Added a new battery monitor...(Aili)
Battery Monitor == Fun! Plus: How to avoid a common mistake regarding AH total I have a couple 2015 Thor Majestic 28a RVs. I added a 2nd 12v battery to the coach (they only came with one). My ba...
Forum Discussion
https://www.walmart.com/ip/EverStart-Lead-Acid-Marine-RV-Deep-Cycle-Battery-Group-Size-29DC-12V-845-MCA/20531543
The photos show an 860 and an 830 MCA for that "845" Anyway, one photo of the top of the 830 says in a red patch, "115AH at the 20hr rate"
So your 845 MCA ought to have the same red patch with maybe "122AH at the 20hr rate" in it?
Beats me how that 845MCA at 58.7 lbs can be 122AH when the 59.7lb Interstate one is 98AH.
When you get your monitor going, you can get the battery down to 50% as seen on your hydrometer, about 1.200, and by resting voltage around 12.1-12.2, and then charge it up and see how many AH it will take to be full (as seen on the hydrometer at 1.280 ish) and double those AH.
Trouble with that is heat loss on the recharge, if the monitor has the right allowance for that. Better to have it full and then discharge it over a 10 hr period at its 20 hr rate--use 5 amps for assumed 100AH-- then when at 1.200 SG, stop and wait for an hour, check voltage is about 12.1-12.2 and then double those AH. No heat loss on dischargeto skew the results, but it takes ten hours.
The photos show an 860 and an 830 MCA for that "845" Anyway, one photo of the top of the 830 says in a red patch, "115AH at the 20hr rate"
So your 845 MCA ought to have the same red patch with maybe "122AH at the 20hr rate" in it?
Beats me how that 845MCA at 58.7 lbs can be 122AH when the 59.7lb Interstate one is 98AH.
When you get your monitor going, you can get the battery down to 50% as seen on your hydrometer, about 1.200, and by resting voltage around 12.1-12.2, and then charge it up and see how many AH it will take to be full (as seen on the hydrometer at 1.280 ish) and double those AH.
Trouble with that is heat loss on the recharge, if the monitor has the right allowance for that. Better to have it full and then discharge it over a 10 hr period at its 20 hr rate--use 5 amps for assumed 100AH-- then when at 1.200 SG, stop and wait for an hour, check voltage is about 12.1-12.2 and then double those AH. No heat loss on dischargeto skew the results, but it takes ten hours.
