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New Battery on Amazon and Ebay - Global Power 12V100AH LIFEPO4 - $399! Has anybody actually bought one yet? Torn it down yet?

Thanks for the video. Super informative! Looks like a low cost quality 100ah battery to me. Another year or two and maybe well see some higher capacity and quality batteries at a similar price point/ratio.
 
....I did tear it down in case anyone wanted to see the inside:
Thanks for the teardown vid Bean, you saved me some time! I've been building my own lithium packs for a decade, but the price of these got me to give them a shot. My initial findings are very similar to yours, but mine were even more out of balance.

The BMS's on the better one of mine hits the HVC at about 13.85v and then sends the voltage sky high and bounces back and forth like you have found. Monitoring the sense wires of the BMS shows that one cell pack hits almost 3.9v (ouch) before the HVC stops charging and disconnects. The other cell packs are still under 3.4v at that moment....so there must have been no attempt at top balancing. It is also impossible to charge correctly with a store bought charger, as they are usually either 14.4 or 14.6 volts. I'd like to use one of my multi-bank chargers for these, in series, but the lowest setting on them is 14.1v (gel) and even that is too high for the HVC.

I would not trust charging these in series with a single 48v charger because as soon as one cell hits the HVC it will not only stop charging that whole battery, but all 4 batteries! And we all know charge controllers DON'T LIKE to be disconnected from the battery, especially under a charge load. The back and forth on and off can't be good. For anything. Right now I'm using a power supply set to 13.7v, or homemade chargers made from controllers that have very customizable charge settings (one is the MSB version of your Mr. Pwr.). I will not worry about charging multiples in series until I can get one battery to accept a reasonable charge setting without triggering the HVC. I do want to order more of these batteries for my 48v needs but not unless they can be charged without hassle. The BMS should be a safeguard, NOT a charge controller nanny.

The good news is the cells themselves seem good, and the build quality is good for the price. One of mine will hit about the advertised capacity, but only if I get some cells into the knees on both ends (Overcharging some cells on the charge, and going too low on some cells on the discharge). This is probably why the warranty is only 2 years, as cells don't like to be treated like that.

I am willing to bet many of these problems can be fixed by top balancing and replacing the BMS. That is easier said than done because of the way the pack is assembled. I'm going to attempt it anyway and report back with my findings. There is a chance that junk or used cells were used, in which case balancing may not be possible. I haven't cut open the cell packs yet to see what is inside. It does seem that the cells do settle into a tighter voltage range after some discharge, so my guess is the builder just bought a bunch of these cell packs and hooked them in parallel to balance them at the same voltage, at whatever voltage they were at the time.

TLTR; Probably a great buy for the money for someone who knows how to build (rebuild) a pack and doesn't mind doing some work. The cells seem ok and the case itself is great (sealed but serviceable, they should all be like this!). At this time I would not recommend them to a total lithium neophyte who just wants a plug and play battery...it's not there yet. Wait for the verdict on balancing attempts.

PS. This is maybe the most important part: The Jim seller is a Vet, and he's the best seller I've ever dealt with in my decades of ebay use. He ships faster that you could imagine and he will answer your questions or concerns very quickly. I have no doubt he will stand behind the battery 100%. I'd rather buy from this guy than play around with Ali, for any price.

PPS: I hope he has more in a few weeks. If I can solve the balance problems I will want a few more of the identical batteries for my higher voltage projects. The problem with these china mystery batteries is one might have 80 cylindrical cells, then you order another a month later and they have 4 pouch cells. That is my biggest concern with not buying enough batteries at the same time....
 
Not sure what the appeal is for these kind of batteries other than they are in a tidy package. You can 230ah cells for $110 each and make a 230ah/12v battery pretty easily for about the same price. You could run a pack like that so conservatively, that you could get away with not using a BMS.
 
Not sure what the appeal is for these kind of batteries other than they are in a tidy package. You can 230ah cells for $110 each and make a 230ah/12v battery pretty easily for about the same price. You could run a pack like that so conservatively, that you could get away with not using a BMS.
These are a complete package with bms and case included. Also cylindrical cells don't require compression and as such will probably outlast prismatics. Also US stock, so no long shipping delays, and easier returns/charge backs.
 
These are a complete package with bms and case included. Also cylindrical cells don't require compression and as such will probably outlast prismatics. Also US stock, so no long shipping delays, and easier returns/charge backs.

I am just thinking you could get x4 230ah prismatics and a roll of duct tape for about the same price. Wire them up, run them without a BMS, and just keep the pack between 12.9v and 13.3v. You would still get more power (likely 150+ah). It wouldn't look pretty, but 50% more power is worth thinking about...
 
Rich, makes perfect sense. I concur with Will Prowse, as in his recent video, mentions the use and affordability of these 100ah units. It seems these lifepo4 chemistry, especially when scaling up, is indeed becoming more economical. Add in a bms at a later time and over double the capacity for the a low cost. Unless all one needs is a single unit, scaling up the cells will continue to get more economical going forward.
 
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They are less than $300 right now, so once you add a bms and case to your system their pretty hard to beat price wise. I recently built a 20kwh battery out of prismatics, once I added a bms/bus bars and enclosure, my time would have to be worth nothing to come out ahead vs these.
 
I am just thinking you could get x4 230ah prismatics and a roll of duct tape for about the same price. Wire them up, run them without a BMS, and just keep the pack between 12.9v and 13.3v. You would still get more power (likely 150+ah). It wouldn't look pretty, but 50% more power is worth thinking about...
It depends on the application, for something like an RV a professionally packaged battery would likely be viewed much more positively by potential buyers when it comes time to sell the RV, or to an insurance adjuster should something happen to the RV.
 
I simply don’t trust myself or the battery without a bms. So easy for one cell to go above or below where it should. I don’t need that kind of stress in my life.

While I’ve built plenty of prismatic packs people I run into don’t typically want an exposed pack held together with duct tape.

It’s worth it in larger packs to figure out a structure but $300 simply can’t be beat diy. I think having a solid case and terminals is under rated. Just my opinion. I believe there is a use case for both.

For anyone interested. It does appear the built in bms has a balancing feature. As observed from my clamp meter on a sense lead. I’ll be doing a longer term test to see how long it will take to balance itself out.

I’ve also been told the mosfets are “gen 4” type that are 30-40% more efficient. Gen 4 is definitely a thing, don’t know how to verify the claim other than they sure don’t seem to put off much heat!
 
Hey. I'm still all about these cheap batteries, pretty sweet deal for just over $300 each if you buy 4+ shipped. Even just one at $299 + tax is better than building at 12v 100ah yourself. Time is definitely a value one has to factor into these things. Lots of people would rather do something else than build batteries but still want reliable lifepo4 storage at a good price.
 
I simply don’t trust myself or the battery without a bms. So easy for one cell to go above or below where it should. I don’t need that kind of stress in my life.

While I’ve built plenty of prismatic packs people I run into don’t typically want an exposed pack held together with duct tape.

It’s worth it in larger packs to figure out a structure but $300 simply can’t be beat diy. I think having a solid case and terminals is under rated. Just my opinion. I believe there is a use case for both.

For anyone interested. It does appear the built in bms has a balancing feature. As observed from my clamp meter on a sense lead. I’ll be doing a longer term test to see how long it will take to balance itself out.

I’ve also been told the mosfets are “gen 4” type that are 30-40% more efficient. Gen 4 is definitely a thing, don’t know how to verify the claim other than they sure don’t seem to put off much heat!
What triggers the balancing feature? Once the BMS was done it didn't seem to take any more current. We seem to have dual threads on this battery. https://diysolarforum.com/threads/i...-i-post-a-video-here.30467/page-5#post-382979
As I mentioned on your youtube channel, I'm only getting about 70 ah out of mine, & I'm suspecting it's due to lack of balancing.

2021-11-28 14.12.54.jpg
 
What triggers the balancing feature? Once the BMS was done it didn't seem to take any more current. We seem to have dual threads on this battery. https://diysolarforum.com/threads/i...-i-post-a-video-here.30467/page-5#post-382979
As I mentioned on your youtube channel, I'm only getting about 70 ah out of mine, & I'm suspecting it's due to lack of balancing.

View attachment 73789
It’s hard to see but I believe the balancer is kicking in when a cell hits 3.6/3.65v. I’ve been gathering data on it this weekend and will report back.
 
You can 230ah cells for $110 each and make a 230ah/12v battery pretty easily for about the same price.
I snowbird around following the weather and don't know where I'll be when the slow boat arrives in X months. I definitely don't want to pay to have my remailer to [re]ship them to wherever I happen to be.

Additionally, I only need 100Ah of capacity. I am typically a DIY guy with most things but for those reasons I bought a drop-in from Rebel. Very happy with it.
 
No. I do not have the the tools to do it but I know fore of them power every thing all night where ten led acid deep cycles could not. Plus they still have power to spare in the morning.
 
They were selling on ebay for $584 for two...I nearly pulled the trigger. Some users were having trouble with bms trip at 14.6V so I paused...the sale price ended. I ordered plain eve cells instead with a overkill bms.

Anxious to see how they worked out - glad they're doing well. I liked the stats on the seller. (y)
 
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