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Old 12-07-2018, 06:49 PM   #91
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Year: 1986
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Originally Posted by Solardad View Post
On the number of cells being monitored by a single BMS how well does that work or maybe I should ask how does it work? Does it take the average of the two cells that are connected to the BMS wire? I take it you could hook up as many as you want but would lose the balance accuracy and the effectiveness of the BMS in being able to balance being limited by the charge limit?

Also what are the connectors that you are using between the BMS wire and Volt BMS wire, it appears to be a crimp connector.
Based on your questions, it sounds like your intuitive understanding is spot on. The optimum setup is for the BMS to monitor single cells, as in a 12S BMS would monitor a single 12S battery pack. As you add cells in parallel, I would say that you lose "visibility" on the individual cells.

In my research and in my experience with these Volt batteries, they really do tend to stay in balance. For me the BMS's serve primarily as an insurance policy and as an easy way to check the batteries. I have seen dudes on the YT who run these batts with NO BMS and just take regular cell voltage readings with a multimeter to make sure they don't stray.

I have joked about the quality of "Chinese BMSs sold on a Russian website", and as I mentioned, I did recently order a spare... However, my battery pack with 4 of these BMSs has been in service for 7 months with zero issues.

As for BMS wiring, I used Posi-Lock wire splices. For my setup with eight 12S batteries monitored by four BMSs, there were 52 BMS splices, and the Posi connectors offered easy and secure connections. They are not sexy but they are very reliable...

Are you documenting you own experience with these batteries? If not please consider doing so. In my opinion, Lithium is the ONLY WAY TO GO WITH BATTERIES... Lead acid to Lithium is like horses to cars...
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Old 12-07-2018, 07:25 PM   #92
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Thanks for the info.

Yes.. I have seen a few tubers and their expirence, Mark Osbore is one I believe and he has an impressive setup mixing Leaf and Volt packs successfully for over a year now I believe.

I agree that this BMS could be considered cheap insurance. I was able to purchase two packs from 2011s for a total of 2900 including shipping. One pack is broken down into 4kw packs, two 12 series modules, heavy but I liked the idea of not messing with the cover too much protecting the individual cells. The other I just started but I am racing the weather to get my array up and running so my battery bank is taking a back seat at the moment.

Your experience convinciced me to go ahead and order some more units so i have them on hand when I do the final setup of the two pack.

No documentation at this point but maybe when I get into tearing down the 2nd pack I’ll post a thread for others to follow.

Btw the posi-twist product seems perfect. I was thinking of a solder connector but I like the idea of being able to easily undo a connection if needed.
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Old 05-14-2019, 11:09 AM   #93
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This whole thread has been fascinating - I never considered going with lithium batteries for my future skoolie before, but now it really seems like the only logical choice for the full-scale off-grid potential I'm aiming for. My only concern at this point would be replacement - swapping out an acid battery that goes bad is no biggie, they're available at any auto parts shop, but how easy is it to find single Lithium cells if you need to? And to access the ones that need replacing? Or is that not even really a concern for a solid-state battery like these?
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