My ebike battery totally died today. I can't find the model number for the battery as it is not written anywhere.

Here are the pictures:

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  • How do you know it's the battery not the wiring loom or on-switch/control circuitry? Commented Aug 25, 2023 at 15:42

3 Answers 3


That battery case is a common form factor, often called "ebike battery case 03". Based on labels, your battery has 36 V voltage and Li-ion chemistry.

Same case type batteries are still sold in many places online. It doesn't have to be same brand as the same case design is used by many battery pack manufacturers. The voltage should be kept the same, fortunately 36 V is the most common voltage in this case size.

Generally if you keep the same battery chemistry (Li-ion) and do not switch to e.g. LiFePO4, you can use your old charger. But if you are unsure or there is a difference in chemistry, buy a new matching charger for the new battery pack.

  • Currently e.g. BMSBattery sells them.
    – jpa
    Commented Aug 25, 2023 at 11:09

Its a ZAP brand bike, with their custom battery pack. You'll need to buy one of theirs either directly or from a reseller.

Strangely, https://www.zapebikes.com/products.html does not list replacement batteries as something you can order.

With some technical know-how it may be possible to replace the cells inside the battery, but that's more of a question for for electronics.SE

  • Oh that's sad then, will it work if I buy something like the following: aliexpress.com/w/… Commented Aug 25, 2023 at 3:42
  • 1
    In case of doubt, contacting the manufacturer is always an option. Might be that they don't regularly sell replacements direct to consumer but only through wholesale and can lead you to a shop or come up with another satisfactory solution. If they are straight unsympathetic of your request, bring their "sustainability" claims into play. ;-)
    – DoNuT
    Commented Aug 25, 2023 at 6:34
  • @DoNuT yep - if its dead/dead then repacking can be a good way to rejuvenate the whole pack, though cheaper than a whole replacement its generally still 2/3 the cost to repack vs all-new. Though also a repack will give you newer cells than a potentially-old-stock item, and possibly even higher capacity than when new.
    – Criggie
    Commented Aug 25, 2023 at 11:14
  • 1
    @Criggie Just based on the fact that there is some nice and competent support out there that tries to handle things in favour of their customer. There must be a plan for (reasonably) old bikes, or they have something in stock, steal it from a demo bikes... Even Garmin sends you discount codes via support if you bemoan that their wristband strap replacements are pretty expensive^^
    – DoNuT
    Commented Aug 25, 2023 at 11:30
  • 1
    Repair questions are not on topic for electrical engineering.SE. They usually end up as a can of worms, the best ones actually help multiple persons, the good ones help one person, and most of them help no one really.
    – Arsenal
    Commented Aug 25, 2023 at 13:43

If you can't get a new battery, you might be able to get a company to rebuild that battery pack with new cells. I've had good luck with these people:


They were very responsive and were willing to put in a specific charging port for me. I've also heard batteriesplus will do similar things.

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