Electric Bike Battery Repair & Repacking

I never bought a production ebike never seen one I want to own. So you do repairs yourself to large lithium packs, huh? Build your own BMS? What ebike(s) do you own and ride?
 
... I have a Trek Pure, 2 KHS Smoothies, 1 scratch built from bare frame, A KHS step through, 1 Kick scooter, and a rear DD Bikes Direct fat bike. There's a WATTWAGON fatbike sitting in a shipping crate waiting for me to do a review.
That's a lot of bikes for one butt. Must cut into a guy's riding time.
 
Thank you for this helpful post! I was looking for a source to rebuild the batteries for my 5 year-old Ego Flash. I reached out to three ebike battery builders you've mentioned in this and prior posts. Hi-C out of Colorado and Rechargeable Power Energy of Las Vegas, NV were the vendors who were able to rebuild my specific batteries. I went with Hi-C because Patrick knew exactly what bike my batteries were from just by the pic I sent him. He was also more detailed in explaining Hi-C's rebuilding process AND his price was more reasonable. I have since received the rebuilt batteries and they are a 100% improvement over the original batteries. They are better than new! I just wanted to post about my positive experience and complete satisfaction with Hi-C and appreciate the great info you continue to share on EBR forums. Gracias!
 
"Most replacement packs are priced $500 to $900 but their repair service costs around $300."

Insofar as this is true and the service is good, this seems pretty ideal. I wonder what tooling is required - seems like something that should be available in every major city.
 
Would make a nice small business for some technical geeks depending on location.
 
I think that I destroyed my RadRunner Plus battery by touching the charging port with a key, which produced a spark. Now the battery is not charging. Is there anything that I can do to save it? Thanks for any help.
 
cost of repair with two way shipping will often be more expensive than buying a decent new battery, if we’re lucky there might be an internal fuse. Keying a charge port is sadly not uncommon.
 
I've removed the 5 amp fuse and am going to replace that before giving up on it. It works again.
 
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I've also thought about rebuilding battery packs, but the clear trend these days is that in the future you won't be able to.

Numerous apartment fires in NYC have prompted the city council to recently ban anything not UL certified, and also I think the re-use and re-building of batteries. There are excellent cells (LG, Panasonic, Sony) and then there are the cells from China that are often of poor quality and prone to failure. And when a lithium pack fails it makes an enormous fire that can't be extinguished. Hence the ban, which I think will spread to the entire country. And certainly rental agreements for apartments will insist on no lithium batteries inside without the UL label. Plus, presumably a sealed container preventing any internal repairs or replacements.
 
Can I test a battery to determine if it's losing it's life,we have four 36 volt batteries [long story]but would like to know if they are needing repair.Buy the way Hi-C repaired one and I would not hesitate to use them again,
I want to have them ready for spring.
 
You can test current capability by loading battery with a resistor and checking the voltage at the same time. I use a 10 amp resistor pack, 5 ohms 600 watt for a 48 v battery. It should support 10 amps for AH rating divided by 10 hours. Should be above minimum voltage at that time. Start at full charge. Do these tests outside on concrete or dirt. Wear safety glasses. Don't touch a burning battery or a hot resistor. I mount my ceramic wirewound resistors above the support surface to keep differential cooling from shattering the case. A fan can help de-stress resistors operated near power limit. Be aware the metal case and TO-220 resistors stocked now at distributors require an aluminum heat sink to achieve the watt rating. Much cheaper are wirewound ceramic core resistors sold mostly at electronic surplus houses. Those will stand rated watts as is where is.
If you want to detect internal high resistance, build a 25 amp resistor pack if your controller goes that high. For a 48 v battery say a 2 ohm 1400 watt resistor pack. If voltage drops more than 20% with that load you have a problem. Don't run the full time.
 
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To measure capacity, you can buy a wattmeter, around $10-16 depending where you buy them,. Put on connectors that match your charger. Then when your battery is flat, recharge it and see how many AH or WH it took,

WATTER.jpg
The wattmeter can also be put between the battery and ebike controller, if you put in connectors. Then you can see how much WH/AH was used on a ride. However, they lose all the readings if you run the battery flat so you can't measure full discharge unless you use a second battery to power the meter.
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In theory, the recharge is 5-10% higher than discharge, I still find it useful to measure a ride, if I don't run down the battery, They record peak amps for example and minimum voltage, which is good info on what your bikes uses, and voltage sag on a battery,

There's other ways to test discharge. I bought an Atorch load tester which allows one to choose the current and how low to run the battery. It's limited to 160 watts, so a 48V battery can't be discharged higher than 3 amps, Thesea are aboyt $40 from China and 2x higher on amazon. The glowing disk is a cooling fab, festooned with LED's. This is more accurate than the above, but the tool is pretty fragile.
Atroch.jpg
 
To measure capacity, you can buy a wattmeter, around $10-16 depending where you buy them,. Put on connectors that match your charger. Then when your battery is flat, recharge it and see how many AH or WH it took,

View attachment 166602
The wattmeter can also be put between the battery and ebike controller, if you put in connectors. Then you can see how much WH/AH was used on a ride. However, they lose all the readings if you run the battery flat so you can't measure full discharge unless you use a second battery to power the meter.
.
In theory, the recharge is 5-10% higher than discharge, I still find it useful to measure a ride, if I don't run down the battery, They record peak amps for example and minimum voltage, which is good info on what your bikes uses, and voltage sag on a battery,

There's other ways to test discharge. I bought an Atorch load tester which allows one to choose the current and how low to run the battery. It's limited to 160 watts, so a 48V battery can't be discharged higher than 3 amps, Thesea are aboyt $40 from China and 2x higher on amazon. The glowing disk is a cooling fab, festooned with LED's. This is more accurate than the above, but the tool is pretty fragile.
View attachment 166603
Thanks for the very good info, however way over my knowledge of testing, batteries are two years old and we ride a lot in spring through summer and fall. I have noticed quite a difference when I pull the cart with the puppy .
 
Another way to test them is to ride the same route til they go flat and note the mileage between the different packs.

If your Hi-C guy is local. ask him for a testing quote.
 
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