What’s the BEST way to charge & use an ebike battery for longevity?


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3:31 AM
Jul 17, 2020
Got any ideas? There are some pretty electronically inclined people in this forum, maybe you can share your battery knowledge. I’m guessing one thing would be to store in moderate temps? Do you fully drain, then charge? Half drain? Idk, enlighten me. Thx
Try not to store the battery fully charged for more than a few days. Leave with a full battery and come back on fumes. Repeat as often as necessary. People way overthink this and end up severely restricting their range ability. Batteries are expendable and chances are you will not use one up fully during an average time of ownership anyway. Or a new type will come along to invest in and you can use the old one for shorter rides, it's not like they just dissolve like a tank of gas.

When storing over the course of a long period try to keep at around a 50% state of charge at a temp well above freezing and checking in with the battery once a month or so with a voltage meter and knowing what a full state of charge for your voltage is and how many amps your charger does in an hour.

KISS applies.
OK, I talked to the Specialized and Shimano engineers about this. The advice is... treat it like your iphone. Meaning, no need to take special precaution.

Just charge it fully whenever you want. Unplug when done but no big deal if you leave it on the charger. No need to drain the battery, no need to top it off.

There is NO battery memory, no danger of discharging or overcharging. The big brands have spent an enormous amount of R & D working on their charging technology (and discharging controllers). They do not let the batteries go to zero and they not allow them to overcharge. So, no big deal, just use it.

If you're not going to use your ebike for 6 months or longer, It is advisable to store it around 70% charge. It's the safest storage mode.

If you're using a cheaper (noname) battery and motor, all bets are off. Consult with that manufacturer.

For reference, Charge Cycles is a key attribute of a battery indicating how many times the battery can be fully charged and discharged without losing too much capacity (maintain 80%). Once you exceed that, it will still work, but it well have less run time, just like your iphone. It can be partially discharged and charged of course and those add up to the total. A typical Shimano Steps battery claims 1000 charge cycles. So if you use it to half full each time and fully charge it, then you can do that 2000 times before it loses capacity below spec.
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Shimano e-steps owners manual says you should avoid stopping a charging process before the battery is fully charged. So I will keep on allways charging it to full before disconnecting.
I keep my batteries stored in the bottom of our wine cooler.........55F all the time. LOL
The Bosch battery manual cautions to bring the battery to roughly room temperature before charging.

-Charging – Batteries should be charged in a dry location and at room temperature.
-Storage during winter – Store batteries in a dry location at temperatures between 32° F (0° C) and 68° F (20° C).
-Fully charging or fully discharging results in higher loading of the battery. The ideal charge status for lengthy periods of storage is approx. 30 to 60% or two to three LEDs on the battery indicator.
-Cleaning & care – Cleaning with a direct water jet is impermissible, in particular to protect the electronic components. Before cleaning the eBike, remove the battery. -Occasionally clean and lightly grease the connection port.
-Winter use – During winter use (particularly below 32° F (0° C)) we recommend charging and storing the battery at room temperature be-fore inserting the battery in the eBike immediately before riding it. For longer journeys in the cold, it is advisable to use thermal protective covers.
-Storage – Temperatures below 14° F (-10° C) and above 140° F (60° C) should be avoided.
-Transport – For transport, the battery should always be removed from the eBike and safely trans-ported in your car, for example.
-Inspection – Using a diagnostic unit, the dealer can check the health status of the eBike, especially the battery, and inform you of the number of charging cycle

Here is a link to the Bosch battery manual: https://www.bosch-ebike.com/fileadmi...yGuide_WEB.pdf
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I like to charge at a low amperage if not in a hurry. I can do this as I have a LUNA charger that adjusts from 1-5 amps. You guys with the factory built bikes can't do this i believe. No big deal, just a minor thing, I don't lose any sleep over my batteries as when they are shot, replacements will be even better! As others have said, the one thing I do is NOT fully charge it, and then let it sit for a few days. I have an inverter in my car and often charge while driving to a riding site, and I've gotten to where I can time things just right.

Being a Prius, I can also run the inverter with the car off (not running the engine that is, but actually left ON), with no danger of the accessory battery being discharged) No need for this really, I'm with the "plug it in and don't worry about it crowd", just something I do. Right now I have one 13.5 AH, two 11.5 AH, one 17 AH, and one 6 AH batteries, for three different bikes. All Panasonic or Samsung cells, and each of them amaze me with what they can do.