Welcome Paul,Hi All,
My first post here. I just bought a converted GEO with 10 AGM batteries.
These were great batteries in their day, but are becoming tired (C&D Technologies UPS12-475FR) I am getting 5 miles or so out of them (easy) 25 to 45mph ... during this cold weather (35-44degrees) and thats all we really need for our runs to the store. So I hope to get a few more months use out of them.
I have done a refresh charge on them (as per the manufacturer) of 2.4v per cell. And maybe that helped but not by much.
My thought is to add 2 fresh batteries to help out...here's how, and let me know if this is a really bad Idea.
My controller is a Kelly 144 volt (KDH14500B)
My Charger is a Quick Charge set to 120V system.
I have 10 12v batteries currently
My DC-DC is a 128V-12 Sevon
I thought I could add 1 or 2 more batteries in the series, but leave the Charger connected on only the 10 existing batteries, thus maintaining the existing pack. Then Charge the new battery(s) with a separate charger.
Thus the only time the old and new would be in the "series" is during actual driving. They would be charged separately.
Q? Would they need to be (more) separated during charging? (there is a big disconnect which is off when car is not used)
Q? Could I connect the DC to DC to wires tapping only 128V (orignial 10 batteries) would I be better off removing DC converter and using a separate battery for 12V (short drives anyway)
Q? is there any reason to hook new batteries in parallel to (one or two ) of the original batteries (just during driving) instead of series
Q? would adding 2 batteries in the series help with reserve power, thus drain the current batteries less during our 5 mile drive.
Q? Any other thoughts on getting more time out of these batteries before they are recycled? (and I find a great deal on new ones)
If you added two batteries to the series and charged them how you described it would work IF the chargers are isolated.
Adding cells in series will decrease the current required for your normal driving and will increase your range. Normally adding new cells to old cells would be bad if you were going to charge them together, however if you charge them seperatially then you should be fine. Also running the dc/dc converter off part of the pack would be bad if you weren't charging seperatially.
It's not the ideal solution, but it would get you a little life and extra range out of the pack.