BMS!" and similar claims.? Can any charger with a voltage
above the battery voltage be used to charge these batteries?? In other
words, does the internal BMS fully protect the batteries by handling
charge rate and monitoring state of charge to avoid over-charging?

Pat

#30395

MARTIN: Since you have expertise, I hope you'll agree that the acronym 'BMS' stands for battery management system, but that what some people are referring to as a BMS is actually a battery protection system.
A BMS that's suitable for a 16 cell, LiFePO4 prismatic pack, such as might be found aboard a sailboat -- such as the Orion Jr. or the Dilithium BMSC from Thunderstruck -- would provide for measuring and reporting individual cell voltages; balancing the cell voltages within the pack; and also often the ability to measure cell or pack temperature.? The Orion Jr even implements charger control in a single unit, while the Dilithium units from Thunderstruck separate the two functions -- BMS & charge control -- into two different units, but enables using two different modes of communication between the two devices, including CAN.
in contrast, the typical "BMS" that's embedded in 48v battery packs used for electric bicycles, for instance, provides only for the overcharge protection to shut off charging when voltage reaches the safe operating limit, and low voltage protection to shut off discharging to load when voltage drops to the safe operating level for that battery pack.
In the case of battery protection circuits, it's possible for individual cells to get out of balance relative to one another, such that one cell will reach full charge voltage before the others in a pack.? The protection circuit cuts off charging due to the high cell voltage cut-off, and the remaining cells will be less than fully charged.
Many of the ElectricBoat members are familiar with everything I've just mentioned, but it may be useful to repeat the information as new members come aboard.
Fair Winds to all!
[-tv]
Tom VanderMeulen
"Grace O'Malley"
Cape Dory 27
Monroe, Michi.

#30396

To piggy back on what Tom said,?

Its best practice to have two means of protecting batteries. On the charge side, the charger have the correct charge profile and the BMS is secondary and should only be used as back up in case the charger fails. On the discharge side, the motor controller/inverter should be programmed with the correct voltage settings and the BMS is the failsafe.?

Unless you are charging at a high C rate (most of us in DIY electric boats are not) you do not need to worry about CVCC. You can just charge with CV and stop. Unlike lead acid, which prefer to be fully charged and even over charged occasionally, lithium prefers to be less than fully charged. They would be perfectly happy sitting at 50% SOC for years.? If using a lead acid charger, turn off the float charge or make it as low as possible. Be certain it does not have an equalization charge. Overcharging lithium just once can and most likely will ruin them, sometimes in a dramatic way.?

For lifepo4 I stop charging at 3.5 VPC. There is almost no capacity above that voltage. ?If you look at a discharge chart you will see what I mean.?Lifpo4 voltages should not be confused with lithium chemistries with a 4.2 VPC cutoff?

I typically use? 90% as upper limit and 10% on the low end.?

Matt Foley?

Sunlight Conversions

Perpetual Energy, LLC

201-914-0466

On Tuesday, April 28, 2020, 09:40:12 AM EDT, THOMAS VANDERMEULEN <tvinypsi@...> wrote:

MARTIN: Since you have expertise, I hope you'll agree that the acronym 'BMS' stands for battery management system, but that what some people are referring to as a BMS is actually a battery protection system.
A BMS that's suitable for a 16 cell, LiFePO4 prismatic pack, such as might be found aboard a sailboat -- such as the Orion Jr. or the Dilithium BMSC from Thunderstruck -- would provide for measuring and reporting individual cell voltages; balancing the cell voltages within the pack; and also often the ability to measure cell or pack temperature.? The Orion Jr even implements charger control in a single unit, while the Dilithium units from Thunderstruck separate the two functions -- BMS & charge control -- into two different units, but enables using two different modes of communication between the two devices, including CAN.
in contrast, the typical "BMS" that's embedded in 48v battery packs used for electric bicycles, for instance, provides only for the overcharge protection to shut off charging when voltage reaches the safe operating limit, and low voltage protection to shut off discharging to load when voltage drops to the safe operating level for that battery pack.
In the case of battery protection circuits, it's possible for individual cells to get out of balance relative to one another, such that one cell will reach full charge voltage before the others in a pack.? The protection circuit cuts off charging due to the high cell voltage cut-off, and the remaining cells will be less than fully charged.
Many of the ElectricBoat members are familiar with everything I've just mentioned, but it may be useful to repeat the information as new members come aboard.
Fair Winds to all!
[-tv]
Tom VanderMeulen
"Grace O'Malley"
Cape Dory 27
Monroe, Michi.