Re: Battery and tire recommendations for Citi Car

#19115

Hi John,

thanks for the good info and pictures.? Please answer these questions if you can.

John

What was the reason to replace some of the 6 volt batteries with 8 volt options? Was it to increase the supply voltage to the motor or for other accessories?? I have read that up to 72 volts might not hurt the motor but didn't it take a different charger to charge your battery string?? I still have the original charger.
What amp rating 6 volt lead acid batteries are recommended for a system with the original contactor assembly?? I don't need 40 mile distances but the higher speed would be nice and long life of the batteries too.
Your solution seems like an overdrive feature that is only activated when the speed/voltage was right to bypass the loss in the controller.? Do you think controlling this with a switch that was disconnected once the gas pedal was no longer pushed?
If you were to do anything different today would you use lead acid batteries?

On Wednesday, June 29, 2022 at 09:23:49 AM CDT, NeonJohn <jgd@...> wrote:

On 6/17/22 22:33, Lonnie Caldwell via groups.io wrote:
> I bought new 6v golf car batteries three years ago at Sam’s Club for
>? about $85 each. A friend told me to replace two of them with 8v
> batteries. I don’t know about tires but I think you can get tires and
>? wheels already assembled at Walmart for about the same price as
> tires alone. If you want to get more miles out of it you should
> replace the unit that controls the speed with a much newer type.

Do NOT replace the old contact controller with a solid state controller
unless you want to get out and push!!!

Before I stepped my car up to 72 volts and ruggedized the motor

I had my 1000 amp Tong Tester clamp-on ammeter pegged hard when I went
wide open from a stop, something necessary to keep up with downtown traffic.

I followed conventional wisdom and bought an
Alltrax 72600 controller.? 72 volts, 600 amps.? I installed it and the
first time I started off, I felt like Fred Flinstone - I needed to
pedal, the car was so sluggish. at that time I owned some restaurants
and used the c-car for deliveries.? On one frequent route, the car could
no longer make it up a hill it formerly climbed easily.

Something had to be done.? Being a nuclear and electronics design
engineer, I decided to design a controller bypass board.? Being worried
that hitting the motor at low speed with 72 volts might twist off the
shaft or break the diff, my bypass circuit that looked at the motor
voltage, an indicator of speed, and delayed pulling in one of the old
contactors until the speed was high enough.? This cut the controller
completely out.? The circuit was activated from a microswitch
permissive, positioned so that the switch was thrown when the throttle
reached wide open.

This worked for several years until I sold the restaurants and the
C-cars and retired to my mountain home.

John

--
John DeArmond
jgd@...
jgd@...

Re: Battery and tire recommendations for Citi Car

#19114

On 6/17/22 22:33, Lonnie Caldwell via groups.io wrote:
I bought new 6v golf car batteries three years ago at Sam’s Club for
 about $85 each. A friend told me to replace two of them with 8v batteries. I don’t know about tires but I think you can get tires and
 wheels already assembled at Walmart for about the same price as
tires alone. If you want to get more miles out of it you should
replace the unit that controls the speed with a much newer type.Do NOT replace the old contact controller with a solid state controller unless you want to get out and push!!!

Before I stepped my car up to 72 volts and ruggedized the motor


I had my 1000 amp Tong Tester clamp-on ammeter pegged hard when I went wide open from a stop, something necessary to keep up with downtown traffic.

I followed conventional wisdom and bought an
Alltrax 72600 controller.  72 volts, 600 amps.  I installed it and the first time I started off, I felt like Fred Flinstone - I needed to pedal, the car was so sluggish. at that time I owned some restaurants and used the c-car for deliveries.  On one frequent route, the car could no longer make it up a hill it formerly climbed easily.

Something had to be done.  Being a nuclear and electronics design engineer, I decided to design a controller bypass board.  Being worried that hitting the motor at low speed with 72 volts might twist off the shaft or break the diff, my bypass circuit that looked at the motor voltage, an indicator of speed, and delayed pulling in one of the old contactors until the speed was high enough.  This cut the controller completely out.  The circuit was activated from a microswitch permissive, positioned so that the switch was thrown when the throttle reached wide open.

This worked for several years until I sold the restaurants and the C-cars and retired to my mountain home.

John


-- 
John DeArmond
jgd@...
jgd@...

Re: Battery Hookup source, details

#19113

It stands for battery management system - at the most basic level, they make sure all cells remain at the same voltage. Fancier ones can do things like count amp hours and tell you how much current is passing in/out of the batteries.

Show quoted text

On Sat, Jun 18, 2022, 1:39 PM Lonnie Caldwell via <lon.caldwell=[email protected]> wrote:

What is a BMS?

On Saturday, June 18, 2022, 3:35 PM, cheesewedge@... wrote:
If you skip the bms park your car far away from you house.

And miles away from mine

Re: Battery Hookup source, details

Lonnie Caldwell

#19112

What is a BMS?

Show quoted text

On Saturday, June 18, 2022, 3:35 PM, cheesewedge@... wrote:

If you skip the bms park your car far away from you house.

And miles away from mine

Re: Battery Hookup source, details

#19111

If you skip the bms park your car far away from you house.

And miles away from mine

Re: Battery Hookup source, details

#19110

Hi Jacob and All,

? ? All true and generally excellent advice except facts on Volt says it doesn't need them has been proven.? I gave the facts, use them as you want.? But I'm not paying more for a BMS than modules cost that have their own problems,? unless needed.

Nor am I the only one, very few of the 1,000s that use Volt modules now, certain LG cell modules of other EVs like BMW, Volvo,? have had excellent service, life with them.

Just check the cells to make sure they are staying in balance.? If they get out of balance which hasn't happened in the many I've used, sold to other EVers , just put a BMS on it.?

And to show just how good they are for Volt modules in 3 yrs without a BMS, the cells are still within 1/100th a Volt of each other.

Others get the same result. Check on youtube for many examples.??

Jerry

On Saturday, June 18, 2022, 09:47:07 AM PDT, Jacob <jacobtimothyfield@...> wrote:

Not using a BMS is a recipe for firey disaster if anything ever goes wrong. You can probably get away with it since the cells are healthy and aging pretty equally, but the purpose of a BMS is to make sure each cell in series doesn't overcharge or over discharge. If either condition occurs for too long, it can result in damage that can cause thermal runaway, and lithium fires are not fun.

(Seen the videos of the Chevy Bolts on fire? That kind of fire.)

The biggest danger is that your charger could be charging your string of series cells to the right overall voltage, but one might not charge to the right level, leaving the rest at a higher than normal state of charge, accelerating wear, and getting closer to a thermal runaway event - and you can't tell unless you're checking individual cell levels, because the charger only knows the voltage of the entire string, not each cell.?

Simple BMSs aren't very expensive, nor are they difficult to install. I'd highly recommend using them with any lithium battery pack.

That being said - you definitely can get away with not using one, but you should know the risks, and I personally feel like the safety justifies the little bit of extra cost and work of adding a BMS.

- Jacob

Show quoted text

On Sat, Jun 18, 2022, 9:38 AM jerry freedomev via <freedomev=[email protected]> wrote:

Hi Jacob and All,
? BatteryHookup has some great deals in Bolt like modules, not sure which model they came from.? ?But other than size they are Bolt/LG cells in different size packages.
I use new Bolt modules in my S-10EV I bought from them at great prices.
I've never used a BMS on my Volt modules for 3 yrs without any problem, still perfectly balanced and the Bolt are working out the same.
The Bolt module type is much better for a BMS as? 240amphr cells vs Volt has to be modules in parallel would need 5x more BMS.
I picked them because Volt modules were known to not need a BMS, a costly PITA and took a gamble that Bolt modules would too for overall low cost/kwh.
What you do need is a charger that won't go over 4.12vdc/cell x # of cells.?
Jerry

On Saturday, June 18, 2022, 08:39:19 AM PDT, Jacob <jacobtimothyfield@...> wrote:

If you wanted to use lithium batteries, my recommendation would be to use Chevy Volt modules and upgrade to a more modern speed controller. If you care more about driveability than originality, this is the best option. Lead acid and the original speed controller are less comfortable and the batteries won't last as long.

The biggest issue is you'd need to get a BMS and a new charger, and redo some wiring. This is a bit of a learning curve, but not that bad.

Something like the above would be perfect.?

Total cost would probably be around $1-3k depending on how fancy you want your speed controller and how much range you wanted.

- Jacob

On Fri, Jun 17, 2022, 7:27 PM john Ledermann <thelederfam@...> wrote:
Hello,
I have a working 1975 citi car that hasn't been used for a few years because I didn't want to buy the wrong batteries and I thought they wouldn't last long due to limited use.? Now that gas it so high I am thinking maybe now is the time.? I have read multiple posts over the last few years about battery options different than the normal golf cart 6v batteries and the required chargers and battery managers.

IF you have current estimates for either tires or a battery set please reply so I can consider putting this car into service again.
thanks,
John

Re: Battery Hookup source, details

#19109

Not using a BMS is a recipe for firey disaster if anything ever goes wrong. You can probably get away with it since the cells are healthy and aging pretty equally, but the purpose of a BMS is to make sure each cell in series doesn't overcharge or over discharge. If either condition occurs for too long, it can result in damage that can cause thermal runaway, and lithium fires are not fun.

(Seen the videos of the Chevy Bolts on fire? That kind of fire.)

The biggest danger is that your charger could be charging your string of series cells to the right overall voltage, but one might not charge to the right level, leaving the rest at a higher than normal state of charge, accelerating wear, and getting closer to a thermal runaway event - and you can't tell unless you're checking individual cell levels, because the charger only knows the voltage of the entire string, not each cell.?

Simple BMSs aren't very expensive, nor are they difficult to install. I'd highly recommend using them with any lithium battery pack.

That being said - you definitely can get away with not using one, but you should know the risks, and I personally feel like the safety justifies the little bit of extra cost and work of adding a BMS.

- Jacob

Show quoted text

On Sat, Jun 18, 2022, 9:38 AM jerry freedomev via <freedomev=[email protected]> wrote:

Hi Jacob and All,
? BatteryHookup has some great deals in Bolt like modules, not sure which model they came from.? ?But other than size they are Bolt/LG cells in different size packages.
I use new Bolt modules in my S-10EV I bought from them at great prices.
I've never used a BMS on my Volt modules for 3 yrs without any problem, still perfectly balanced and the Bolt are working out the same.
The Bolt module type is much better for a BMS as? 240amphr cells vs Volt has to be modules in parallel would need 5x more BMS.
I picked them because Volt modules were known to not need a BMS, a costly PITA and took a gamble that Bolt modules would too for overall low cost/kwh.
What you do need is a charger that won't go over 4.12vdc/cell x # of cells.?
Jerry

On Saturday, June 18, 2022, 08:39:19 AM PDT, Jacob <jacobtimothyfield@...> wrote:

If you wanted to use lithium batteries, my recommendation would be to use Chevy Volt modules and upgrade to a more modern speed controller. If you care more about driveability than originality, this is the best option. Lead acid and the original speed controller are less comfortable and the batteries won't last as long.

The biggest issue is you'd need to get a BMS and a new charger, and redo some wiring. This is a bit of a learning curve, but not that bad.

Something like the above would be perfect.?

Total cost would probably be around $1-3k depending on how fancy you want your speed controller and how much range you wanted.

- Jacob

On Fri, Jun 17, 2022, 7:27 PM john Ledermann <thelederfam@...> wrote:
Hello,
I have a working 1975 citi car that hasn't been used for a few years because I didn't want to buy the wrong batteries and I thought they wouldn't last long due to limited use.? Now that gas it so high I am thinking maybe now is the time.? I have read multiple posts over the last few years about battery options different than the normal golf cart 6v batteries and the required chargers and battery managers.

IF you have current estimates for either tires or a battery set please reply so I can consider putting this car into service again.
thanks,
John

Re: Battery Hookup source, details

#19108

Hi Jacob and All,

? BatteryHookup has some great deals in Bolt like modules, not sure which model they came from.? ?But other than size they are Bolt/LG cells in different size packages.

I use new Bolt modules in my S-10EV I bought from them at great prices.

I've never used a BMS on my Volt modules for 3 yrs without any problem, still perfectly balanced and the Bolt are working out the same.

The Bolt module type is much better for a BMS as? 240amphr cells vs Volt has to be modules in parallel would need 5x more BMS.

I picked them because Volt modules were known to not need a BMS, a costly PITA and took a gamble that Bolt modules would too for overall low cost/kwh.

What you do need is a charger that won't go over 4.12vdc/cell x # of cells.?

Jerry

On Saturday, June 18, 2022, 08:39:19 AM PDT, Jacob <jacobtimothyfield@...> wrote:

If you wanted to use lithium batteries, my recommendation would be to use Chevy Volt modules and upgrade to a more modern speed controller. If you care more about driveability than originality, this is the best option. Lead acid and the original speed controller are less comfortable and the batteries won't last as long.

The biggest issue is you'd need to get a BMS and a new charger, and redo some wiring. This is a bit of a learning curve, but not that bad.

Something like the above would be perfect.?

Total cost would probably be around $1-3k depending on how fancy you want your speed controller and how much range you wanted.

- Jacob

Show quoted text

On Fri, Jun 17, 2022, 7:27 PM john Ledermann <thelederfam@...> wrote:

Hello,
I have a working 1975 citi car that hasn't been used for a few years because I didn't want to buy the wrong batteries and I thought they wouldn't last long due to limited use.? Now that gas it so high I am thinking maybe now is the time.? I have read multiple posts over the last few years about battery options different than the normal golf cart 6v batteries and the required chargers and battery managers.

IF you have current estimates for either tires or a battery set please reply so I can consider putting this car into service again.
thanks,
John

Re: Battery and tire recommendations for Citi Car

#19107

If you wanted to use lithium batteries, my recommendation would be to use Chevy Volt modules and upgrade to a more modern speed controller. If you care more about driveability than originality, this is the best option. Lead acid and the original speed controller are less comfortable and the batteries won't last as long.

The biggest issue is you'd need to get a BMS and a new charger, and redo some wiring. This is a bit of a learning curve, but not that bad.

Something like the above would be perfect.?

Total cost would probably be around $1-3k depending on how fancy you want your speed controller and how much range you wanted.

- Jacob

Show quoted text

On Fri, Jun 17, 2022, 7:27 PM john Ledermann <thelederfam@...> wrote:

Hello,
I have a working 1975 citi car that hasn't been used for a few years because I didn't want to buy the wrong batteries and I thought they wouldn't last long due to limited use.? Now that gas it so high I am thinking maybe now is the time.? I have read multiple posts over the last few years about battery options different than the normal golf cart 6v batteries and the required chargers and battery managers.

IF you have current estimates for either tires or a battery set please reply so I can consider putting this car into service again.
thanks,
John

Re: Battery and tire recommendations for Citi Car

#19106

The 6 volt lead acid batteries that I used in the 74 CITICAR WORKED fine. . John Iozza from Boston. 978 930 7435

Show quoted text

On Jun 17, 2022 9:54 PM, Tom Rymes <tom@...> wrote:

I would advise against fitting trailer tires, as they ride like they are made of stone, and are terrible in terms of steering and directional stability.

Coker sells a set of 125R12 Michelin radials that a miles ahead, though certainly not the cheapest option.

Tom

On Jun 17, 2022, at 10:33 PM, Lonnie Caldwell via groups.io <lon.caldwell@...> wrote:

? I bought new 6v golf car batteries three years ago at Sam’s Club for about $85 each. A friend told me to replace two of them with 8v batteries. I don’t know about tires but I think you can get tires and wheels already assembled at Walmart for about the same price as tires alone. If you want to get more miles out of it you should replace the unit that controls the speed with a much newer type.

If you want to sell it I may be into.

Thanks?
Lonnie

On Friday, June 17, 2022, 9:27 PM, john Ledermann <thelederfam@...> wrote:
Hello,
I have a working 1975 citi car that hasn't been used for a few years because I didn't want to buy the wrong batteries and I thought they wouldn't last long due to limited use.? Now that gas it so high I am thinking maybe now is the time.? I have read multiple posts over the last few years about battery options different than the normal golf cart 6v batteries and the required chargers and battery managers.

IF you have current estimates for either tires or a battery set please reply so I can consider putting this car into service again.
thanks,
John

Re: Battery and tire recommendations for Citi Car

#19105

开云体育

I would advise against fitting trailer tires, as they ride like they are made of stone, and are terrible in terms of steering and directional stability.

Coker sells a set of 125R12 Michelin radials that a miles ahead, though certainly not the cheapest option.

Tom

Show quoted text

On Jun 17, 2022, at 10:33 PM, Lonnie Caldwell via groups.io <lon.caldwell@...> wrote:

? I bought new 6v golf car batteries three years ago at Sam’s Club for about $85 each. A friend told me to replace two of them with 8v batteries. I don’t know about tires but I think you can get tires and wheels already assembled at Walmart for about the same price as tires alone. If you want to get more miles out of it you should replace the unit that controls the speed with a much newer type.

If you want to sell it I may be into.

Thanks?
Lonnie

On Friday, June 17, 2022, 9:27 PM, john Ledermann <thelederfam@...> wrote:
Hello,
I have a working 1975 citi car that hasn't been used for a few years because I didn't want to buy the wrong batteries and I thought they wouldn't last long due to limited use.? Now that gas it so high I am thinking maybe now is the time.? I have read multiple posts over the last few years about battery options different than the normal golf cart 6v batteries and the required chargers and battery managers.

IF you have current estimates for either tires or a battery set please reply so I can consider putting this car into service again.
thanks,
John

Re: Battery and tire recommendations for Citi Car

Lonnie Caldwell

#19104

I bought new 6v golf car batteries three years ago at Sam’s Club for about $85 each. A friend told me to replace two of them with 8v batteries. I don’t know about tires but I think you can get tires and wheels already assembled at Walmart for about the same price as tires alone. If you want to get more miles out of it you should replace the unit that controls the speed with a much newer type.

If you want to sell it I may be into.

Thanks?

Lonnie

Show quoted text

On Friday, June 17, 2022, 9:27 PM, john Ledermann <thelederfam@...> wrote:

Hello,
I have a working 1975 citi car that hasn't been used for a few years because I didn't want to buy the wrong batteries and I thought they wouldn't last long due to limited use.? Now that gas it so high I am thinking maybe now is the time.? I have read multiple posts over the last few years about battery options different than the normal golf cart 6v batteries and the required chargers and battery managers.

IF you have current estimates for either tires or a battery set please reply so I can consider putting this car into service again.
thanks,
John

Battery and tire recommendations for Citi Car

#19103

Hello,
I have a working 1975 citi car that hasn't been used for a few years because I didn't want to buy the wrong batteries and I thought they wouldn't last long due to limited use.? Now that gas it so high I am thinking maybe now is the time.? I have read multiple posts over the last few years about battery options different than the normal golf cart 6v batteries and the required chargers and battery managers.

IF you have current estimates for either tires or a battery set please reply so I can consider putting this car into service again.
thanks,
John