Author Topic: 48v 40ah lifepo4 battery  (Read 3992 times)

Offline Phelix

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48v 40ah lifepo4 battery
« on: August 23, 2015, 07:14:16 AM »
Has anyone used a 48v 40ah lifepo4 battery with a goldenmotor magicpie before? If so how fast does it go and how many miles does it get? I currently have a 48v 15ah battery and it seems that its starting to go kind of bad. I am not getting nearly as much distance out of it or nearly as quick as speed as I used to get. I am thinking of maybe getting a more powerful battery.

Offline Lollandster

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Re: 48v 40ah lifepo4 battery
« Reply #1 on: August 24, 2015, 09:10:07 AM »
If the battery you have now is lithium it might just be out of balance. If it is a Golden Motor battery I'm sure someone here can tel you how to balance it.
I had a 18650 type battery that became unbalanced during the winter. I got less than 10km on a charge (36v10ah) and leaving it on the charger for days didn't help. The BMS was not up to the task. I ended up opening the battery and balancing it manualy with a lipo charger. Now it is like new again.
Disclaimer: I know nothing.
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Offline AdamB

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Re: 48v 40ah lifepo4 battery
« Reply #2 on: September 18, 2015, 03:55:17 PM »
+1

I have to agree with the above poster! In my experience, the #1 reason that people say their batteries are dead is due to the cells being out of balance (also potentially dangerous). That's followed closely by a single cell giving up the ghost!

Tear that pack open (unless under warranty, then just use the warranty) & put a multimeter to each cell! Then individually balance/charge/discharge & repeat a bunch of times... That usually does the trick!

Alternatively, if you don't want the old battery anymore & don't want to play with it, give it to me! ;) I'm in desperate need of any lithium type batteries/cells I can get my fingers on. I am really poor & only have +200lb  SLAs that's weight is killing me... I'll figure out what's going on with the pack, reuse anything possible & ensure the rest is properly & ethically recycled!

As for the range potential of a 48v 40A pack, the best way to figure that out is to multiply whatever your range is for the old pack when new by 4. As an estimate (multiply volts by amps & divide sum by watts used & then multiple 2nd sum by speed), so...

48vx 40A= 1,920Ah/350w=5.48571420hrx 44km/h= 241.371429km estimates range...

BTW- I made a couple rough estimates but if you plug your actual numbers into the above calculation, you'll get a more accurate range estimate! If math is not your strength, use the address bar & it'll do the actual calculations for you! I do so when I'm being lazy... I hope this is helpful...

Adam