Giant Energy Pak Charging Options?

gtd2000

Finding my (electric) wheels
Oct 29, 2019
21
1
I was dropping off a trailer load at the local recycling centre last week and a woman was about to toss an Energy Pak Battery (Giant) into one of the containers.
I said I could possibly repurpose the battery and I'd take it if she didn't mind.
Was thinking of using it on my old school lead acid powered bike.
She explained that it wouldn't charge but I thought that the worst case scenario would be harvesting any usable cells in the pack.
After a cursory look at the Energy Pak it looks like a few of the connections were somewhat furred up with corrosion, presumably from being stored in damp conditions or water ingress.
Is there any cheap and cheerful way to attempt charging this battery without the official unit? One of my pals thought the BMS might be in the charger, rather than the battery pack?
Any ideas?
 

vfr400

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Jun 12, 2011
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I was dropping off a trailer load at the local recycling centre last week and a woman was about to toss an Energy Pak Battery (Giant) into one of the containers.
I said I could possibly repurpose the battery and I'd take it if she didn't mind.
Was thinking of using it on my old school lead acid powered bike.
She explained that it wouldn't charge but I thought that the worst case scenario would be harvesting any usable cells in the pack.
After a cursory look at the Energy Pak it looks like a few of the connections were somewhat furred up with corrosion, presumably from being stored in damp conditions or water ingress.
Is there any cheap and cheerful way to attempt charging this battery without the official unit? One of my pals thought the BMS might be in the charger, rather than the battery pack?
Any ideas?
The BMS will be inside the case. To use it for another bike, you'll need to replace the BMS with a Chinese one, which isn't too dificult. If you open the case, you can charge it with any charger of the correct voltage (normally 42.0v) by connecting it directly to the cell pack as long as you check the individual cell voltages from time to time, especially when getting near full. No single cell must be allowed to go over 4.2v.
 
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Nealh

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Aug 7, 2014
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For charging if you change the BMS for a generic one, try and replace the charge port or drill out and add a new panel mount charge port to the case to suit your own charger. DC5.5mm x 2.1mm are quite common type and all mine use that or a 5.5 x 2.5, handily one can get a 5.5 x 2.5 - 2.1 jack converter.
 
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gtd2000

Finding my (electric) wheels
Oct 29, 2019
21
1
Thank you both for the replies.

It sounds like I'll need to do a bit of research but looking on eBay etc., it appears that the Giant chargers are around £120+...!!!!

I'll have a look at my existing charger for the 36v lead acid battery pack and see what kind of voltage that outputs.
 

Nealh

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SLA chargers no good for lithium cells as they don't charge to 42v.
 
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Nealh

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Aug 7, 2014
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It will work if the charge connection is the correct fitting.
 
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