Where to measure battery temperature

[zboss]

I was completing my first attempt at battery equalization last weekend and I understood that I should monitor battery temperature to make sure they did not overheat.

I was wondering WHAT I should be monitoring... should I monitor on the outside case side, the top, or the acid temp itself? I was using an IR thermometer and not depending on my Mastervolt sensor. Unfortunately, I only had time to equalize for 3 hours and the batteries never got above 99F.

Unfortunately, and I am hoping someone can clarify my understanding, because it is my understanding is that its the temperature that equalizes the batteries by melting the sulfites back into solution. Is this true or just part of the equation?

[colemj]

No, it is not temperature that resolvates the sulfates. The warning to monitor temperature is more of a safety recommendation because you are applying a higher voltage that could dump a lot of current if something went wrong. You can simply feel the top of the negative terminals to make sure they are not getting hot. Or use your IR thermometer if you want to be more precise. They will get warm, but if they are hot, you should disconnect the charging. I would consider "hot" as anything above 110*F.

Mark

[leftbrainstuff]

Sulfates aren't melted they diffuse from a solid compound back into the electrolyte through electron transfer during the charging process.

The rate of reaction varies with temperature. Monitoring temp during equalisation is for protection of the battery itself from physical damage.

Monitor the posts is the most practical.

Sent from my GT-I9300 using Cruisers Sailing Forum mobile app

[cheoah]

Originally Posted by colemj

No, it is not temperature that resolvates the sulfates. The warning to monitor temperature is more of a safety recommendation because you are applying a higher voltage that could dump a lot of current if something went wrong. You can simply feel the top of the negative terminals to make sure they are not getting hot. Or use your IR thermometer if you want to be more precise. They will get warm, but if they are hot, you should disconnect the charging. I would consider "hot" as anything above 110*F.

Mark

Our word for the day: resolvates

Emphasis on re or solv?

Ya zboss, shoot the terminals with your IR. It is good enough for a battery monitor temp sending unit.

[HappyMdRSailor]

I always search for the warmest location.... Not the same on all setups from boat to boat to be sure... One boat it's the neg post input... Another it's a middle series batt case...

(cheoah gotta a new av, we got some of them round things in MS too...)

[colemj]

Originally Posted by cheoah

Our word for the day: resolvates

Emphasis on re or solv?

Ya zboss, shoot the terminals with your IR. It is good enough for a battery monitor temp sending unit.

Sorry. Should be "solvates" - no "re" needed.

Mark