We have three 12V wet cell small car batteries for powering GPS base and external radio, and robotic total stations. When not in use they are left on CTEK smart chargers. The charging station is in the office, which is under aircon about 12 hours each day. I??d been away recently for a few weeks so nobody was checking the chargers and when I got back, all the chargers were showing fault light. One battery had over 12V on it, one was about 11.5V and the other was 4V.
The one that was 4V looked like it had no fluid in it, and the 11.5V was not much better, the 12V one looked ok. I can only presume that the aircon has had its tentacles down the vent holes and evaporated the water, unless some pilgrim stole the juice while I was away. I've just refilled them with ??battery water? (not the acid juice), and within an hour the 4V (not connected to a charger) has crept up to 7V and I??ve put the other two on charge to see if they'll charge up and wont get to the fault light.
Also, the positive terminal on one has corroded right through and collected this gunk. This has happened before. The terminals are home made using those light gauge hobby electrical lugs that you can solder things on to.
?ÿ
One other related concern is that I have a 2005 BMW X5 that has the battery (I??m fairly sure it is wet cell and not AGM) in the rear of the car, inside the cabin, so it is ??touched? by the aircon, and therefore if this aircon-evap-your-battery-water phenomenon is true, the same thing could be happening there.
Keep an eye on that charger.?ÿ My guess is it failed and overcharged the batteries and boiled the water and acid out.?ÿ That would explain the mess and corrosion.?ÿ A smart charger workimg right wouldn't do that.?ÿ
I don't think a little air flow would have had that much effect.
Buildup around a?ÿ battery terminal can indicate leakage. I have fixed batteries with a two in one epoxy mix and spread thickly around the area where terminal fits into the battery case. It will also seal a hole in a battery.
Distilled water is best for refilling batteries. The minerals in regular tap water will cause the electrodes to decay faster.
Being constantly connected to a charger will cause it to heat up and that will cause gaseous pressure and the liquid or gas from the chemical reaction inside the battery will find a way out. You can smell the gas from battery acid.
If the battery is too hot to the touch, it needs to be taken off charger.
Cold weather will drain a battery.
A battery stored on a concrete floor will fail quicker.
I am probably replacing a battery in one or more electronic gadget every week.
Sometimes smart chargers catch a case of the stupids.?ÿ I've had similar chargers that were supposed to charge then switch to maintain/trickle charge forget to switch and nearly burn my house down while charging a couple of 9ah AGM's.?ÿ The batteries and chargers were both only a few weeks old and the first time I let them run more than overnight they kept charging at the higher charge rate until the batteries overheated and swelled so bad the cases started leaking.?ÿ Wet batteries will just boil dry in an overcharge situation and the acid vapor will corrode everything in close proximity.?ÿ
A battery stored on a concrete floor will fail quicker.
That was true many decades ago when the cases were made of other materials.?ÿ Enough acid soaked through the case and reacted with the concrete so that?ÿ a slight conduction drained the charge.?ÿ Plastic cases fixed that.?ÿ
The myth persists because leaving a battery anywhere in a poor state of charge for a long time also kills it.
