Need Help Picking Battery Bank

Dave Angelini

lkruper wrote: »

Is a fire more likely when a charger is trying to compensate with a probe that is not measuring the temperature properly than a charger that does not have a probe at all?

A fire is extremely unlikely to begin with. In answer to your question if you have the rare event of thermal runaway/or?, either case you listed could be bad. It would depend also if the bad sensor was measuring hi or low. They usually fail open. If you are there during generator use or EQ, you really should not have more than a healthy concern with any kind of battery. If you are clueless you probably should not be using batteries.Please do not take that wrong, it just needs to be said once in awhile.

lkruper

Dave Angelini wrote: »

A fire is extremely unlikely to begin with. In answer to your question if you have the rare event of thermal runaway/or?, either case you listed could be bad. It would depend also if the bad sensor was measuring hi or low. They usually fail open. If you are there during generator use or EQ, you really should not have more than a healthy concern with any kind of battery. If you are clueless you probably should not be using batteries.Please do not take that wrong, it just needs to be said once in awhile.

Thanks, I am more concerned with something happening when I am not there. I can visualize that if a charger is programmed to increase charge at a lower temperature with the use of a probe that if the probe failed it could over-charge, over-heat the battery.... and that this is something that cannot happen if the charger does not think it knows what the battery temperature is. If that is true, then there needs to be a risk/benefit analysis of using the probe.... the battery lasts 10% longer with temperature correction but there is an X% chance of failure which could also take out the battery, or in a very small percentage of the time cause a fire.

Do I have this right?

Dave Angelini

Unless you have a ridiculously small battery bank and alot of solar, normal charge set-points from solar are not going to cause a fire because of a temperature sensor issue during bulk and absorption.The temp sensor has a small range that it can move! Direct experience with XW and Outback gear.

You could have a defective charge controller that would not stop increasing voltage!

I had a customer in Baja who could not get home for three days because the roads were washed out from a hurricane. The lightning fried his charge controller and each day the unloaded battery went to 70 +V on a 48 volt bank. He added water and was fine. An AGM might not like that and ?