Charging pattern

[Tomtomato]

Hi,

I have a bike with a lithium ion battery.

I am only using it once a week, and usually far from emptying the battery, so I am not sure about the best charging pattern to extend (or preserve) the battery life.

Should I recharge the battery after each use?

Should I recharge the battery before each use?

Should I only recharge the battery once its almost flat (after several weeks)?

I think the manufacturer recommendation is to have the battery 40% charged for long term storage, and occasionally discharging completely the battery (to recalibrate the capacity "gauge").

Not sure however what's best for short term storage (i.e. a week).

Thanks,
T.

 

[Gubbins]

I just keep topping mine up usually from about half full and 3 years on it still performs well.

Sent from my SM-G920F using Tapatalk

 

[flecc]

The 40% charge for storage only has value if storage is at very low temperature, close to zero degrees C. At room temperatures it makes little if any difference.

If you've discharged around a quarter or more of the capacity, it's worth topping up the charge. The bike will always be ready to perform at its best then.
.

 

[Wander]

I think the manufacturer recommendation is to have the battery 40% charged for long term storage, and occasionally discharging completely the battery (to recalibrate the capacity "gauge").

From Bosch:-

No memory effect
The PowerPack with lithium-ion cells can be briefly charged at any time regardless of its charging state. Interruptions of the charging process do not harm the battery. Complete discharge is not required.

No self-discharge
Even after prolonged storage, such as during the winter, it is possible to use the rechargeable battery without recharging it. This means PowerPacks do not need to be recharged after a long break in use. For extended storage, a charge of approx. 60 % is recommended.

Storage during winter
Store the batteries dry and at room temperature. Between 15 °C and 20 °C is optimal. Being completely charged or completely discharged is hard on the battery. The ideal state of charge for extended periods of storage is about 50 to 60 %, or three diodes lit up on the battery indicator.

 

[paul20v]

I charge mine everytime i finish riding no matter if it was a 10mile ride or 60mile ride
As above li ion batterys have no memory issues but they should always be kept fully charged when in regular use

 

[Tomtomato]

they should always be kept fully charged when in regular use

Not sure that's correct.

From what I have read elsewhere, it's apparently best to keep the battery charged between 40% and 80%. More or less is not good for the battery life.

Therefore, keeping the battery fully charged or topping up all the time could be actually damaging.

 

[Tomtomato]

According to this page: http://lifehacker.com/5875162/how-often-should-i-charge-my-gadgets-battery-to-prolong-its-lifespan

1) Best to perform shallow discharges (as opposed to emptying the battery each time)

2) Best to do small charges

3) Best to keep the battery between 40% and 80% charged, as opposed to fully charged

 

[paul20v]

Not sure that's correct.

From what I have read elsewhere, it's apparently best to keep the battery charged between 40% and 80%. More or less is not good for the battery life.

Therefore, keeping the battery fully charged or topping up all the time could be actually damaging.

Ive read all this too ,
But you have too remember that the battery management circuits are looking after the battery better than me or you ever will ,
Unprotected cells thats a different thing all together thou
One thing i do know is im not sitting in my garage waiting for the battery to get too 80% then switching it off ive got better things todo
Seriously thou isnt this another thing battery managment circuits sort out by only allowing the batteries to be charged too 4.2v when the batteries unprotected can be charged too higher voltages ,
So i also question what voltage do these battery experts say fully charged is ? Is it the 4.2v or is it for example slightly more this meaning that the 4.2v battery managment cut off is actually only 80% of what the battery can realistically be charged to even thou higher voltages will shorten the cell life

Another thing ive read as well is you should do a full discharge every 30 or so charges because of digital memory loss then they say lithiun ion batteries dont have memory issues , this isnt really explained in full that ive found so far , either they have memory or they dont
Have you found anything on your reading explaining this contradiction ?

 

[anotherkiwi]

My Li-ion I ride, I charge, if it is open road riding. Around town use I ride for several days or until it gets below 37.5 V.

My Lipo I treat the way the people over at ES told me to...

 

[Geebee]

Charge after every use, my Tonaro battery is 2011 and as good an new as far as I can tell, Hobby King battery similar age and still as new.
I not changing the way I treat them in view of the above.

 

[Tomtomato]

Another thing ive read as well is you should do a full discharge every 30 or so charges because of digital memory loss then they say lithiun ion batteries dont have memory issues , this isnt really explained in full that ive found so far , either they have memory or they dont
Have you found anything on your reading explaining this contradiction ?

Yes, there is no memory effect indeed for a Lithium Ion battery. However, apparently, the battery management system can slowly misread the capacity/become miscalibrated, and therefore the advice is to fully discharge the battery every 30 cycles or so, to recalibrate (so that capacity can be reported properly/accurately again by the bike computer).

 

[Tomtomato]

I not changing the way I treat them in view of the above.

I have a large capacity battery (17Ah), so I will probably from now on try to keep the battery between 40 and 80% charged. It's much easier to do on a large capacity battery.

This means not recharging before or after each small trip (e.g 30 miles), or doing only a shallow recharge/not recharging fully (unless I am expecting to do next a very long trip).

This could mean the battery lasting twice or three times as many charging cycles.

 

[flecc]

This could mean the battery lasting twice or three times as many charging cycles.

I very much doubt that. We have many members who always charge to full and get as much as 5 full years of daily use out of their batteries, far better than the average.

The key things are the quality of the battery and its specification relative to the current draw, and the management system. Our interventions usually make little if any difference.

Of course if you can keep between 40 and 80% of charge it will help, but the difference it makes to battery life will be small, not remotely like the two or three times you mention.
.

 

[Tomtomato]

I guess if their daily commute is only using 10/20% of their battery capacity, and they only recharge by the same amount, then it could be fine.

However, if they almost empty their battery each day, then it should damage the battery quickly.

I guess my conclusion is that people should aim to buy higher capacity batteries than their actual needs, if they want the battery to last longer, in term of charging cycles.

I wish also that manufacturers would have a battery saving mode (i.e. button/switch), whereby the battery would only report 40-50% of its true capacity, and the charger would stop at 80%.

I used to have a Lenovo laptop that had a battery protection mode, charging only the battery to 80% its capacity, so I guess it does make a difference.

 

[paul20v]

Charge after every use, my Tonaro battery is 2011 and as good an new as far as I can tell, Hobby King battery similar age and still as new.
I not changing the way I treat them in view of the above.

Im with you there
Messing about for maybe a little bit more life is not for me
I want to ride the bike not stare at it wondering if i should switch it off before its fully charged because it may or may not be better

 

[paul20v]

Yes, there is no memory effect indeed for a Lithium Ion battery. However, apparently, the battery management system can slowly misread the capacity/become miscalibrated, and therefore the advice is to fully discharge the battery every 30 cycles or so, to recalibrate (so that capacity can be reported properly/accurately again by the bike computer).

Another contridication by the so called experts thou
They say dont totally discharge your batteries , then say totally discharge them every 30 cycles or so which might calibrate the electronics but will also upset the cells
I guess no matter what you do somethings going to be unhappy
Im going too keep doing what i do arses too the so called experts

 

[Tomtomato]

Yes, it's indeed a contradiction: they advise not to discharge the battery fully, but also to discharge the battery fully once in a while. However, that's to recalibrate the battery capacity reading, and not required for the battery itself.

If you don't mind for the capacity gauge on the bike to be inaccurate, then you don't need to fully discharge.

Yes, no need to listen to some experts advice (with all their science and experiments), best to listen to people on forums who, based on statistical evidences of 3 other posters, advise to recharge the battery fully each time...

 

[EddiePJ]

Life's too short and I'd sooner charge the battery back up after each ride, rather than have to cut my ride short because I didn't charge it back up. I'm with Paul20v.




.

 

[paul20v]

Life's too short and I'd sooner charge the battery back up after each ride, rather than have to cut my ride short because I didn't charge it back up. I'm with Paul20v.




.

And on that note im off for a ride with my fully charged battery

 

[flecc]

Yes, no need to listen to some experts advice (with all their science and experiments).

Your mistake is in overvaluing that advice. All their science and experiment are based on the testing of cells, not systems. Our e-bikes use complete systems which are often designed as an integrated whole and adequately protect the batteries from charge extremes damage.

The greatest damage to batteries in almost all of our systems is not from overcharging or over discharging, simply because they are protected against these happening.

No, the greatest damage is from very high rate discharging under load, something that only a few of the very best systems protect against, Panasonic notably the best in this respect with their complete systems.

You are however on the right lines in using the largest battery possible since that slightly reduces the damage from high discharge rates, though by not nearly enough to prevent it. Only a good system can help with that.

To illustrate what I'm speaking of, look at what geo-stationary satellites have. Their batteries have to last at least ten years and over 3600 charges, something we could only dream of. It's done by overspecifying the battery capacity to around seven times what is needed. During every 24 hour cycle they use about a seventh of the capacity during the dark phase and then recharge to full during the much longer sunlit phase. Clearly charging to full isn't harming them since it's done over 3600 times, the only thing they suffer is the inevitable loss of capacity over time since the chemistry can't endure indefinitely.

Of course this illustrates the fundamental problem on e-bikes, for size and weight reasons batteries cannot be greatly overspecified. Our systems alleviate that by strong control over charge extremes, but only rarely control the discharge rates sufficiently.

We can add some extra help by adding more limitation to charge extremes, though that makes very little difference, but it's often difficult to avoid very high discharge rates with our limited battery sizes.
.