Getting the best from a lithium polymer battery

[Steve989]

Hi everyone!

I've just bought a new Sparta electric bike with a lithium polymer battery. The dealer said I should run the battery from full charge to more or less flat two or three times in the initial stages of ownership. He said this would improve the battery's range.

However the bike's manual doesn't mention this - it just says the battery should be fully charged before first use and that it doesn't have to be flat before re-charging. And I've read elsewhere that modern batteries don't need to be "primed" in this way. But surely the dealer would know, so I'm confused.... Can anyone help?

Also, the manual says that to look after the battery I need to recharge it after every use. So if I took the bike to work I'd have to detach the battery and charge it, even though I have enough range to get there and back home without a recharge. This is a big disappointment as it adds to the amount of "faff" associated with the pedelec. Can anyone tell me how important it is to recharge after every use?

Many thanks
Steve

 

[flecc]

Running it flat initially applies to some batteries which have sophisticated integral meters showing their content. This sets the meter zero point for meter accuracy, hence the dealer advice. I don't know if your Sparta has such a battery, but it won't do any harm to run it very low once initially.

You don't need to charge every single use, just charging once a day in your circumstance is fine. Charging itself creates battery stresses so charging too often can also shorten life. It sounds like the Sparta is ideal for your purpose in the way you want to use it.
.

 

[Nealh]

Your battery is a Li-po rather then Li-on so is made up of soft flat pouch cells rather then solid cylindrical common type ones, so the chemistry is a little different. It will still be protected by a BMS so discharge and charging will be controlled, however these cells degrade if left for any long spell at full charge over the long term so as with RC Li-po pouch cells if you plan on not using the bike for any length of time keep the battery in storage mode of at about 37.5 - 38.5 volts.
In general these batteries are better charged just before use.
If not in use for a few days or longer leave at storage charge.

 

[Steve989]

Running it flat initially applies to some batteries which have sophisticated integral meters showing their content. This sets the meter zero point for meter accuracy, hence the dealer advice. I don't know if your Sparta has such a battery, but it won't do any harm to run it very low once initially.

You don't need to charge every single use, just charging once a day in your circumstance is fine. Charging itself creates battery stresses so charging too often can also shorten life. It sounds like the Sparta is ideal for your purpose in the way you want to use it.
.

thanks - the dealer seemed to think running it low would extend the range but as far as I can see that only applies to older types of battery. Am glad I don't have to charge after every use.... have spent a lot of money on this bike so want to get it right!

 

[Steve989]

Your battery is a Li-po rather then Li-on so is made up of soft flat pouch cells rather then solid cylindrical common type ones, so the chemistry is a little different. It will still be protected by a BMS so discharge and charging will be controlled, however these cells degrade if left for any long spell at full charge over the long term so as with RC Li-po pouch cells if you plan on not using the bike for any length of time keep the battery in storage mode of at about 37.5 - 38.5 volts.
In general these batteries are better charged just before use.
If not in use for a few days or longer leave at storage charge.

thanks....what's a BMS?

 

[flecc]

thanks....what's a BMS?

Battery Management System. Our lithium batteries have an internal circuit that monitors the individual cells and controls their charging to ensure no damage, and also balances them evenly in the late stage of a charge.
.

 

[Steve989]

Battery Management System. Our lithium batteries have an internal circuit that monitors the individual cells and controls their charging to ensure no damage, and also balances them evenly in the late stage of a charge.
.

Ah ok thanks - hopefully that means the technology is pretty robust even if conditions not perfect

 

[Deleted member 4366]

Don't do it. It'll do more harm than good. The advice to cycle your battery is just misinformation propagated from the early ebike batteries that were completely different.

 

[Steve989]

Don't do it. It'll do more harm than good. The advice to cycle your battery is just misinformation propagated from the early ebike batteries that were completely different.

Thanks - that's what I was beginning to think but there's lots of contradictory views out there. When I Googled it, this was the advice from http://electricbikeshoponline.com/service/proper-battery-care:

DO I NEED TO “BREAK IN” MY BATTERIES?
A: Yes, it is recommended that you perform a “break-in” cycle consisting of three discharge/charge cycles to
allow your batteries to reach optimum performance. This involves three complete discharges and three complete
recharges. After this initial “break-in” cycle the batteries will have maximum possible performance and less line
voltage fluctuations under load.

 

[flecc]

Thanks - that's what I was beginning to think but there's lots of contradictory views out there. When I Googled it, this was the advice from http://electricbikeshoponline.com/service/proper-battery-care:

DO I NEED TO “BREAK IN” MY BATTERIES?
A: Yes, it is recommended that you perform a “break-in” cycle consisting of three discharge/charge cycles to
allow your batteries to reach optimum performance. This involves three complete discharges and three complete
recharges. After this initial “break-in” cycle the batteries will have maximum possible performance and less line
voltage fluctuations under load.

That's completely wrong for lithium batteries as d8veh has said, it belongs to types with older chemistries.

The only exception is the one I mentioned previously, doing it once initially to set the zero point for meters on some specific batteries, or at much later occasions when and if the meter setting drifts out.

The only ones I know of that applies to are:

Panasonic batteries specifically made for their second series crank units.

Kalkhoff-BMZ batteries made for the above Panasonic units and their own Impulse and Ergo units.

These battery meters are integral to the battery casing and have two separate functions, measuring the charge content or measuring the capacity. For best accuracy both rely on the zero point corresponding to the battery being empty of content usable on the e-bike.
.