Modern Vespa

My wonderful LX 150 lost power a couple of days ago because the key was left in the bike and turned on, so the lights were on.
Cue a buddy hooking up a battery charger. Instead of trickle, he put it on "Start" and we walked away for an hour.
Don't do that.
Came back to heavy plastic melting smell and water leaking out of battery. Battery was so warped from the heat that we could not get it out.

Finally had to do a bit of sawing. We were lucky the battery did not explode and catch the bike on fire, which would have toasted an RV and a garage.

Edit to add: I tried to post this as a comment, but I don't know where it went. I believe what I wiped up was condensation. There was a lot of steam coming out from around the battery (it was cold and humid); the towel I used didn't have any damage, and the paint didn't have any damage.

I don't know what the amps on the battery charger were; I do know that we should have checked my friend's settings instead of trusting him to have it on trickle.

You were lucky! What leaked out of the battery is not water but acid. Use tons of water and rinse everything around...

I have only used the trickle charger. Thanks for your info on what to
avoid.

Bob Copeland

please clarify how many amps you were pumping into that battery on "charge" setting?

never use a standard car battery charger or any charger over 2 amp rating on small motorcycle or atv or kids power wheeler.

Wash the whole area down with baking soda and water. Better safe than sorry.

On my charger "Start" is 55 amps. No wonder the battery melted.

So, once the new battery was installed (a $91 lesson learned and it was newly installed last fall) the original problem was diagnosed as a carburetor problem.

Dissolve a little bicarbonate of soda to neutralise the acid.

As I posted in the edit, I believe it was condensation, not battery acid. When we finally managed to get it out, the plastic covering was intact.
It was fairly cool and humid when this happened. There was no damage to the paint, the towel or the asphalt - now or when this happened 4 days ago.

Maybe the battery just vented, rather than leaked. Most of what comes out of the vent would be steam. I'd still wash down the surrounding area with a baking soda solution, just to be on the safe side.

Frankly, I'd never use a 'dumb' charger on any bike battery if I wasn't around to keep an eye on it. Usually if I'm not in a hurry, I'll put on one of the battery tenders over night. Most will only do 1 or 2 amps, so no worries about overheating, and they'll shut themselves off when peak voltage is reached. Might get away with a car charger set to 2 amps, if it has that setting, but you'd still need to keep an eye on it. Even 5 amps is probably too much.