Battery Charging

[SDharlie]

Quick question

If my battery is at:

50% and I charge it to 80%

90% and I charge it to 100%

80% and I charge it to 100%

10% and I charge it to 90%

are all these considered ONE cycle in the life of the battery ?

[OptimusPrime]

I see where you are going with that question but the fact is that the charge cycle estimate for a particular battery is just that, an estimate. None of the examples you gave are a full charge cycle except perhaps the last one. A charge cycle is defined as fully charged to fully discharged to full again. Anything less is a partial charge and doesn't have the same impact on the life of the battery. For example, if you charge your battery up to 80% from let's say 20% you can expect to double the rated life of your battery. So if it was rated at 500 cycles, you just increased it to 1000! Also, if you have the battery sitting at 80% as in your example and then charge it to 100% right before a ride that is good too. These batteries don't like to sit around at 100% so if you need a full tank, a good plan is to do that final topping up right before you ride.

[Lance Tesla]

That is my battery management procedure: store at low charge/80% and charge to 100% then ride within 1 hour. Usually I get on the bike within 10 min of reaching a full charge, leave my driveway and climb a steep street for about a 1/4 mile to get to the trail. My batteries will be obsolete before they wear out.

[SDharlie]

I see where you are going with that question but the fact is that the charge cycle estimate for a particular battery is just that, an estimate. None of the examples you gave are a full charge cycle except perhaps the last one. A charge cycle is defined as fully charged to fully discharged to full again. Anything less is a partial charge and doesn't have the same impact on the life of the battery. For example, if you charge your battery up to 80% from let's say 20% you can expect to double the rated life of your battery. So if it was rated at 500 cycles, you just increased it to 1000! Also, if you have the battery sitting at 80% as in your example and then charge it to 100% right before a ride that is good too. These batteries don't like to sit around at 100% so if you need a full tank, a good plan is to do that final topping up right before you ride.

Thanks for that. Previously I was under the impression that any charge at all was considered a cycle. The way you have explained - "A charge cycle is defined as fully charged to fully discharged to full again" makes sense. So basically if I charge to 100% and go for a quick ride and it goes down to 95% and I wish to top it off again by putting the 5% back in, that is not bad right?

[JPLabs]

It's not as bad as a full cycle, no. But it's not as good as cycling from, say, 60-65% for that same energy use. As noted above, they don't like to be kept full all the time. If you do a lot of short rides, it would be better to do several rides on one charge, taking the battery down to half full or so, then recharge to 80% and repeat. Pack spends less time sitting around as full, that way. Charge fully once in a while, though, so it can balance the pack.