Charge to 80% or 100% ?

[egroover]

Hello all

Bit of background..My daily commute on my Crossfire-e uses approximately 40% of the battery.

I have a timer plug that can run the charger for 2, 4, 8 hrs etc and then turns off the charger.

I re-charge to 100% after using the bike ( I recharge it from 60% to 100% every day), so have been setting the timer to 4 hrs, which is more than enough to fully charge the battery.

I recently read some stuff that suggest to get the longest life (as in number of years of use) from the battery, it's best to charge to 80 or 90% only. I can achieve this if I put the timer plug on 2 hours every day

Be grateful of any thoughts or advice

Cheers
Paul

 

[D8ve]

Charge to 100% the last hour or so is used for balancing. No balancing and the battery will lose power and could go puff.
The magic smoke is nice but without it the battery is dead.

 

[JuicyBike]

It's best to avoid keeping the battery at 100% charge, so charge as late as possible, just before you ride.

The balancing stage is important but has to come at the end of the charge, obviously.

To increase longevity massively a charger designed to charge to only 90%, including a final balance stage would be a big improvement.
But manufacturers focus on range quotes and so squeeze everything they can from a battery. A pity, especially considering the environmental impact of early disposal.
I wouldn't angst too much though. You're using your battery regularly. We generally find that batteries that are used often last the longest.

 

[Gringo]

It's true that useing any lithium cells between 20 & 80 % will improve there life but it's not always possible or practical.
If you know it's not going to be used for a long spell don't leave it fully charged.
Saying that, in the real world over several years I don't think you'll notice the difference, especially if say in four or five years you batter is only holding 80% charge,that's still two days riding.
Sure if your already on the batterys limit on day one then any loss will leave you shot of your destination, that's when you have to just get fitter and pedal harder
I run lipos in my RC's, once a month I take 4 full charged lipos to a meeting, use 2 and have 2 backups, the next month I'll use the backups (still fully charged) & the last used ones will be topped up as my backups for that meeting. So I've always got some fully charged lipos sitting around for months at a time.
I've been cycling these same 4 lipos for about 5 years with no noticeable loss of capacity

 

[awol]

I run lipos in my RC's, once a month I take 4 full charged lipos to a meeting, use 2 and have 2 backups, the next month I'll use the backups (still fully charged) & the last used ones will be topped up as my backups for that meeting. So I've always got some fully charged lipos sitting around for months at a time.
I've been cycling these same 4 lipos for about 5 years with no noticeable loss of capacity

Wow 5 years use is really good although I'd read these rc-lipo batteries were supposed to be left at storage charge for anything longer than 48hrs and only charged when needed?

 

[Gringo]

Wow 5 years use is really good although I'd read these rc-lipo batteries were supposed to be left at storage charge for anything longer than 48hrs and only charged when needed?

True lipos can and are used hard and fast, certainly pushed to there limits they have quite a short life but I run 1/10th scale trials trucks, slow and précis driving with high wind, low power motors.
Buggy racing was a battery killer, 100% down to 10% in 8 minuets, the motors would be to hot to touch and only the best batterys would last 30-40 cycles.

 

[anotherkiwi]

You have confirmed my suspicions. Using LiPo on a bike drawing 15 Amps will be similar to your low drain usage. If you are hotrodding and generally drawing high Amps they won't last as long.

In any case I ride, recharge to storage voltage when I get home and top up to 4.15 V per cell the morning before riding again. During breakfast and preparing to go out. This week I couldn't use much of the charge because of an incident and in the 6 days since voltage has dropped by 0.02 V. Some of that is me plugging the Wattmeter in every day to check that all is well.

 

[egroover]

Thanks all, really appreciate your comments
Looks like the general concensus is to fully charge back up to 100% every time, so it's good to get that advice. I wasn't aware of the battery balancing process, so that's interesting that it happens at the end of the charge cycle, so it makes sense to carry on as I was with the full charge.
Here's to many years of battery life ! (until the next gen of half the size and double the power batteries - hopefully !!)

Cheers

 

[anotherkiwi]

The problem is that people think of the battery as they think of a petrol tank in a car. It isn't just the tank it is also part of the petrol so you are going to use it up with each charge and each km you ride.

My bottle battery is fading after 18 months and about 4000 km. The hills have done a lot of damage because I am demanding a lot of Amps on each ride out of town. I expect the total cost of the battery to be somewhere between 0.04 and 0.05 € per kilometer, add to that less than a euro cent of electricity per kilometre.

Compare that to the cost per km of running any other motorised means of transport or a bus ticket for example - once you have that perspective you stop worrying about your battery getting used up.