how often to recharge

stevieb

Esteemed Pedelecer
Apr 5, 2014
292
69
recently fitted a road legal kit from alien cycles to my bike and have been charging it every time i get home even though it still has plenty of charge left.
is this ok to do?
i have only once reached a state of near fully discharged but as advised did not let it fully run out.
is it better to let the battery get near a discharged state occasionally or does it not matter in terms of overall battery life?
thanks
stevie
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,671
the best source of information on Lithium batteries is here:
http://batteryuniversity.com/learn/article/do_and_dont_battery_table
Every time you put the battery on charge, you lose a small amount on your battery capacity but don't let the battery run completely flat before recharging and don't recharge it after only a few miles. Lithium moves between the two electrodes, when it's too flat or too full, one of the two electrode tends to swell and get damaged, it's best to keep the battery between 20% and 80% full in winter if you don't ride much. The best thing you can do for your battery is to ride the bike often.
 

stevieb

Esteemed Pedelecer
Apr 5, 2014
292
69
thanks very much thats exactly the info i am looking for .
i think i will have too charge it less and note down my milage so i don,t get caught out.
i am riding the bike often so thats not going to be a problem .
don,t know if it,s is because i,m new to this and the novelty hasn,t worn off or if it,s the start of an obsession.!
 
D

Deleted member 4366

Guest
It's not a matter of life and death for the battery if you fully charge or discharge it, so nothing to panic about, but do the above where practical and sensible. It'll probably fail for some other reason before it dies from those reasons. The one thing you must not do is run it down to empty and leave it like that.
 
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Aushiker

Pedelecer
I don't know how common these are but EM3V for example has some battery chargers with switches that allow one to set the amount of charge, e.g., to 90%. Seems like a good idea but I don't know how easy it would be to modify an existing charger or even if it is really worth the hassle (as per d8veh comments above).

Andrew
 

stevieb

Esteemed Pedelecer
Apr 5, 2014
292
69
thanks andrew
my charger is not adjustable but i apprieciate the technical info and also confirming the general concensus on the charging issues
 

mike killay

Esteemed Pedelecer
Feb 17, 2011
3,012
1,629
For me, I always recharge because I never know how far I might wish to ride the next time.
If the weather is bad, just round to my daughter's (Half a mile)
Otherwise, could me a few miles or 15, that is the joy of just going out on a bike and following your nose!
 
D

Deleted member 4366

Guest
I don't know how common these are but EM3V for example has some battery chargers with switches that allow one to set the amount of charge, e.g., to 90%. Seems like a good idea but I don't know how easy it would be to modify an existing charger or even if it is really worth the hassle (as per d8veh comments above).

Andrew
You don't have to worry about all that. The battery management system (BMS) already looks after all that. The upper and lower voltages have been set at the correct level to give the best compromise between long battery life and useful battery charger. Why would you want to change it?
 

D C

Esteemed Pedelecer
Apr 25, 2013
1,142
577
How much if any does the ambient temperature affect performance.. I have noticed the first 20% going down a bit faster this winter. But it could be me relying more on it as I get older...
That seems about in line with my experience, very noticeable when close to freezing but back to normal on warmer days.
It's not through getting older for sure.
 

flecc

Member
Oct 25, 2006
53,196
30,602
As with most things dependent on a chemical reaction, the performance of batteries is very temperature dependent, the range of temperatures depending on their chemistry. Our lithium and SLA batteries are at their best at or over 25 degrees C ambient. Below that the performance declines slightly at first but as it gets nearer to freezing point the performance declines very rapidly.
 

flecc

Member
Oct 25, 2006
53,196
30,602
So, let's say ambient temp is around 6 degrees what sort of percentage decline would you expect?
I can't give a figure and to the best of my knowledge no generic scale of temperature reduction in performance and capacity has been published.

I do know that a 6 degrees C the drop is easily recognised, so is likely to be well over 10% and maybe 20% or more to be perceived.

At -20 degrees C most batteries including lithium stop functioning and will deliver no current.