Generator battery

[73shark]

Doesn't the alternator charge the house batteries anymore?

[Protagonist]

Originally Posted by 73shark

Doesn't the alternator charge the house batteries anymore?

It should, if the BIM allows it to happen. I had my Interstate at the dealer for some repairs, and they left the house systems energized while it was parked. The house system got depleted all the way down to 9.9 volts. Naturally, that caused the BIM to separate the house and chassis systems.

I was able to plug into shore power for about half an hour and got the house batteries up to about 12.3v (65% charge) before I had to head back home to beat some nasty weather. That was still too low for the BIM to re-integrate the house and chassis systems, and so no charging at all from the alternator on the drive home, despite being on the road for over an hour.

I've been using the Interstate as my daily driver every day since then, and the alternator still isn't charging the house batteries. But the good news is, my solar panel is charging them, albeit slowly. The rate of charge has gone up about 5% each cloudy day, and 10% each sunny say, and stands at about 90% as of yesterday.

[73shark]

Sounds like there's a problem w/ the BIM. On a cloudy day, my house batteries dropped to 12.3 and as soon as the engine was running, the charging voltage applied to the house batteries.

[Protagonist]

Originally Posted by 73shark

Sounds like there's a problem w/ the BIM.

I don't doubt it. House batteries at 9.9 volts is below 0% charge! I'm surprised they're charging at all. And yes, I had some unkind words to say to the dealer's service department for letting the batteries get that low while the vehicle was in their care…

[73shark]

According to my dealer, the house batteries are non-prorated warrantied under the AS 3-year warranty. Might have them tested to make sure that excursion to 9.9V didn't damage them. From what I've read on the 'net, AGMs have to be tested differently than a standard lead-acid battery.