Lithium battery upgrade questions

[rubicon327]

Originally Posted by Semievolved

FWIW, I just bought a 400Ah battery from BESTGO through electric car parts company in Utah and am very happy with it. Wasn't cheap, $1900, but it tested out well above capacity (430.6Ah from 14.6V down to 11.2V), is in a very nice, weather proof, sturdy aluminum case with meter. They have a solid warranty of > 3000 full discharge cycles.

Dave: I’m very intrigued with this battery you mention. 400AH for close to the price of 200AH if I went with two Battle Born.
https://www.electriccarpartscompany....-battery-packs

The specs all look ok at face value but I’m concerned with page 6 of the spec sheets. It lists four specialized tests that “should be conducted on new batteries within three months after receiving the batteries”. These tests seem beyond the ability of a typical buyer. Unless that typical buyer is an electric car company. Am I missing something?

[Semievolved]

Originally Posted by rubicon327

Dave: I’m very intrigued with this battery you mention. 400AH for close to the price of 200AH if I went with two Battle Born.
https://www.electriccarpartscompany....-battery-packs

The specs all look ok at face value but I’m concerned with page 6 of the spec sheets. It lists four specialized tests that “should be conducted on new batteries within three months after receiving the batteries”. These tests seem beyond the ability of a typical buyer. Unless that typical buyer is an electric car company. Am I missing something?

Thanks much for pointing that out. I think I must have scanned that and assumed it was testing done on cells/battery before purchase. I just emailed Tony, the main dude at Bestgo asking what is meant by that since clearly that is testing well out of the range of most users. Plus, I wouldn't want to do several of those tests to a battery - direct short?, no way. He's been excellent about getting back to me quickly with solid answers so I will update when I hear from him.



BTW, if someone is considering this battery and wants more of the tech details about construction etc that Tony has provided I can dig those up and email to you.

[Semievolved]

Originally Posted by rubicon327

Dave: I’m very intrigued with this battery you mention. 400AH for close to the price of 200AH if I went with two Battle Born.
https://www.electriccarpartscompany....-battery-packs

The specs all look ok at face value but I’m concerned with page 6 of the spec sheets. It lists four specialized tests that “should be conducted on new batteries within three months after receiving the batteries”. These tests seem beyond the ability of a typical buyer. Unless that typical buyer is an electric car company. Am I missing something?

Lightning fast response from Tony at Bestgo:


Dave,
Sorry for misunderstanding, it just means if any test lab want to test our batteries, should take new batteries but not old batteries. And we promise our battery packs can pass those tests as we specified in datasheet, it is a formatted description in our regular datasheet of batteries, and those preferred battery packs already passed UN38.3, so do not too much worry about them.
Best wishes, Tony Tang

[rubicon327]

Originally Posted by Semievolved

Lightning fast response from Tony at Bestgo:


Dave,
Sorry for misunderstanding, it just means if any test lab want to test our batteries, should take new batteries but not old batteries. And we promise our battery packs can pass those tests as we specified in datasheet, it is a formatted description in our regular datasheet of batteries, and those preferred battery packs already passed UN38.3, so do not too much worry about them.
Best wishes, Tony Tang

Thanks Dave. Curious as to how they get 400AH in a 178.5 sq. in. footprint but (4) 100AH BattleBorn's would be around 350 sq. in. That's twice as much area and the battery heights are similar. Also weight for Bestgo is 89# where four Battleborns would be 124#. That's a significant difference.

I'm going to send you a PM with my email. If you have the documentation that Tony has sent you on this battery I would appreciate having it. Thanks.

[Semievolved]

Not sure, maybe it's because each of the BBs has a case whereas the Bestgo is 4 x 105Ah cells packed tightly together and then cased? I did confirm the measurements though and it's only 10.25" tall. Bestgo weighs 91#. I dunno enough about the BBs to comment on weight/size differences other than what I suggested above about casing differences.
I got your PM; I believe you already have the published specs but I will pull together various emails where Tony describes their manufacturing process. Very interesting.

[glsails]

We just took delivery of our 2021 21C on Monday this week. This is our third trailer, but our first Escape and our first experience using Lithium battery tech. Our last trailer was a 1999 with flooded lead-acid batteries and a much older technology charging and converter (ac/dc switching) system.

I had a rather weird experience with the system on the Escape the other day and was just wondering if anyone can provide any insight:

I unplugged the 40 amp fuse on the trailer tongue that is for the electric jack. I just was exploring the system to see if I might find a spot to hook up a hidden jack switch. After I plugged the fuse back in, the jack would not work. Checked all fuses and breakers and everything was good. In fact, when I tried to use the 12v system, nothing would work. I know that the jack is directly connected to the batteries and does not run through the converter. I believe the only other thing with a direct battery connection would be the emergency break-away switch for the trailer brakes, which I didn't test.

Anyway, I plugged the trailer into shore power back in and everything worked, except the electric jack, which meant the converter was working properly but that the batteries were not powering anything. The EMS showed no problems, code E-0. Big relief there.

When I'd unplug the shore power, the entire system would go dark. No battery power anywhere. When I turned the master battery shut off key on or off, nothing happened. When it was hooked up to shore power, the solar charging control showed both batteries at 100% charged. I was frustrated and worried about our two day old Escape (with Li Po batteries that cost a fortune) already having a major electrical issue, that I'd probably caused by screwing around with that jack fuse. Went back in the house vowing to check in with ETI in the morning. I figured some kind of fuse-able link or breaker between the batteries and the master battery shut-off switch must exist and have been triggered. Went to sleep worried it might not be that simple.

The next morning, before I called ETI, I went out to the trailer and noticed that the solar management system was showing a readout. I tried the lights and a few other 12v items and the entire 12v system was back up and running perfectly. The electric jack was functioning too. The system continues to work perfectly, 24 hours later. So, somehow the 12v system had self-corrected. Maybe it was the thoughts and prayers??

I know that the lithium batteries have a built in management system that can shut them down if a short circuit or a few other situations occur. Wondering if that is what must have happened? That's my theory anyhow and it seems pretty logical. I must have shorted when I plugged the 40 amp fuse back in for the jack, triggering the battery management system to shut down the battery power temporarily.


I don't miss flooded batteries but with new tech comes the opportunity for me to do some dumb move that triggers a shut-off because the batteries are way smarter than I am. Would love to know if anyone else has any insights into the lithium system management. I'd like to avoid doing this again in the future.

[kavm]

Thank you for posting! We are 2 months away from taking our delivery - with similar electrical setup. Not likely to go experimenting but interested in learning...

[HABBERDABBER]

My EMS has about a 2 minute delay before it "kicks in". This delay is, I've read, to prevent the AC from a restart too soon.

[Centex]

Originally Posted by rubicon327

Curious as to how they get 400AH in a 178.5 sq. in. footprint but (4) 100AH BattleBorn's would be around 350 sq. in. That's twice as much area and the battery heights are similar. Also weight for Bestgo is 89# where four Battleborns would be 124#. That's a significant difference.

I'm certainly no expert on the subject but note that the (BestGo) 12V 400Ah Preferred LiFePO4 Lithium Battery Pack is assembled using "Aluminum case prismatic cells" and "aluminum busbars".

BattleBorn, on the other hand, assembles its batteries using "stainless-steel cylindrical lithium-ion battery cells" with "Lengthways circuit boards between each layer of cells [to] monitor current, temperature and pressure" and the "main bus bar is 1/8 x 3/4" solid copper".

Not at all commenting on whether one is 'better' than the other, but there do seem to be significant differences in their approach to internal components / construction / assembly which perhaps account for the physical (weight and volume) differences you've noted, Dave ('rubicon Dave', that is )?

[Semievolved]

I sure don't know. But, if Bestgo can produce a smaller, lighter, less expensive battery that is guaranteed to produce more than 3000 full charge/discharge cycles and still retain 80% capacity, and carry a 5 year warranty it seems like a good product. Honestly, for me the biggest hurdle toward buying it was a strong desire to buy a United States product rather than Chinese.

[gbaglo]

Originally Posted by Semievolved

Honestly, for me the biggest hurdle toward buying it was a strong desire to buy a United States product rather than Chinese.

Do you know what the Chinese do with that money? They use it to buy American corn and grain, and cars, and software...

[Semievolved]

Originally Posted by gbaglo

Do you know what the Chinese do with that money? They use it to buy American corn and grain, and cars, and software...

this is ripe for thread derail, but, first concern was caused by earlier rip off from Chinese Alibaba vendor which leaves little room for recourse; didn't want to repeat that experience. In terms of what the Chinese do with the money, that's a separate argument. I was mainly referring to labor and enviromnetal laws which I feel strongly favor Chinese manufacturers over Americans. Please feel free to email me if you wish to continue discussion dharry686@gmail.com

[NEWYORKHILLBILLY]

I think that the 40 amp fuse also stopped power from going to solar controller. solar system is wired before the switch so when the switch is off the controller still has power . If the controller is not powered it possible that more volts went to the battery and the internal bms shut it down. This is just my guess, there not to many of there new systems out to compare.

[Brian B-P]

Originally Posted by glsails

I unplugged the 40 amp fuse on the trailer tongue that is for the electric jack. I just was exploring the system to see if I might find a spot to hook up a hidden jack switch. After I plugged the fuse back in, the jack would not work. Checked all fuses and breakers and everything was good. In fact, when I tried to use the 12v system, nothing would work.

Did all of those 12 V things work before the jack circuit test? If the battery was so discharged that it shut down, or a fuse at the battery was blown, it would explain the lack of 12 V power to anything without the converter running.

Originally Posted by glsails

I know that the jack is directly connected to the batteries and does not run through the converter. I believe the only other thing with a direct battery connection would be the emergency break-away switch for the trailer brakes, which I didn't test.

That's probably correct. Although it varies by model, those with the battery and electrical panels in the back tend to have the jack on the same wire as the battery to tow vehicle connection... so powered by the battery when the storage/use switch is in the storage position.

Originally Posted by glsails

Anyway, I plugged the trailer into shore power back in and everything worked, except the electric jack, which meant the converter was working properly but that the batteries were not powering anything.

That would only make sense if the storage/use switch is in the "storage" position and the battery is shut off by the internal protection (or isolated by a blown fuse), or the jack fuse was still out. Even with no battery installed, the converter will still power the jack if the storage/use switch is in the "use" position.

Originally Posted by glsails

When I'd unplug the shore power, the entire system would go dark. No battery power anywhere. When I turned the master battery shut off key on or off, nothing happened.

That's consistent with the battery shut off by its protective system or a fuse at the battery blown... and if you didn't replace a fuse at the battery later, it couldn't have been a fuse.

Originally Posted by glsails

When it was hooked up to shore power, the solar charging control showed both batteries at 100% charged.

The solar charger only sees voltage; it has no idea if the battery is charged or not. With the shore power on, the converter supplies voltage which corresponds to a charged battery... even if there is no battery installed.

Originally Posted by glsails

I figured some kind of fuse-able link or breaker between the batteries and the master battery shut-off switch must exist and have been triggered. Went to sleep worried it might not be that simple.

The next morning, before I called ETI, I went out to the trailer and noticed that the solar management system was showing a readout. I tried the lights and a few other 12v items and the entire 12v system was back up and running perfectly. The electric jack was functioning too. The system continues to work perfectly, 24 hours later. So, somehow the 12v system had self-corrected...

I know that the lithium batteries have a built in management system that can shut them down if a short circuit or a few other situations occur. Wondering if that is what must have happened? That's my theory anyhow and it seems pretty logical. I must have shorted when I plugged the 40 amp fuse back in for the jack, triggering the battery management system to shut down the battery power temporarily.

I agree. The "self correction" can simply be the solar charging system recharging the battery after the battery management system (built into the batteries) resets from a low-voltage shutdown.

It's hard to tell remotely, but it looks to me more like the battery was just completely run down than an overload. For a couple hundred amps to flow when the jack fuse was replaced makes no sense unless there was a short, and that would have blown the jack fuse (and likely would have been noticeably dramatic).

[Brian B-P]

Originally Posted by Semievolved

Honestly, for me the biggest hurdle toward buying it was a strong desire to buy a United States product rather than Chinese.

Skipping the whole question of the merits or lack thereof of "buy American" ... are the cells used by Bestgo made in the United States? That would be surprising.

I assume that the Bestgo products are, if not made in China, assembled in the U.S. with all major components (cells and BMS) made in China. Presumably the same is true of BattleBorn.

I note this in a Bestgo product sheet

Cells used in pack belongs to electric vehicle level cells (VDA cells), cells have passed the highest level of on road test in China, they have been massive used in high speed electric vehicles in China.

[Brian B-P]

Originally Posted by Centex

I'm certainly no expert on the subject but note that the (BestGo) 12V 400Ah Preferred LiFePO4 Lithium Battery Pack is assembled using "Aluminum case prismatic cells" and "aluminum busbars".

BattleBorn, on the other hand, assembles its batteries using "stainless-steel cylindrical lithium-ion battery cells" with "Lengthways circuit boards between each layer of cells [to] monitor current, temperature and pressure" and the "main bus bar is 1/8 x 3/4" solid copper".

Not at all commenting on whether one is 'better' than the other, but there do seem to be significant differences in their approach to internal components / construction / assembly which perhaps account for the physical (weight and volume) differences you've noted, Dave ('rubicon Dave', that is )?

I think this is an excellent observation. Bestgo's prismatic cells are packed very densely; even ideally packed cylindrical cells don't pack nearly as densely, and like many small-time battery manufacturers BattleBorn arranges the cells in a rectangular array instead of the ideal close-packed hexagonal array. The volume difference isn't surprising.

Also, putting 400 Ah of cells in one battery instead of 100 Ah of cells in each of four independent batteries means one BMS instead of four. The doesn't save a lot of weight, but it certainly saves volume (and cost).

Just based on the photos provided by the Bestgo retailer and the teardown video of the BattleBorn units shared in previous discussions, the Bestgo appears to me to be the preferable construction.

[rubicon327]

Originally Posted by Semievolved

I got your PM; I believe you already have the published specs but I will pull together various emails where Tony describes their manufacturing process. Very interesting.

Dave: Thanks for the information you provided. I see you noted that the integral battery monitor provided has some error in the current reading. Would you recommend interfacing this battery with something like a Victron BMV-712 for better accuracy?

[rubicon327]

Originally Posted by Brian B-P

Skipping the whole question of the merits or lack thereof of "buy American" ... are the cells used by Bestgo made in the United States? That would be surprising.

I assume that the Bestgo products are, if not made in China, assembled in the U.S. with all major components (cells and BMS) made in China. Presumably the same is true of BattleBorn.

The Bestgo batteries are made in China and ship as a complete assembly. I believe Dave (Semievolved) was referring to the fact that he would have rather bought a battery made in the U.S. - if it were available.

[rubicon327]

Originally Posted by Semievolved

My issue is how to set up a programmable low voltage cutoff. I don't want to count on the internal BMS which is set to cutout at 2.5v/cell (10V battery) because I don't want the battery to ever go below 3.0V/cell or 12V. The Gopower inverter does not seem to have a programmable cutoff. Not trying to derail the thread here, just posting a solid LFP option for your consideration and a question hoping someone has a quick answer.

Dave...by the way I found an inverter with user defined shutoff level at purchase or programmable. Might eliminate needing to do something external. I,m glad you mentioned this issue because I am starting from scratch and this will be a nice feature to have to protect the battery.

https://purkeys.net/product/1500-pur...th-controller/

[rubicon327]

Originally Posted by rubicon327

Dave...by the way I found an inverter with user defined shutoff level at purchase or programmable. Might eliminate needing to do something external. I,m glad you mentioned this issue because I am starting from scratch and this will be a nice feature to have to protect the battery.

https://purkeys.net/product/1500-pur...th-controller/

Actually upon further review this may not work well with a lithium battery under high load. It appears it accommodates for the voltage sag which would be more characteristic of lead acid batteries...