Interesting discovery while topping off water in house batteries

[Rich W.]

Well two 12’s in parallel for the chassis, or three groups of two 6s in series for house, they’re still both 12v battery banks of LA batteries and it would seem the same bulk, absorb, and float voltages would apply, with amperage determining how long it takes to charge each bank. How that magic happens to me is a bit of a mystery beyond my assumption that it’s all regulated by various electronic adjuncts - BIM, BIRD, relays, ….etc. Right? I guess I should be more up to speed on this but as long as its all working, I have other things to concentrate on.

 

[Kevin D Pem]

Well two 12’s in parallel for the chassis, or three groups of two 6s in series for house, they’re still both 12v battery banks of LA batteries and it would seem the same bulk, absorb, and float voltages would apply, with amperage determining how long it takes to charge each bank. How that magic happens to me is a bit of a mystery beyond my assumption that it’s all regulated by various electronic adjuncts - BIM, BIRD, relays, ….etc. Right? I guess I should be more up to speed on this but as long as its all working, I have other things to concentrate on.

So your saying that ahr is programmed for the two banks separately?

 

[Kevin D Pem]

So your saying that ahr is programmed for the two banks separately?

Or are you saying it is a time thing and capacity is not an issue?

 

[Rich W.]

Or are you saying it is a time thing and capacity is not an issue?

not sure I understand the question(s), but I am surmising that the chassis batteries hit their eq charge of 15.5 first (rather quickly actually) because there are just two of them and they are fairly new - less than a year old. At that point I shut them off (started worrying about them), and let the house bank “equalize”. That took several more hours. Once everything was at rest both sets showed 100%, so life is good.

so….charging/equalizing is/was a time thing, and capacity is good (100%) so not an issue? I’m a little slow sometimes, so if I still don’t get it, just let me know.

 

[Joe Dutchstar]

Here is some useful data on Equalizing. (as I quietly mumble thank god for LiFePo)

RV Tech Library - Equalizing Batteries

www.rvtechlibrary.com

BU-404: What is Equalizing Charge?

BU meta description needed...

batteryuniversity.com

 

[Rich W.]

Here is some useful data on Equalizing. (as I quietly mumble thank god for LiFePo)

RV Tech Library - Equalizing Batteries

www.rvtechlibrary.com

BU-404: What is Equalizing Charge?

BU meta description needed...

batteryuniversity.com

Right - the first one is in my library; I’ll add the second. Thanks!

 

[Kevin D Pem]

not sure I understand the question(s), but I am surmising that the chassis batteries hit their eq charge of 15.5 first (rather quickly actually) because there are just two of them and they are fairly new - less than a year old. At that point I shut them off (started worrying about them), and let the house bank “equalize”. That took several more hours. Once everything was at rest both sets showed 100%, so life is good.

so….charging/equalizing is/was a time thing, and capacity is good (100%) so not an issue? I’m a little slow sometimes, so if I still don’t get it, just let me know.

So neal brought up dissimilar batteries! The batteries are dissimilar in size. But if a time is set rather than voltage, then the thought would be boil time, not state of charge so to speak. If there is a question it would be do you know if it's time or amp hours that determines equalize settings.

 

[Rich W.]

So neal brought up dissimilar batteries! The batteries are dissimilar in size. But if a time is set rather than voltage, then the thought would be boil time, not state of charge so to speak. If there is a question it would be do you know if it's time or amp hours that determines equalize settings.

I guess I’d have to break down and read the manual to find that out and then determine how it was set up by the factory or previous owner. But the fact that my two-battery chassis bank got there a whole lot faster than my six-battery house bank is somewhat telling.

This discussion has also led me to surmise that a build-up of sulfate gunk on the plates may well have been responsible for the initial discovery that I posted at the beginning of this thread since I had never equalized in three years of use.