batteries die, help plz

[Brickhouse]

Hope someone can assist here. It's been over a year and a half, 5 mechs (including Ford), and still going nowhere.

The batteries die. Secondary note, after a while, the tops of the batteries around the fill covers get wet. 3 months ago, mech said both batteries had bad cells, and we replaced them. They checked for power draws, nothing, checked charging, good.

This morning the old symptoms are back.

A few years ago, the frontend and some engine items had to be replaced. I think the Alt was one of the items replaced. The shop used an excursion for many parts, and may have used the excursions alt. I just went down to see if I could determine the part number or type Alt is on there. I was looking for the two or four hole markings in the case. There are none. The case only has open wide slots.

Question, could my condition be that the wrong Alt is installed? How about the voltage reg? The truck should have had the emergency type higher amp alt from the Eclipse conversion package. I'm debating on getting one of the “Extreme Duty” Dual Rectifier Alternators in about a 250amp.

Ran auto enginuity multiple times, and see no codes or problems. CPS replaced, all looks good.
No SES light
WTS light works, so indicating the PCM is running.
tach movement while cranking, so CPS is working.
Everything looks good, but the batteries just get to low over a period of time, and will not have enough juice to get it going. Add a jump booster, and starts right up.


Any thoughts please?
Thanks

[brockallentaylor]

Surely your Alt is bad, causing voltage spikes and under-charging at times. Hook up an amp meter and verify that you have no power draw over 500ma with the key off and wait for it to enter battery saver mode (20min IIRC). Your batteries are leaking fluid because they are being discharged too far so when you get a jump they have to take a really harsh fast charge from the alternator for the next 20min or so which boils the battery acid causing some leakage. It is pretty normal and will happen less if the batteries stay topped up.

[Brickhouse]

Everything I could think of was pointing to the Alt. Thanks, will check it out. Guess ordering that G6 upgrade yestorday was a good thing.