What causes battery acid to leak from a sealed battery?

[Zed Sqd]

Problem: Got the van (Toyota 2.4D 4x2 Hilux, 2L engine) with battery acid leaking out of both poles of the battery (the one that has to be topped up with water now and then). There was heavy corrosion of the terminals, wire and battery stand where the acid contacted.

So I say "ok", I'll just replace it if it comes to that.

Attempts to fix the problem: Checked the charging of the alternator and even replaced the old battery with a brand new, maintenance-free Bosch battery. Even the battery temperature felt normal after running the van.

Afgter that, the acid is still leaking, but now from the positive pole. Thinking this was a defective, new battery, I replaced it with another new battery. Same ting happening just after a couple of days!!!

Any idea on what the fudge goin on here?

[VexXx Dogg]

alternator damaged, possibly overcharging battery,
Get a second opinion on the alternator

[Zed Sqd]

Well the charging of the alternator was done at two places at the suspicion of overcharging, and it seems to be fine.

Hmmmmm.

[VexXx Dogg]

if not overcharging, check the rectifier circuit.
it could be damaged diodes that sending a partial AC current to the battery.

[Zed Sqd]

Will do that and update...Thanks!

[krack korn]

Mechanical force or tension on the poles caused by the cabling weight, excess force when tightening, loose battery etc

Will cause the pole to become loose of the sealant that surrounds it and the acid will come through.

clean thoroughly and try to seal with a flexible sealant, silicone or other. Cables should be suported or fixed close to the battery so as not to transmit movement or vibration. Just look at a new oem install and u will get the idea.

overcharging will cause the pressure to come out the valves, "sealed" batteries are not realy sealed but must have a pressure release mechanism for each cell, the pole is not the point of release.

[vanbella]

cells breaking down and acid leaking out

[toybago]

battery lugs may have residue from previous battery, clean them thoroughly or change them.

also you can purchase the felt washer type things that prevent corrosion from forming at your terminals, these work fabulous for me in the past, along with brass coated lugs....

[DSM_05]

defective battery that actually has a leak?

[JETTA1000]

this is so simple you need to replace the lugs its either cooper
or has cooper in it replace lugs and your problem is gone saw this on a
hyundai cooper lugs or cooper alloy remember you cant have any kind of metal
that has better conductance properties than lead
it interferes with the chemical reaction in the battery

[JETTA1000]

this is so simple you need to replace the lugs its either cooper
or has cooper in it replace lugs and your problem is gone saw this on a
hyundai cooper lugs or cooper alloy remember you cant have any kind of metal
that has better conductance properties than lead
it interferes with the chemical reaction in the battery