12v batteries reading 14.18v

They have been an awesome pair of batteries!

I hope I haven't shortened their life too much by this recent incident. But so far, every time I think they are on their way out it turns out my problem is something different. They are cold, or the charger is going or something.

I cannot tell you how many chargers I have gone through with this one set of batteries. They drop like flies, but the batteries keep going.

Are these really 12 year old batteries? And they are still doing the job for you, in a commercial application? (I'm assuming the shave ice is not just for you alone!)

If the answer to both of those questions is yes, congratulations and keep doing what you are doing!!

One more thought -- you mentioned the ammeter -- using the ammeter when the device is running is (I think??) the only way to get an accurate reading of the current draw.

Never heard of anyone adding water to "gel cells"
I have read of people doing it to AGM cells
With AGM it has to be done a little at at a time ,usually with a syringe, as the water has to percolate down thru into the glass mat
Aka be absorbed into the glass mat holding the electrolyte

I have an ammeter, but trying to use it when the machine is under load would be pretty darn difficult.

I've had this particular pair of gel batteries for a dozen years or so, and I got them used. I've never seen a resting voltage above about 13.10 before.

They were 12.77 volts this morning, so I charged them gingerly for about half an hour, then used it a little bit, and charged again for about 10 minutes. Will see what the voltage is in the morning.

landyacht, do you think I should try to add water to these batteries?

One of the pair tends to have some electrolyte leaking around one of the terminals. It's done that for the whole 12 years I've had it. I clean it off once in a while. The other one does not normally do that, but it does have a tiny bit of leakage now since the giant overcharge.

I think you said you have to drill a hole to add water? I'm pretty hesitant to mess with them.

Any solar?

A 12v battery reading 14.18v open circuit, rested, 18 hours removed from the charging source @ 50 degrees F, is not right.

I've no experience with Gel batteries but I expect I would have read something about their incredible surface charge retention, if it is actually true, in the 2 decades I've been reading about lead acid batteries and experimenting and collecting data on their performance.

What one mostly reads on gel batteries is their incredible cycle life when charged properly, and their premature death when not charged within their well published parameters.

Don't praise your charger yet, see how the batteries perform the next time.

As I said every time I noticed well above normal surface charge retention with my flooded battery, some of the cell's plates were exposed, and once refilled properly That voltage retention ability was erased along with some portion of the battery capacity, never to return. I imagine voids in gelled electrolyte could do something similar as low electrolyte levels on a flooded marine battery.

Get a clamp on ammeter. Guessing sucks and actual numbers/data rule.

Thanks, time2roll, I didn't realize that! Although I'm talking here about the voltage on the battery posts 18 hours after charging. But I'm glad to know that my charger is not as **** as I thought.

I call normal on this one. I see charging specs at 14.4 to 14.6 for MK Gel.

Thank you, folks.

They are gel batteries, not AGM. They are reading at 14.18 volts each. I didn't realize a charger could overcharge them that badly :(.

They performed well yesterday in a long run, thank goodness. I will see what their voltage is this morning, after the overnight rest. I did not charge them today after use.

I don't think I can get an amp reading off the motor when it is overheating. I don't want to put it in that state again if I can help it. I can tell you my 100-amp breaker did not trip.

You need less "run time" for the charger. 14.18 VDC is fine for charging, but high for float level. Yes, it will overcharge the batteries.

Set the timer to run it fewer hours a day.

And, as said, check the voltage a couple of hours after turning off the charger and hopefully not running a load. That will give you an indication of how much charging needs to be done.

The other VERY GOOD way to tell if more/less charging is needed is to measure AMPS that the charger is sending to the batteries. If below 5-8 amps, you don't need to keep charging.