Recharge the battery

[Blimpman]

I'm getting a new ebike with a 48V hub motor and a 10.4Ah, 500W battery. I was wondering how many times can a battery be charged up before it is time for a new one? I expect average charge each time 10% to 80/90%

 

[Sierratim]

I'm getting a new ebike with a 48V hub motor and a 10.4Ah, 500W battery. I was wondering how many times can a battery be charged up before it is time for a new one? I expect average charge each time 10% to 80/90%

How many times can a battery pack be charged? Much depends on the build quality of the battery pack. This includes considerations such as cell quality, BMS (battery management system) sophistication, care used in matching cell internal resistances, assembly techniques, charger sophistication, and more. How the pack is treated after it's put into use also impacts effective life. As you've mentioned limiting charge/discharge levels will impact this, as will storage temps, charge and discharge currents, and level of charge when in storage.
Data from batteryuniversity.com reports up to 3x battery life when charge/discharge is limited to 20-80%. They also report that effective life can be significantly extended with charge currents that are limited to 0.5C and/or discharge currents that are limited to 1C where C(amps) = (battery capacity in WH)/(battery voltage).

With all things considered battery effective life can be highly variable. There are some reference points. For example Specialized offers a 2 year battery warranty assuring the user of a minimum 300 charge cycles with a minimum of 75% of initial battery capacity remaining. Specialized battery packs use quality cells and sophisticated BMS and charger designs. They expect a large percentage of their battery packs to last beyond 300 charge cycles. This can be extended by following the practices discussed above. YRMV.

BTW - I have a Specilaized ebike. At ~35 miles per charge in our hilly town I would need to ride 10,500 miles to get to the 75% capacity Specialized uses as an end of effective life definition. My plan is to buy a new battery as the capacity on the original drops and then use the original as an 'extender' for longer rides. So with my approach the battery never really dies, it just goes into partial retirement.

No definitive answers for your battery I know, but hopefully these are some useful thoughts that you can research further.

 

[Blimpman]

Thank you for the most informative reply!!

 

[theemartymac]

Tims reponse pretty much nails it. And if you plan to ride a lot, and can get a second battery at time of purchase at a discount, that might be a great way to ensure a very long life for both packs. Rotating the batteries between use, and ensuring the battery doesn't have to be fast charged between rides, or charged when particularly cold or hot can also maximize the life. If you just plan to be an occasional casual rider, or if you like to upgrade your stuff every 4 or 5 years at most, it may not be worth the investment, but if you expect to keep the bike to the end of it's useful life or commute primarily on your bike, it's a pretty sound payback.

 

[AHicks]

I'll bet most of us will get 5 years or longer, assuming no serious battery abuse.

Further, a battery sitting unused IS slowly degenerating. For that reason, I would never by an extra battery at the time of sale for use after the original is done. I think we'll be MUCH further ahead going on the battery market when (if) the original poops out. You'll have a fresh battery at that point, it will include any new advances made in battery technology at that point, AND, it's not very likely it's going to cost any more then than it is now due to decreasing prices.

Exception to the extra battery purchase would be if I needed the extra range it would supply, often enough to justify the purchase price.