Battery High Tide

[mvalenti]

Last season (Fall), I made a mistake and boiled my battery on the charger. The other day I attempted to resurrect it. added D/I water, and let it sit overnight, topped it off in the am and hooked up the trickle charger, fill caps removed and still installed in the bike, allowed to charge over night. The next day, with caps off still, I tried to turn it over. To my surprise, the water in a few of the cell actually rose, and quickly! What would cause this?

TIA!

[Steve]

What would cause that?

A bad battery.

You said you boiled it on the charger.

What you really meant was "you KILLED the battery".

Just bite the bullet, go get a new battery.

Get an AGM battery, you can't boil it dry.

.

[GSCafe]

It is possible to resurrect a battery but it takes a really, long time. Maybe 3 months. I did a little research and was gonna try it but I ended up getting a lithium-iron battery and never got around to it since the old ones won't fit with the new mods. If I remember, the trick is getting the one pole of the battery to desulphanate back to the water through a long period of low trickle charge.

[mvalenti]

my goal wasnt to cheap out, it was just an experiment. My result was a quick and dramatic rise in water levels in a few cells. It raised the question why....

[Brendan W]

At a guess some plates got distorted and are shorting out boiling the water, the bubbles local to the short are raising the level ?

[GSCafe]

I'm guessing that the difference is that some of the cells are still stone dead at this point and you are making a high amperage demand on the few that aren't totally dead. (Hence the water rise) If you trickle-charge for a while and then measure, there is probably less than 12V corresponding roughly to what proportion of the cells are toast. Trickle it for a lot longer and you might revive more cells and see less water rise across more cells.

[mvalenti]

all good points, but what is actually displacing the water during cranking?

[GSCafe]

I think that it is heating up the water. That is not displacement. That would cause the water to expand. (thermal expansion)

[eil]

The electrolyte "rose" because the charging process created hydrogen gas bubbles on the plates. If you shake/tap the battery, the bubbles will dislodge and rise, causing the levels will drop a bit.

[GSCafe]

The electrolyte "rose" because the charging process created hydrogen gas bubbles on the plates. If you shake/tap the battery, the bubbles will dislodge and rise, causing the levels will drop a bit.

Unless I'm mistaken, I think he is saying the level rose quickly during cranking not during charging. That may still be bubbles as someone already pointed out. Dang, I might have to dig up that old battery later and see what results I get.

[eil]

The wording is ambiguous... it's impossible for the electrolyte level to go up on its own during cranking (unless there is some really wacky and unusual structural failure going on) so I took it to mean during charging.

[mvalenti]

https://www.dropbox.com/s/tfqxkr3pqw8mwoz/2015-03-18%2020.09.350.mp4?dl=0

Almost 20F here... k new she wouldn't turn over but gave it a shot. Keyed on anx hit s tarter. ...

[GSCafe]

81F it was here! I found my old battery and hooked it up to the trickle charger. If the flashing green light means what I think it does, I might have to trick the trickle charger for this experiment by putting a good battery in parallel.

[GSCafe]

Okay, just about ready for the follow up on this. I had two dead batteries and one good on on hand. I connected the trickle charger directly to each of the dead batteries and they didn't want to charge. I jumpered the good battery in parallel and reattached the trickle charger. That worked as Thevenin's equivalent voltage says that it would be seen as one 12V capable of twice the amp hours. (roughly...these dead batteries differ in cranking amps ratings) After charging it that way for a while. I was able to switch to connecting the charger to the formerly dead battery for the final charging. One gives me a steady green light on the charger and measures 12.80V. The other is still charging and currently measures 13.20V. Tomorrow, I will take the one that belongs to the FZ1 and see if it will now crank that bike.

[OldVet66]

When you boil out a battery the acid is still there. I would imagine when it goes back in solution with the distilled water it will have some additional volume. If the battery is just filled with distilled water and let sit, sometimes it will come back with a charge. It happened when my battery boiled out from overcharging when I first got the bike. I was very surprised when it started the bike without being charged. I wouldn't trust it to be reliable.