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I’m down in warmer Yuma now, no further issues. The only other change I’ve made is that the BMS is ratcheting down the battery capacity when I don’t charge to 100% every day. I did reset that. I’m currently charging to 13.7v on the Victron with a two hour absorb time. The battery box I...

Now they are diverging again, another 15-20 minutes. No load, and no charging as it’s night time. I’m guessing the bms is bad?

They seemed to pop back into relative balance fairly quickly. 3.19 and 3.3. They are both still oscillating, but slowly moving back to equalization.

They started diverging again after 15 minutes under a mild load. Load was switched off before disconnect. At 20 minutes they may have ‘stabilized at 2.37 and 4.12. They now appear to be leveling again, with no load.

Cells were roughly at 2.6v and 4.0v. They are now at roughly 2.9 and 3.6 after a half hour. The high cell has been one consistently but modestly out of balance, ~60 milivolts.

Strangely, I have one cell triggering an under voltage disconnect and another triggering an over voltage disconnect. I presume the error has something to do with the average between the two cells, but that’s pretty vague. The bms is a jbd, 4 cell 280ah battery about 1.5 years old. I...

One way to think about the comparison is that lead acid only gives you 50% of capacity while your application is estimated at only using 80%. In addition note that heat is also damaging to LFP. Lastly do note that charging up to 100% on occasion, say in advance of a Hurricane, would be...

There are possible issues with two batteries on a single controller. The issue I’m aware of is that both batteries need to be relatively similar in capacity, age etc. Matched and balanced, if you will. This would apply to both a series and parallel connection between the two batteries. This...

As I understand it the Growatt is popular with 48v residential folks. I too am looking at 24v, as an upgrade on my current system. I’m not convinced of the benefits of a combined inverter/charger over a separate component system. Following.

You could always lower the settings on the BMS, if possible, to a slightly more conservative setting. It is preferred to have this done by the charger by most. At the very least the BMS can act as training wheels while you figure out what is going on. In a similar regard lower amps will be...

Ask/specify packaging method. As with big corporations in America they may well be slow to figure stuff out.

A reasonable guess would be no more than the discharge current. Also, why would you need to use that connection rather than just charge separately?

Check out Will Prowse’s YouTube reviews, prices have gotten cheaper. If you controllers will do 24v and you can series up your panels the 24v server rack batteries might be the best. 5kwh for $1500 and up.

Buy a used cell.

I don’t know if there are circuit breakers that can work as a switch, there are however circuit breakers that can’t, failing before too long.

Controlling all conditions in a precise test is difficult. Easiest way to tell is to run the test again at the controlled temp you had previously.

I’m confused as to what you are looking for. Converting any tool box to an electrical box is a good strategy. I’m curious as to all the connectors used in your first two photos.

Also, LiFePo4 does have a much better charge curve for generator based recharging.

Just a general comment. Although starting to convert to LiFePo4 is a good idea doing so incrementally might be wise as prices may drop, there is a learning curve, and you may have additional life in the lead acid perfect for bad weather use. Make sure you purchase from a known good vendor...

I received my cells, from another company, on a second tracking number from that originally provided. I had no advance notice of delivery.

It’s surprising it took as long as it did.

It is already the case that OTS products are a better choice for the typical small user such as the RV market. The best future value may well be in a lowered price for sub grade cells with fewer suckers purchasing.

I did not need to do a top balance with my Luyuang cells.

That absorb time issue at lower charge voltage cut offs led to me use the default Victron profile, charge to 14.2, 3.55 plus two hours of absorb at that same voltage. My use is such that I will only occasionally use anything near full capacity. As with lead acid that infrequent deep discharge...

I believe you will find other negative reports on this forum. I would request a partial refund.

The shipping foam for the cells can be used for both temperature and shock insulation!

Pretty much the same deal if it takes a couple of months to balance.

I bought good quality cells and did not need to top balance. Ditto on the storage.

One thing I’ve noticed is an apparent substantial drop off in solar charging at lower voltages. I haven’t measured it, but it seems I drop out of bulk way to early if I charge to 13.9 as opposed to 14.2.

I’d be comfortable avoiding the BMS for a short peak, but not for a typical heavy use of 2000 watt loads. This is not my area of expertise, but it sounds like a super capacitor might be the ticket. I’ve no idea how user friendly that tech has become. Another question - is it possible to...

Bad from the get go and bad over time are usually different things with electronics, but not necessarily.

The charge controller and the BMS are redundant. The charge controller is primary. A BMS can track your load and similar. I don’t know if there is any benefit integrating that with a controller. The Victron suite of products provides that functional integration, but that’s over my budget.

Solved, reset on first load.

I would suspect that as the batteries get older the likelihood of divergence would go up.

You could try the 3p4s configuration to get going if you are confident of the quality of your cells. In any case, you will want to check individual cells periodically. Upgrading your BMS at a later date as needed and budget allows seems like an ok plan to me.