"mike" wrote

Ordinarily, the acid doesn't evaporate...just the water. Conventional
wisdom is, "never add acid to a battery."
I'd remove them. Add water. Wait a few days for things to
diffuse around before trying to recharge.

Chance of recovery is slim and none, but the cost of the experiment
is low.

I'd replace the cranking battery and make sure the thing runs.
Remove the other two, verify that you won't blow up all the lights
because of the way the charging circuit is implemented.
Sometimes, you can put a jumper from the cranking battery
to the rest of the system. Don't just short one of the isolation
diodes, hook the cathode sides together.
And verify what you're doing so you don't blow stuff up.
They're not always wired the way you'd think reasonable.

Don't try to jump start it with the bad batteries.
You never know what the open-circuit alternator
voltage will do to the electronics the instant you remove
the jumper cables.

And don't try to run the microwave from an inverter when
using just the cranking battery. Wiring is often sized by
the charge current, not the maximum discharge current.

Negotiate the price based on whether you replace the other two.

There was a jumper from the starter battery to the first battery of two, in
what I consider would have been "house power" battery pair. The second
battery has about four leads to each terminal, the third, only two.

This was an old family friend. Three years ago, he came to live with us
when they diagnosed him as terminal. He lived with us a year to the day of
move in. No one has taken the initiative to dispose of the motor home,
probably for sentimental reasons, and I did not say a thing. Then, finally,
they want to get rid of it, and guess who gets to take care of it? Yep.

No biggy, as he was a dear friend, and quite a gentleman and character.

Time to move on.

Think I'm going to take an older but good battery from my boat, just to get
it running, and sell it as is, and get a new battery for the boat. I'll
have a friend of mine look at it, and if it's solid electrically, I'll
replace the other two. It's easier to sell when it's running right.

It's a Bounder, and if I didn't have so much going on, I'd keep it and bring
it up to snuff. I like motor homes, it's just that whenever you want to go
somewhere, there's always something that has rotted, or the mice ate, or
that shorted, or failed, or, or, or .......... I loved the lifestyle and
traveling in them, they are just a LOT of work. I had a 34' diesel pusher.

I don't know if I'd ever have another even if I hit the Lotto. I like
Kauai, Alice Springs, and San Jose Cabo too much. And there's no getting
greasy or towed in.

Thanks for the help.

Steve