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I have a converted Ford Ranger using Forty-Four 185AH Lithium Phosphate batteries that are 6+ years old. The original Elcon charger died and I replaced it with a Zivan NG3. The original conversion included a MiniBMS which I left installed but not connected to the charger.


I charged the pack which topped out at about 144 volts as expected based on the old Elcon. I got alarms at 8 miles and had 137-138 volts. Past experience was 30+ miles to a "play it safe" recharge. I had the vehicle towed and started trouble shooting. I found an average cell voltage of 3.1 or so with one at 2.95. All others were over 3. One board LED was out; but, cell voltage was over 3.


Research indicates that I should not have gotten an alarm, which might ultimately result in an BMS initiated system shut down, until 117 volts. It also seems to indicate the going to about 120 volts will not harm the pack.


Do I just have a bad case of range anxiety and should disconnect the alarm??
Man, your finishing voltage while on end of charge should be 154 volts.

Cells should be 3.500 volts just before the charger turns off.

That's ALL cells.

Have you done a TOP OFF individual cell charge AFTER the bulk charge and noted AH in to achieve 3.500 volts. That's one cell at a time.

Have you done a DISCHARGE load test with a resistor drawing 20-75 amps until a discharging voltage of EACH cell of 2.75 volts and note the -AH?

That's what's needed.

And why aren't you using your BMS????

Oh, "And over 3 volts," doesn't mean much. Resting voltage should be in the 3.2 volt range. 3.0 volts is fine after many miles, but 2.8 volts under load is pretty much dead.
 
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