Battery suddenly boiling like it's gonna blow..

[Ultra2extreme]

Hi all wanted a bit of help from anyone with deeper knowledge of transits as I've only worked in depth on cars and never had much in the way of electrical faults. So I've got a beater of a transit mk7 07 plate 2.5 (I think never really checked.) And its been sat a while as was bought for a house move. Anyway long story short I put a new batt in it about 8 months back and started it approx once a month always started first time. Anyway prob missed a few months, went away for a weeks hol. Got back had some errands to run went to start and it's FLAT I mean no life dead.

Tried for a few hours to jump it but just couldn't get the juice across. Crap leads etc. So took out batt n put it on a charger overnight. Next day charging dropped to about 2a so figured it was topped off (its a 12v 80ah 680a batt) popped it in van started right up. Hooray.

Except the instrument cluster is now mental, comes on n off at will, seemingly in between gear changes ie in neutral. Then today even more worrying I drive it up hill under load and you can hear the battery fizzing and boiling and peeing out electrolyte all over.

Wth is going on? I don't wanna fork out 100 notes on another batt if somehow it's the van killing it? Is there any precedent out there?

Tia lads cheers

[metalworker0]

Must be over charging , there may be a fault with the alternator that is causing this .
measure voltage ...should be 14.75 max engine running ......then after a while when its got the battery topped up ..it should drop down to below 13.75
Perform this test first .
Make sure terminals are connected the right way around .
Don't know if its possible with duel batteries to connect them in such away that they equal 24 volts

all the best.mark

[knobby1]

So I've got a beater of a transit mk7 07 plate 2.5 (I think never really checked.)
Tried for a few hours to jump it but just couldn't get the juice across. Crap leads etc. So took out batt n put it on a charger overnight. Next day charging dropped to about 2a so figured it was topped off (its a 12v 80ah 680a batt) popped it in van started right up. Hooray.

Except the instrument cluster is now mental, comes on n off at will, seemingly in between gear changes ie in neutral. Then today even more worrying I drive it up hill under load and you can hear the battery fizzing and boiling and peeing out electrolyte all over.

Wth is going on? I don't wanna fork out 100 notes on another batt if somehow it's the van killing it? Is there any precedent out there?

Tia lads cheers

There's no such animal as a 2.5L Mk7, will be 2.2, 2.3, 2.4 or 3.2. How long have you owned it.??

What voltage are you getting across the battery at idle..?? Should be ~14.4v-ish, if more, your reg/rec is done for and the battery will be toast. Standing voltage should be ~12.6v.

Do not drive the vehicle with the battery boiling or fizzing, there's a real risk of a battery explosion...the results aren't usually nice.

Lord Knobrot

[Altransit]

If it's a 2.4 or 3.2, it should have two batteries