[jlanman]

I have 2 Cells in a 45 cell pack at approximately 1.5 volts. The rest are at 3+ as they should be. I prefer not to invest in two new cells. What are my alternatives?? Is it possible they can be rejuvenated? If so how? I assume I can just by pass them in the string and accept the loss of range and power. I believe the only issue might be the charger program which is obviously now for 45 cells.

 

[Moltenmetal]

Your options are to bypass them or to replace them- that's it.

Bypassing them will mean a minor loss in power and range, and a little work to reprogram your charger. Or not- you can simply leave your charger set the way it is and rely on the BMS to shut down the charger at the end of charge. Combining that with a total pack voltage shutdown (an alarm via your amp-hour meter is one way to do this but there are many others) will mean that you won't be relying on the BMS to save you every time. You'll no longer get active top balancing of the pack if you go this route, but in my experience it hasn't made much of a difference. There's a downside to trying to squeeze the last few Ah into the pack during that final low current balancing phase anyway- holding the pack at high voltage for longer periods of time than necessary does result in additional pack degradation.

My own ElCon charger has multiple charging programs onboard that you can select by pressing in a switch under the label during the power on cycle. Mine is only a few years newer than yours. ElCon has good documentation on their website. The charger comes with a label which explains what each program is set up for. My pack has 32 cells but my charger can be set up for quite a wide range of cell totals.