Testing cheap..er Chinese batteries

[Whatta Life]

I build custom lithium packs for different applications. In the shop right now, probably 1000kw of lithium. Small cells, medium cells, large cells, small modules and large modules. They consist of Lifepo4, NMC, and Lithium Titanate. I have 2 boats that I threw together lithium batteries for. But some of them are your typical blue aluminum cells, with BMS's. Was getting around to building enclosures to protect them from the elements and I wanted 2 of the banks to have bigger batteries. Enjoy watching Will Prowse YouTube video's and decided maybe to use a premade battery for house and outboard banks on one of the boats. Ordered a Chin's battery off of Amazon($379) to check out, Will reviewed them well so started there. Order battery, 2 weeks later, here it is. Didn't have a lot of free time so threw it on a lead charger for a few hours and then came back for a quick test.

It was not fully charged, but close. This is their 100ah battery. 100a continuous discharge, 300a for 5 sec. Inverter started @ 85a, .85c for 5 minutes, all good. Bumped up to 115a for 1 minute, and then back to 85a, no problems. Put a temp sensor on terminals after 15 minutes, ambient 85, terminals 110. Pushing it at .85c for that long, I was happy with results. Battery was down to 12.3v so stopped for tonight. It is on the charger now and tomorrow it will be high amp tested. So far, so good.

[Whatta Life]

https://photos.google.com/photo/AF1Q...-crR8IyCf9QH5G

[grantmc]

Unfortunately your url to the photos gives a 404 error.
So perhaps not public, but definitely doesn't work.

[Wotname]

The link asks me a for google account so I didn't bother progressing past that point....

[Whatta Life]

This is better

[robgsailor]

This guy has done extensive test on Chinese lithium batteries

https://youtu.be/xBonGQe363g

Worth checking out to compare your results.

[Whatta Life]

Put the battery on a load tester. BMS is rated 300a for 5 sec. . Tested at 350a for 10 seconds. BMS held without shutting off. Will had capacity tested them and they were over 100% rated capacity. Is would cost more to buy the individual parts and assemble one, not to mention all of the time. These drop ins have gotten much better in the last few years. I remember testing others that started smoking under load. Tore them apart, bad connections, small tabs connecting cells, no insulation, cells that had different internal resistance, etc. Time will tell how well these newer version will do, but it might take a lot of years to find out.