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Re: Li-ion battery designer commentary
I was on the fence about LiFePo, but I have completely abandoned them.? They can work well in conjunction with one of the many super capacitor 12v boards out there that will handle CCA,? but... Story: I have installed several RV solar installations using lithium, but recently I was introduced to a carbon lead battery that has more (greater) cycle life than LiFePo, and has the ability to supply large loads.? The name of the battery is Northstar, and the series is the blue series. It is under the outback umbrella. Before you waste any more of your resources on polluting the earth, producing lithium products, download the manual for the blue series of batteries from there website.? In answer to your future questions!? Yes I am using them on my system, and yes I am recommending them.? On Wed, Dec 7, 2022, 8:12 PM sw via <v1opps=yahoo.com@groups.io> wrote:
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Re: Li-ion battery designer commentary
Buy li then make u hang around so they die first
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On Wednesday, December 7, 2022, 14:22, Daniel Wolf <danielhwolf@...> wrote:
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Re: Li-ion battery designer commentary
These are great points. For instance, I'd not thought of having an Li-ion house bank while keeping an AGM for starting. Makes a lot of sense.? I would urge people to click through to the Quora author's master page, he covers a lot of topics, some of which may help inform the discussions here rather than taking it abroad into cars and so on. Best regards, Dan? Daniel H. Wolf, Esq. Founder, CEODemocracy Counts! San Diego, CA 92104 USA 619.270.6434 Mobile Act always as if the future of the universe depends on what you do, while laughing at yourself for thinking that anything you do makes any difference. ??????????????????????????????????????????????????????????????????? ????????????????????????????? A Buddhist sayingOn Wed, Nov 30, 2022 at 12:53 PM Myles Twete <matwete@...> wrote:
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Re: Li-ion battery designer commentary
开云体育John and Cap’n Carter offer great points and advice to consider. This year I had had enough with lead acid starting batteries on my Vanagon, which only gets driven really a few times a year.? I looked at available lithium options that might work to replace the starting battery, but except for “maybe” one that checked at least most of the boxes, the price was in the higher hundred$ for a Lithium Ion option.? Sure, LiFePo options are out there, but as pointed out earlier, there are BMS and other reasons they can’t handle this application. What did I do? I made my own Lithium Ion starter battery.? It was a lot of work and ended up not fitting, so I had to carve out some metal to get it to fit, but what an amazing starter battery I have now.? Tested CCA (Battery Analyzer): 3000 CCA. While it didn’t cost me a whole lot to do, it was a lot of work. In my case, I started with a known lithium ion cell stack I have used on my boat for 31-48v use (nom. 42v, 35ah, 12S2P config).? I then disassembled all the interconnects and carefully made new ones to make a nom. 14v (4S6P) 105ah battery.? I took the existing BMS card and made custom cabling, using just 4 of the monitoring channels. ?I already use these batteries and BMS cards on my boat pack (20P(12S(2P)) configuration for 700ah capacity) where I can monitor (and bypass if needed) any of the 240 cell pairs in the pack.? For my Vanagon, there’s just 4 cell hextets to monitor. In either case, no active BMS is really needed given the operating conditions I have.? In the boat’s case, I almost never take the pack voltage below 36v and check and balance the pack about once a year (only maybe 4-7 charge cycles). In the Vanagon’s case, I measured the BMS readings at rest, during start and after charging and after a couple trips and have seen no change in differential cell voltages. ? Performance: Rock solid starting (3000CCA vs maybe 250 or less with what I typically ended up with).? Ability to disconnect and float the battery (and cells) for months or years at a time without lead-acid worry of “sulfation”.? Cost was under $300 total. ? I still need to get the thing completely parked in place.? I do have a new battery compartment lid I made, but still need to hammer out a replacement side wall.? I also finally invested in a “house power” or auxiliary battery.? In that case, I bought some of the lower cost nom. 12v LFP 25ah(?) boxes out there.? The price was right, and they fit in the cavity nicely, but boy I really do hate that these battery manufacturers get away with embedding BMS electronics that cannot be disabled or won’t self-disable during times of no discharge.? Probably every one of these out there will “self-brick” within months if left alone.? When these LFP batteries I got arrived, each one of them only read under 2volts!!!? Fortunately, literature shows that most lithium chemistries will survive “self-discharge”, just not reverse polarity (which is what you get when you serially discharge a series of cells).? Still some of these LFP manufacturers (e.g. NEC) make batteries which, like laptop smart batteries, will blow an internal fuse or otherwise lock out the battery terminals from being charged or discharged if the voltage drops, say, below 10v. ?These may be recoverable as I found with the NEC batteries, but your mileage may vary… ? One last thing: You might be thinking “Wow, you must have one heck of a beefy BMS if it can work as a starter battery!”? Actually, no.? The BMS cards I use is only good to bypass about 1amp around cell pairs. ?It’s such a trickle that it can take days or longer to balance differentials of any significance.?? And that’s okay.? As configured, a 420amp starting current will draw just 70amps per cell with my battery.? Now, that is not exactly insignificant as these are 17ah cells, so this is about a 4C draw.? However, it’s just for a very short time and the amount of amp-hours drawn during a start episode is miniscule---I measured drop in the low millivolts at the cell level during a start. ? Anyway, long wind here, but for me, very happy with lithium ion for a starter battery. ? -Myles ? ? From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of twowheelinguy via groups.io
Sent: Wednesday, November 30, 2022 12:00 PM To: electricboats@groups.io Subject: Re: [electricboats] Li-ion battery designer commentary ? I checked out the post and the guy left out one simple yet important detail. You can't use a battery with a 100amp BMS for starting your car, which is what all of the cheaper prismatic cell lithium batteries come with. Thankfully most of them will point blank tell you not to use on your car but usually it's buried in the finer print that most people don't read or even follow half the time when they do.?? ? As long as you shell out for the upgraded BMS and cells that will give you the CCA capacity you need then lithium is great but I don't think it's a better value because? the batteries that can do that are much more expensive and that brings into questions the cost effectiveness of the extra investment, especially when you can pretty much count on a decent FLA to crank your car for 6 years or more. The lithium chemistry definitely outperforms Lead by leaps and bounds but it's the long-term reliability of the BMS I worry about. If you're paying 5 times more for a Lithium battery do you really think you'll get 5 times longer life? Do you even need 5 times longer life? ? I'm a total Lithium convert and won't deny it's the near term future of energy storage. With the recent precipitous price drops, I finally converted the Arc from FLAs to? LiFePo this year and am flabbergasted at how much better they are but I think it's safe to say lead is not quite dead. Yet.? ? Capt. Carter ? On Wednesday, November 30, 2022 at 09:08:24 AM EST, Daniel Wolf <danielhwolf@...> wrote: ? ? Lurker here who enjoys all the informative info you all post. ? This came down my?Quora feed, I thought it might be of interest to you. It's by a Li-ion battery designer and he provides a lot of practical knowledge. ? Best regards, ? Dan ?
Daniel H. Wolf, Esq. Founder, CEO Democracy Counts! San Diego, CA 92104 USA 619.270.6434 Mobile ? Act always as if the future of the universe depends on what you do, while laughing at yourself for thinking that anything you do makes any difference. ??????????????????????????????????????????????????????????????????? ????????????????????????????? A Buddhist saying ?
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Re: Li-ion battery designer commentary
I checked out the post and the guy left out one simple yet important detail. You can't use a battery with a 100amp BMS for starting your car, which is what all of the cheaper prismatic cell lithium batteries come with. Thankfully most of them will point blank tell you not to use on your car but usually it's buried in the finer print that most people don't read or even follow half the time when they do.?? As long as you shell out for the upgraded BMS and cells that will give you the CCA capacity you need then lithium is great but I don't think it's a better value because? the batteries that can do that are much more expensive and that brings into questions the cost effectiveness of the extra investment, especially when you can pretty much count on a decent FLA to crank your car for 6 years or more. The lithium chemistry definitely outperforms Lead by leaps and bounds but it's the long-term reliability of the BMS I worry about. If you're paying 5 times more for a Lithium battery do you really think you'll get 5 times longer life? Do you even need 5 times longer life? I'm a total Lithium convert and won't deny it's the near term future of energy storage. With the recent precipitous price drops, I finally converted the Arc from FLAs to? LiFePo this year and am flabbergasted at how much better they are but I think it's safe to say lead is not quite dead. Yet.? Capt. Carter www.shipofimagination.com
On Wednesday, November 30, 2022 at 09:08:24 AM EST, Daniel Wolf <danielhwolf@...> wrote:
Lurker here who enjoys all the informative info you all post. This came down my?Quora feed, I thought it might be of interest to you. It's by a Li-ion battery designer and he provides a lot of practical knowledge. Best regards, Dan
Daniel H. Wolf, Esq. Founder, CEODemocracy Counts! San Diego, CA 92104 USA 619.270.6434 Mobile Act always as if the future of the universe depends on what you do, while laughing at yourself for thinking that anything you do makes any difference. ??????????????????????????????????????????????????????????????????? ????????????????????????????? A Buddhist saying |
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Re: Li-ion battery designer commentary
There were two primary concerns that I heard with respect to using Lithium drop in batteries in cars or boats as replacements for traditional lead acid or AGM batteries: 1) If the BMS detects that the battery charging is complete (or that the alternator is attempting to overcharge), the BMS will electrically disconnect the battery.? If there is no load on the alternator when the engine is running, you will typically fry the diodes in the alternator. 2) Lithium batteries can take sink high amounts of current, and can easily overwhelm a traditional alternator, leading to the alternator being burned out if the battery is deeply discharged when the engine is started. Both of the above two issues can be resolved with smart enough BMS configurations and/or alternators.? The second problem (limiting the charge current pulled by the battery) can be managed with a DC2DC charger.? I've heard there are also "black boxes" that one can get to serve as a load for the alternator if the BMS hits 'full' and disconnects the battery.?? How would one know if the specific BMS of the battery one is buying (i.e. from Amazon, from China, with little to no documentation - especially no documentation about the BMS...) is set up to allow use in a car application?? Are current "drop in replacement" 12V Lithium batteries set up to handle the above two cases? For my trawler, the best solution seems to be to use conventional AGM batteries as the starting batteries, but have a significant LFP (lithium iron phosphate) bank for the house bank.? ?I'm planning to use a Renogy 30A DC-2-DC charger that can supplement charging of the house bank when I'm under way.
On Wednesday, November 30, 2022 at 09:41:42 AM CST, Daniel Wolf <danielhwolf@...> wrote:
I should have mentioned, for those who are not familiar with Quora, that if you click on the name of the person posting the answer you get all of his or her other answers. There are many more answers and discussions of lithium battery technology there. On Wed, Nov 30, 2022, 6:08 AM Daniel Wolf via <danielhwolf=gmail.com@groups.io> wrote:
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Re: Li-ion battery designer commentary
I should have mentioned, for those who are not familiar with Quora, that if you click on the name of the person posting the answer you get all of his or her other answers. There are many more answers and discussions of lithium battery technology there. On Wed, Nov 30, 2022, 6:08 AM Daniel Wolf via <danielhwolf=gmail.com@groups.io> wrote:
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Li-ion battery designer commentary
Lurker here who enjoys all the informative info you all post. This came down my?Quora feed, I thought it might be of interest to you. It's by a Li-ion battery designer and he provides a lot of practical knowledge. Best regards, Dan
Daniel H. Wolf, Esq. Founder, CEODemocracy Counts! San Diego, CA 92104 USA 619.270.6434 Mobile Act always as if the future of the universe depends on what you do, while laughing at yourself for thinking that anything you do makes any difference. ??????????????????????????????????????????????????????????????????? ????????????????????????????? A Buddhist saying |
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Re: Combining low and high DC grounds
Yes you can. In that case you call the ground a common. You must remember your circuit must only include the ground(common) and no other voltages... To avoid back feeding on any level it is best to have completely separate systems.? A final thought! It is necessary to have control circuits tied by common unless the two are an isolated system.? Hope that helps.? On Thu, Nov 24, 2022, 9:36 AM Retreat Time via <sailorboy55577=yahoo.com@groups.io> wrote: Can someone here direct me to the right information regarding DC grounds, can 72-volt 6S batteries be commonly grounded to the same 4p house bank? |
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Re: ME1115 DSP Encoder Fault 0x52C1
Mine failed because of Lightning, good idea to keep a few spares handy. John Winterrowd 702 343 1492 4.2.1. Email Disclaimer NOTICE: The information contained in this electronic transmission is intended only for the use of the individual or entity named above. ANY DISTRIBUTION OR COPYING OF THIS MESSAGE IS PROHIBITED, except by the intended recipient. Attempts to intercept this message are in violation of 18 U.S.C. 2511(1) of the Electronic Communications Privacy Act, which subjects the interceptor to fines, imprisonment and/or civil damages. If you are not the intended recipient, please delete it and notify me. On Monday, November 7, 2022, 09:10:37 AM EST, Ryan Rolland <ryan@...> wrote: Hi Thiery, The motor is installed inside the cabin of a catalina 30 that is moored in salt water. The motor has been installed for about three years, however, this problem began to surface after a year. It had gotten worse though, i.e. less likely to not fault in the last month.? Ryan R. Sent from my Verizon, Samsung Galaxy smartphone -------- Original message -------- From: Thierry <thierry.lequeu@...> Date: 11/6/22 9:22 PM (GMT-10:00) To: electricboats@groups.io Subject: Re: [electricboats] ME1115 DSP Encoder Fault 0x52C1 Hello Ryan, I guess the environment is salty. How long has the motor been installed? It seems to me that the cover does not have a seal... Moisture can also penetrate the bearing of the rotor shaft,?normal since the?ME1115 is an open frame motor! Thierry |
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Re: ME1115 DSP Encoder Fault 0x52C1
开云体育Hi Thiery, The motor is installed inside the cabin of a catalina 30 that is moored in salt water. The motor has been installed for about three years, however, this problem began to surface after a year. It had gotten worse though, i.e. less likely to not fault in the last month.? Ryan R. Sent from my Verizon, Samsung Galaxy smartphone -------- Original message -------- From: Thierry <thierry.lequeu@...> Date: 11/6/22 9:22 PM (GMT-10:00) To: electricboats@groups.io Subject: Re: [electricboats] ME1115 DSP Encoder Fault 0x52C1 Hello Ryan,
I guess the environment is salty. How long has the motor been installed?
It seems to me that the cover does not have a seal...
Moisture can also penetrate the bearing of the rotor shaft,?normal since the?ME1115 is an open frame motor!
Thierry |
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Re: Max props have arrived
Depending on what you like to achieve probably? It sounds pretty good to me already. If it was me I would go for as little pitch as possible to try to make the propeller as efficient as possible. But I would be more interested in power to drive into wind and/or waves than try to get the highest speed possible. Would be really interesting to see what it will do with efficiency when you increase the pitch.? Op vr 4 nov. 2022 20:05 schreef Retreat Time via <sailorboy55577=yahoo.com@groups.io>: 44 ft catamaran |
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ME1115 DSP Encoder Fault 0x52C1
开云体育A frustrating problem that manifested itself in a non-repeatable way. Sharing here so as to help anyone else encountering this issue. The ME1115 would fail to start with the below error: DSP Encoder Fault 0x52C1 Encoder Input wire-off is detected This motor has a small sensor used to measure the position of the rotor: RMB29AC01SS1 *There is a small compartment on the end of the motor, opposite the drive shaft, housing this sensor. This sensor had started to corrode. A new sensor had to be ordered and installed to resolve. See attached picture. I used GE All Purpose Silicon to reseal the sensor compartment. Ryan R. Sent from my Verizon, Samsung Galaxy smartphone |
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Re: Max props have arrived
Let do some math.
2500 Max RPM divided by 3.21 = 778.8 RPM at the Prop
8 knots is approx = 9 MPH
9 MPH = 47,520 feet per hour
47,520 feet per hour = 792 ft per minute
792 ft per minute = 778.8 rotations per minute = 1.02 ft per rotation
1.02 ft per rotation is approx = 12 inches per rotation?
12 inches per rotation gives you the minimum pitch assuming that all the rotation of the prop resulted in forward motion of the boat.
Looking at the Easy Prop Table, 24 deg, 11.8" is the most they recommend.
You could go past the recommended to 30 deg, but that is a lot of pitch and at that pitch you may exceed the torque rating of the motor.
?
Can you change the reduction gears? |
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Max props have arrived
44 ft catamaran
Max prop easy18 in diameter 4 blade pitch is adjustable 16 to 24 degrees 72 volt 18 kw motor, max RPM 2500 Reductions =90-tooth bottom?pulley 28-tooth?top pulley = 3.21:1 ratio 39.5ft waterline-hull speed is close 7.8 to 8.4 knots I think the reduction is too much, I would like advice on what to set the pitch to. |
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Re: Elco vs ePropulsion
开云体育Myles, On November 2, 2022, at 12:39 PM, Myles Twete <matwete@...> wrote: The only time and situation I’ve seen people use model airplane props for hydro propulsion was for pedal powered kayaks on Vancouver Island back in 1996.? The homemade propulsion units were based on the Eide SeaCycle pedal units but made much narrower, light weight and with a spring-loaded mounting arrangement that allowed the prop and water leg to pop up thru a dagger slot when the unit hit something as it was going along. ?The person who made these called the resulting pedal kayaks “Kawaks”.? They were super fast---we pedaled our Seacycle catamaran at top speed while pacing with the person who invented the Kawak drive.? Knowing the Seacycle was supposed to hit about 10mph at top speed, Bob called to me and said “is that as fast as you can go?”---then he pushed his pedal drive faster and took off ahead of us.? He told me that large model airplane propellers worked well for his drives. ? -mt ? From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of cpcanoesailor via ?
I first did some boat speed and electrical power measurements using the stock prop that came with the motor, to get a performance baseline. |
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Re: Elco vs ePropulsion
Any suggested size pitch for a 24v ? ?Thx?
On Wednesday, November 2, 2022, 07:29:34 AM PDT, cpcanoesailor via groups.io <cpcanoesailor@...> wrote:
Has anybody tried or know how to pick a model airplane prop for electric outboard?I first did some boat speed and electrical power measurements using the stock prop that came with the motor, to get a performance baseline. I read an article that said prop efficiency increases with diameter, so I determined how large a prop could I reasonably use with my motor, based on submerged depth, length of the skeg, etc. I also estimated the pitch of the stock prop. Then I translated that pitch value to the larger prop size to get the pitch number for a similar speed performance (but now more efficient). That gave me an idea of which pitch numbers to look for in the larger sized airplane props. In my case, I thought I wanted about twice the pitch of the stock prop, since the motor was hitting its RPM limit but drawing only half the rated current. That actually worked out well for me - the motor with the larger, higher pitched prop now draws rated current at max RPM. And power measurements indicate that for a given speed, the new prop takes noticeably less electrical power than the stock prop did. One downside to slim airplane props is they slip a lot more than standard marine props. This is only a problem if you're pushing your boat into a strong wind, or trying to tow a heavy load with lots of drag. For me, on a sailboat, it's not a serious issue. But I do keep the stock prop and a wrench in the bilge... |