Plecoptera
New Member
- Joined
- Mar 23, 2021
- Messages
- 47
I spent the coin to add four AmpereTime LiFePO 12V100Ah batteries to my RV system. Previously I always used AGM, and never ran a battery bank.
After much reading, including Victron's pub on Wiring Everything, I arranged the four LFPs in a parallel bank after fully charging individually using my Victron charger. Victron says they all charge to 14.2V without problem. For the bank I was careful on cabling, 4AWG, same length, same terminals, what Victron calls a "Halfway" bank of (+ - 1&2), (+ - 3&4), and then (+ 2&4), (- 1&3).
One battery rests at 13.5V (#4)
Two batteries rest at 13.4V (#3 & #2)
One battery rests at 13.38V (#1)
I can hook up the bank to my panels(4 x 100W in series ~ 80V) via a Victron 100 30 MPPT, and watch it all on BlueTooth, and everything works just peachy. I can charge while using an Inverter, just peachy. The bank all rises to 14.2V, before it heads to storage mode. Then, when I disconnect, let the BMS do its thing, I come back to 13.5V, 13.4V, 13.4V, 13.38V.
I have never watched my batteries at anything like this level of detail, so I don't know if variation of ~0.1V is normal or not. It seems like the BMS should eventually get everything to 13.4V, since that would be average, but that is not what I see.
Is this normal?
Question #2
Would I be better off putting my two 13.4V at #1 & #4, and 13.5V and 13.38V at #2 & #3?
Question #3
My cables from my MPPT are + #1, - #4. My cables from my Inverter are + #3, - #2). So I charge first on the outer two batteries, draw first from the inner two batteries. Is this approximately intelligent?
After much reading, including Victron's pub on Wiring Everything, I arranged the four LFPs in a parallel bank after fully charging individually using my Victron charger. Victron says they all charge to 14.2V without problem. For the bank I was careful on cabling, 4AWG, same length, same terminals, what Victron calls a "Halfway" bank of (+ - 1&2), (+ - 3&4), and then (+ 2&4), (- 1&3).
One battery rests at 13.5V (#4)
Two batteries rest at 13.4V (#3 & #2)
One battery rests at 13.38V (#1)
I can hook up the bank to my panels(4 x 100W in series ~ 80V) via a Victron 100 30 MPPT, and watch it all on BlueTooth, and everything works just peachy. I can charge while using an Inverter, just peachy. The bank all rises to 14.2V, before it heads to storage mode. Then, when I disconnect, let the BMS do its thing, I come back to 13.5V, 13.4V, 13.4V, 13.38V.
I have never watched my batteries at anything like this level of detail, so I don't know if variation of ~0.1V is normal or not. It seems like the BMS should eventually get everything to 13.4V, since that would be average, but that is not what I see.
Is this normal?
Question #2
Would I be better off putting my two 13.4V at #1 & #4, and 13.5V and 13.38V at #2 & #3?
Question #3
My cables from my MPPT are + #1, - #4. My cables from my Inverter are + #3, - #2). So I charge first on the outer two batteries, draw first from the inner two batteries. Is this approximately intelligent?
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