Looking after a new Lithium ion battery - help please

[wightrider]

Now I have my lovely new battery pack installed I am now wondering how best to keep it at it's optimum. I read a lot about storing the battery at 80% charge but how is this realistically attained. The best way I could think of was fully discharging it in normal use then calculating how long you need to keep your charger on so that it can be switched off when 80% is reached. This does of course assume a linear charging curve and I don't know if my charger does that.
What do you guys do to keep your Lion battery tip top?

 

[flecc]

I just fully charge each time and recharge whenever I've used more than a quarter of the content. Our bike's systems prevent overcharge and cut off long before the battery is empty so do a pretty good job of protection. Only charging to 80% is beneficial, but not to any great degree, the battery quality is far more important than how we care for them. In any case, since the charge and battery system doesn't allow a charge to reach maximum, we have no way of knowing what 80% is.

Assuming the system stops 10% short of peak charge, we'd only need to stop 10% short to achieve the 80% figure.

So I just prefer to use to the full and enjoy, not worrying too much about the nth degrees.
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[Deleted member 4366]

It probably doesn't make any difference what you do with the battery. Most of the advice that you get is out of date. the manufacturer installed a battery management system (BMS) in the battery that looks after the maximum and minimum voltage for charging and normal use. Avoid extremes of temperature. Don't leave it in a hot shed in the summer or anywhere that freezes in the winter.

Many battery cell makers now put ingredient X in their cells that avoids all the problems from the past.

If you want to be really pedantic, don't store your battery fully charged for months at a time. You don't have to store it at 80%. The level doesn't matter. A ride around the block will be enough to drain it away from maximum.

I always store my batteries fully charged. They seem to last pretty well, but I can't say that they would have lasted longer if I had done something else.

Never store your battery fully discharged.

 

[wightrider]

Thanks for the replies guys. Useful to know.

 

[anotherkiwi]

Another way to look at it is take the price of the battery and divide by 3 then by 52 and you will have a weekly cost for the battery. Mine is 2.37€ which comes to about 0.02€ a km. My new Lipo battery is 0.03€ a km but calculated over one years use!

I am not losing any sleep about battery cost.

The best way of looking after a battery is to use it often!

 

[Lister]

I have two Samsung 48 volt 12 ah batteries for my bike.
I keep both fully charged,but do not use the bike much in the winter.
Both batteries came with their individual chargers, which look identical and have co-axial plugs.
Question one.
The spare battery lives indoors
The bike lives in the garage which is not heated am I better taking the battery off the bike and bringing it indoors?
Q2.
Are there any meters which can tell the charge state of the batteries?
.

 

[flecc]

Question one.
The spare battery lives indoors
The bike lives in the garage which is not heated am I better taking the battery off the bike and bringing it indoors?
Q2.
.

Cold is better for minimal capacity loss in storage, but that's only measurable in long term storage at near zero degrees C. At normal ambient temperatures indoors or outdoors in the UK, it makes little difference.

This chart from the battery university site shows you how little the difference is at most temperatures.
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[Lister]

Thank you Flecc,the link was denied,so will go direct.

 

[anotherkiwi]

Are there any meters which can tell the charge state of the batteries?
.

The meter on your bike should give you voltage. In an ideal world storage voltage is 3.85 V per cell or 46.2 V in the case of a 12S 48 V battery.

 

[Lister]

The meter on your bike should give you voltage. In an ideal world storage voltage is 3.85 V per cell or 46.2 V in the case of a 12S 48 V battery.

Thank you, battery two which I thought was fully charged lasted but a few minutes a couple of days ago. This battery is my spare.
I need to check both batteries on the bike, despite the cold weather.

Cold did not bother me over half a century ago.

 

[Ian Thompson]

I'm getting very strange battey usage lately. Today It was zero degrees the bike was outside for a few hours, went back and 50% of charge was gone.

What sort of milage are others getting in the cold. I have a 36v and 8.8amp.

again how do i best check the stae of the battery?

 

[Kinninvie]

I'm getting very strange battey usage lately. Today It was zero degrees the bike was outside for a few hours, went back and 50% of charge was gone.

What sort of milage are others getting in the cold. I have a 36v and 8.8amp.

again how do i best check the stae of the battery?

You are always going to get less out of your battery when the temperature is near freezing.
My batteries gave about 3/4 of their usual mileage yesterday because it was so cold.
I use a multimeter to check voltage levels accurately,I have lots of wattmeters and difital gauges but none are really accurate.

 

[Deleted member 4366]

I'm getting very strange battey usage lately. Today It was zero degrees the bike was outside for a few hours, went back and 50% of charge was gone.

What sort of milage are others getting in the cold. I have a 36v and 8.8amp.

again how do i best check the stae of the battery?

We need a bit more info. When did you charge the battery? How far had you gone before you parked it outside? What makes you think that there was 50% charge gone? What was the charge state before you parked it?