36V Silerfish battery (Ancheer) only charging to 37.5V

[Tsmith]

I just bought the City Cruise for my daugher at college. The battery dies after just 4 miles or so. I bought it from a guy selling it for his wife. She thought it was too big for her. They bought it in 2/2022 so suspect the battery sat uncharged for a while. It is the silverfish style battery back that sits behind the seat tube 36V 12.5ah bottom discharge. I can only get it to show one of the two green bars on the indicator light on the battery and when i check the output voltage of the battery with my voltmeter I get 37.5 Volts. I've tried a couple of things I read on reviving a battery mistreated in this way. I have left in on the charger for 36hours, I've run it down on the bike until i cuts out multiple times then charged. I can still only get it to charge to 37.5V. It won't charge to the 42V full charge. Any ideas on how to resurrect this battery. The bike and battery where only used for about 2 miles previously.

 

[Tsmith]

If you feel this thing battery is shot where is the best place to get a replacement? I've seen them on ebay and also that i can get them rebuilt Hi-C. Anybody have experience with some buying a replacement battery?

 

[UtahPete]

Does the bike run the way it's supposed to? I don't get why you're concerned.

 

[Tsmith]

Does the bike run the way it's supposed to? I don't get why you're concerned.

No it dies very quickly. Lasts maybe 5 miles. A 36V ebike battery should charge to 42V when fully charged. I'm only getting what amounts to a 50%ish charge.

 

[E-HP]

No it dies very quickly. Lasts maybe 5 miles. A 36V ebike battery should charge to 42V when fully charged. I'm only getting what amounts to a 50%ish charge.

Trying to figure out which bike you have to take a look at specs online. Is it this one, or something else? (a pic of the bike and battery label may be helpful).

https://www.amazon.com/Electric-Bicycle-Upgraded-Commuter-Removable/dp/B096ZPT192?th=1

Normally when buying a used ebike, you should assign $0 to the value of the battery pack, so hopefully you got a deal. On buying a new pack, a simple rule would be to buy one that has the cell brand/type listed in the description (e.g. LG, Samsung, Sony, Panasonic, etc.). It's a big selling factor, so frequently it will appear right in the listing title. It will also show up in the price, but with ebike batteries, you may not always get what you pay for, but you definitely won't get what you don't pay for (if it's cheap, it's junk), so don't get fooled by some super deal and end up with a dorm room fire. You can get a decent pack made of generic Chinese cells, or a hunk of junk, so be careful going that route. You could also post the link to ones you are considering so folks can dissect the listing.

EDIT: or maybe this one? very little info on their webpage.

ANCHEER Electric Bicycle, 26” Electric City Bike, Low Frame Electric Bike with 36V/12.5 Ah Lithium Battery and 350W Powerful Motor, Step Through Commuter Ebike with Basket for Woman Man，Free Lock Available-AN5928

ancheer

ancheer.shop

 

[Tsmith]

Yes, it's the second one. Thanks for your reply. I paid $325. So even with a new battery I won't be to bad off.

 

[docw009]

Your battery is unbalanced and really cannot be fixed. It's called a Silverfish battery. When looking at a replacement, make sure the new one has the bottom connectors arranged with the same polarity. There is no standard for it. You can rewire the bike or the battery to reverse them if needed, but better to get it right.

I bought my replacement silverfish from UPP battery. Something like this one with generic cells. They sell a higher quality one with brand name cells.

 

[E-HP]

I bought my replacement silverfish from UPP battery. Something like this one with generic cells. They sell a higher quality one with brand name cells.

That LG pack looks like the way to go. Double the capacity of the stock pack

 

[Tsmith]

Thanks for the replies. I appreciate it. It's her bike at college so was trying not to spend too much money. I ended up buying a battery from eBay for 250. I'll probably regret it but at least I'm only into this bike 600 bucks when it gets stolen.