Battery overcharging?

[Jdean89]

For some reason the battery on my corsa is running at 18+volts and by the looks of things is causing the battery to leak (theres a white powdery layer all over the gearbox, i'm guessing its battery acid?) Annoying thing is, it's a new battery and a new alternator (about a month or two old)... any ideas anyone? seems like problem after problem with 15 year old cars lol

thanks

[smoothsebsta]

never heard of that before, possibly dodgy battery? ? and that white stuff is battery acid.

[Jdean89]

yea i figured it was battery acid :/ i've got 2 batteries and both of them do it.. one of them doesnt even start the car anymore and yet they both seem to be holding charge (both at 12.6)

[Octane2097]

just a thought u havnt fitted the wrong altenator for your car have you?
theres 2 types 55a and 70a, most petrols take a 55a and the diesels go for 70a (needs higher power for a diesel engine)

check what engine ur car is and then check on tinternet make sure its right alternator for it
wen your engine is off should see around 12volts give or take 10 should be fine
when your engines running tho it may jump up to about 16ish depending.

[scotty cav turbo]

Fook, be carefull with the alternator charging at 18v, as your battery could explode!! Even tho its a new alternator it sounds like the regulator is knackered and is over charging big style.