Yeah, way simple. I’m glad I didn’t blow myself up. Ha.
Feel free to make public, if I can do it anyone can.
3.47 is a good charge voltage . mine currently shuts off a little lower then that . i did pull a cell out of the bank after charging and charged it manually to 3.65v and it took about 4% more , so not much . And at the 3.45 they should last longer . I use the 24s bluetooth balancer and love it . Running 26 ncells so 2 aren’t hooked up . easy to check just 2 . The balancer will make your pack very tight on soc and makes it easy to monitor . Nice install.
This may be nearest the elusive drop in pack yet.
My 20s have taken 27ah and are 15mv delta.
Pick it up again in the morning.
Mike, thanks for the feedback. Curious if you notice much of a difference with that other cell hooked up? I’m guessing 25s is gonna be plenty for me but not opposed to improving on it if it’s worth it.
You will need to change the charger if you add another.
25s is the sweet spot for stock voltage.
46ah into 20s and 26mv delta-v
Looking good for not needing bms on these.
didn’t notice much of a difference . i drive mine like a porsche so i’m hard on the pack . The extra cell increased voltage and reduced amperage draw some . But it is a harder install . You will have to have your charger reprogrammed .
64ah and quite a voltage spread at the top.
My point is that it doesn’t matter. I may pull this one down a little, but if all the cells have 64ah in them, I’m good to go.
Agree?
my guess would be in a couple of cycles # 19 is going to go high on you . I would pull it down and give yourself a buffer.
I just went out and looked. All cells are 66 or 67ah.
#19 is 62ah. Exactly the result I would expect.
This is a test pack for a local 48v golf cart. I won’t need #19.
Might be a good test for the balancer. To see how long it takes. On the other hand, there is a good chance of messing up the balance of the rest.
P is the batch number.
Strange indeed.
Balancer was never turned on.
Great news! Took the cart out on the maiden voyage with the new batteries. I took it down just until there was one green bar left on my battery gauge (not sure how accurate it is so I didn’t want to push it). I got 19 miles range out of the batteries and could have easily gotten 20+ if I pushed it a little. With my old batteries I never got better than 16 miles range. Plus, it was only 47 degrees here; I’m assuming the batteries will do a little better when it’s warmer.
Not only did I notice better range but the acceleration was much better. I also could maintain full speed while going uphill; the previous batteries wouldn’t allow me to do that.
I periodically checked the voltage and none of the series got below 3.22. When I pulled it into the garage I checked all of them and they all fell between 3.22 and 3.25. Pretty good I’d say.
I don’t know why anyone wouldn’t put these in their GEMs! Thanks for all the help and direction!
Remind me.
Number of cells?
Bms/monitor?
25s. I previously had gel batteries, just swapped these out and didn’t change anything on the charger. No BMS or balancer. Really was a ‘plug n play’.
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That is great results . If you had 3.22v remaining you had more miles left . But good not to run them all the way down on a regular basis . 4 of us took my cart on a 21 mile trip this week , 35+ mph . Battery pack still had more in it . Keep them tightly balanced and they will treat you right . These green cells work very well . What was your final charge voltage per cell ?
While charging they got up to 3.45. But once the charging finished they were all 3.35 or 3.36. They seem to stay balanced very well so far.
On a side note…how much work does it take to get my GEM going 35?
tell us about your gem . year , model ,Tire size . Motor