MEP803a Battery Charging Issue

[Johncar48]

Yes Sir, the battery closest to the charge alternator went bad and so did the alternator but other battery was fine so only had to replace one. They’re less than a year old.

 

[Johncar48]

Yes Sir, the battery closest to the charge alternator went bad and so did the alternator but other battery was fine so only had to replace one. They’re less than a year old.

I am curious though. The battery closest to the recharge alternator reads 12.7 volts while the other reads 14.8. Is this normal?

 

[Digger556]

I am curious though. The battery closest to the recharge alternator reads 12.7 volts while the other reads 14.8. Is this normal?

It reads 12.7v and 14.8v when charging?

Yes, that is possible if the batteries are out of balance. (Different states of charge) It's also potentially damaging to the batteries because the alternator's regulator only understands that it needs to output 28.8V, and if one batt has a low state of charge and is sitting at 12.7V, the other will be at 16.1V. Too much voltage for a single batt.

Best to charge the batts individually using a 12v charger to get them to the same SoC. This is why batts should be replaced in sets.