Battery Temperature

[scarlet]

I've been having electrical issues on my boat that I've been trying to rectify. A couple of weeks ago I had a battery over charge issue and i one if my batteries swelled and smoked. When I checked the temperature, it was over 180 degrees. I am waiting to see if I can figure out where my issue lies before I replace the batteries.

In the meantime, I've stopped running the charger all the time and have instead only turned the charger on for an hour or so several times a day to keep the batteries charged.I check the battery temperatures while i they are charging so they don't over heat, but I'm not sure how high is too high? Most of my bank hovers around 80-90 degrees when charging, but I have 2 that quickly climb to over 100 with in an hour and a half of charging and I get scared and turn the charger off.

Can anyone tell me the acceptable surface temperature range for an AGM battery?

I have 5 12v/170 AH victron Super Cycle batteries....

[DefinitelyMe]

Is this degrees Fahrenheit or Celsius? Hopefully the former!

I don't know what the 'official' numbers are. All I can tell you is that our Lifeline AGMs are never more than a couple of degrees (Celsius) above ambient. They don't get warm to the touch at all.

Why not give the manufacturer a call / email?

It sounds like you have a big issue. My guess would be something like a shorted cell in one or more of the batteries. That would cause what you describe.

[scarlet]

Yes.... Fahrenheit....

[tkeithlu]

I'm going to be very surprised if those overheating batteries do not have shorts. All that heat has to be coming from somewhere. As a first step, I suggest that you isolate each battery and run a simple load test on them. Dollars to doughnuts one or more is simply bad.

Here's the cheap way:
https://www.harborfreight.com/100a-6...ter-61747.html

and here's one level up:
https://www.amazon.com/TT-TOPDON-AB1...=thedrive09-20

[GordMay]

Your batteries are too hot at 180°F.

For all types of lead acid batteries, you should avoid charging, if the temperature raises above 40 to 49 degrees Celsius, or 104 to 120 degrees Fahrenheit.


According to Trojan:
[1] “As a rule of thumb, for every 10°C increase in temperature, the reaction rate doubles. Thus, a month of operation at 35°C (95°F) is equivalent in battery life to two months at 25°C (77°F) . Heat is an enemy of all lead acid batteries, FLA, AGM and gel alike, and even small increases in temperature will have a major influence on battery life.”
[2] “In hot ambient operating temperatures, cells temperatures exceeding 43ºC (110ºF) should be avoided. A battery on charge will experience approximately a 10ºC rise in cell temperature in an ambient range of 35ºC (95ºF). Charging should be more closely monitored in temperatures >95ºF. Charging currents should be reduced or charging should be stopped until the battery is allowed to cool if 43ºC (110ºF) is exceed as very serious damage can occur at temperatures of 52ºC (125ºF).”

1 ➥ https://www.trojanbattery.com/pdf/AG...tLineSheet.pdf

2 ➥ Operating Temperature Ranges : Technical Support

[Jammer]

When one battery out of several is overheating, it is typically the result of an internal short. They are usually caused by manufacturing defects or insufficient electrolyte.


On FLAs, the definitive way to diagnose a shorted cell is to disconnect the battery and apply a reasonably heavy load (say, C/2 or so). Electrolyte in the shorted cell, if one is present, will boil.

[scarlet]

Originally Posted by GordMay

Your batteries are too hot at 180°F.

For all types of lead acid batteries, you should avoid charging, if the temperature raises above 40 to 49 degrees Celsius, or 104 to 120 degrees Fahrenheit.


According to Trojan:
[1] “As a rule of thumb, for every 10°C increase in temperature, the reaction rate doubles. Thus, a month of operation at 35°C (95°F) is equivalent in battery life to two months at 25°C (77°F) . Heat is an enemy of all lead acid batteries, FLA, AGM and gel alike, and even small increases in temperature will have a major influence on battery life.”
[2] “In hot ambient operating temperatures, cells temperatures exceeding 43ºC (110ºF) should be avoided. A battery on charge will experience approximately a 10ºC rise in cell temperature in an ambient range of 35ºC (95ºF). Charging should be more closely monitored in temperatures >95ºF. Charging currents should be reduced or charging should be stopped until the battery is allowed to cool if 43ºC (110ºF) is exceed as very serious damage can occur at temperatures of 52ºC (125ºF).”

1 ➥ https://www.trojanbattery.com/pdf/AG...tLineSheet.pdf

2 ➥ Operating Temperature Ranges : Technical Support

This is exactly what I was looking for. I have 2 batteries that exceed that range whilst charging.... So I will get them replaced as soon as possible....

[sailorboy1]

Originally Posted by scarlet

This is exactly what I was looking for. I have 2 batteries that exceed that range whilst charging.... So I will get them replaced as soon as possible....

If my batteries even seemed “hot” i would replace them. 180 is waaaay past ‘seems” hot.

[smac999]

Get those batteries out right now and stop using them and charging them. They can explode.

Likely one is shorted internally.

[SalingSue]

Battery is toast
Hopefully it’s a west marine or something and you can return it

Sounds like your charger is junk, had great luck with this one for a AC to DC
Works on AGM, lithium, it’s Bluetooth and even has a power supply mode



https://www.victronenergy.com/chargers/blue-smart-ip67-charger-waterproof

[Cheechako]

I have had at least 2 batteries over the years that developed an internal short. It's not that unusual even though not old batteries. They would draw the bank down after charging. They would be much warmer than the other batteries after charging, and can be ID'd that way.

[donradcliffe]

Measure the voltage across the battery terminals when the charger is on. If it's more than 14 5 volts, the charger is the problem. If it's not, isolate each battery in the bank, and check the voltage across the terminals. If they all are about the same, wait an hour and retry. The batteries with shorted cells will have a voltage near 2 volts lower than the rest, another should be the batteries that were hot. You can hook the rest of the bank back together and use it until you replace the bad batteries.