How to properly break in a new electric bike battery and extend its life

Court

Administrator
Staff member
Hi guys, I've been talking to lots of different shops and manufacturers about this and it sounds like the best way to break in a Lithium battery for ebikes is to discharge it to ~50% the first few times (don't discharge all the way but also make sure you discharge it at least 40-50%).

In the past I've heard some people say it's good to discharge all the way but more and more people have been telling me this can be hard on the chemistry. After the first few times hitting 50% then you can start charging it after every single ride (even shorter ones). I was also told that once the battery is charged you can unplug it from the charger (and unplug the charger as well to reduce phantom draw) so this will keep the battery from slowly leaking out. If you just unplugged the charger from the wall, the battery might trickle out into the charger so again, completely unplugging it is best.

This is just what I've heard but I'd consider the people I've been working with to be knowledgeable. If you have anything to share here to help people break in and maintain their batteries to get the best range and lifespan please chime in!
 

James

Well-Known Member
I've heard the same. Jamie from Swissborn told me that once my battery was charged to unplug it from the charger because of that phantom draw you talk about above. Kinda weird but I've been doing it for months and have had 0 problems... must be true!
 

Court

Administrator
Staff member
Cool, thanks for the supporting information. To clarify, phantom power draw happens when you leave anything plugged into the wall (wasting electricity) and battery drain happens when you leave an electronic device connected to the charger but not plugged in... juice sort of trickles backwards into the charger :)
 

Paul E.

Active Member
I've been wondering for a while how this all relates to the battery life specified in charge cycles: if e.g. the quoted life is 500 cycles, does it matter whether you charge from 95% to full, from 50% to 75% or from 50% to full? If you plug in and unplug the charger 500 times in one day, is the battery then dead? :) Any ideas?
 

Ravi Kempaiah

Well-Known Member
I've been wondering for a while how this all relates to the battery life specified in charge cycles: if e.g. the quoted life is 500 cycles, does it matter whether you charge from 95% to full, from 50% to 75% or from 50% to full? If you plug in and unplug the charger 500 times in one day, is the battery then dead? :) Any ideas?

First of all, the lifespan of the battery greatly depends on the quality of the cells and the discharge cycles depend on the rate/quantum of discharge.
Re: your question of 100% discharge vs 20% discharge, they are very different.

The reason why Prius/Tesla can guarantee 8 year life span or 100,000 miles is that the BMS restricts the flow/discharge to partial cycles only and thereby extending the life. By maintaining battery operation in that sweet-spot zone, you get lot more cycles.

Batteries.JPG


Source: Battery University

The take away is if you want to go 20 miles one-way commute, you could use 6Ah battery and drain it fully and recharge at work but the life span of the battery will be ~500 cycles.

One could get a larger battery like 15Ah and use only 30% of the charge for 20 miles one-way commute, recharge at work and get ~1000+ cycles.
 
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Paul E.

Active Member
Thanks, good info. Makes me think that seeing the life span simply measured in cycles might mislead many to think that the fewer times you charge the battery, the longer it lasts, when just about the opposite is true.
 

Ravi Kempaiah

Well-Known Member
Thanks, good info. Makes me think that seeing the life span simply measured in cycles might mislead many to think that the fewer times you charge the battery, the longer it lasts, when just about the opposite is true.

That is true. Many ebike dealers are awfully misinformed about many technical things. You can see such information on brochures as well.
 

opimax

Well-Known Member
The logic of this makes even more sense because the cost of a 6amp battery is usually more than 1/3 do an 18 amp so if you saved money initially by buying the small battery you pay more in the long run.

I do have a question about the BMS though. When my Stromer says 10% left does that number really mean 10% of the battery or what the engineers designed and equate to a safer number on a battery say 25% of a non BMS battery?

Mark
 

JoePah

Well-Known Member
Well the current thinking is that you do not want to fully charge your batteries or fully discharge your batteries... Cellman, a Chinese manufacturer of quality batteries, offers chargers that do just that, allowing charging to 90 or 95%. He claims to have better service life.. you can read his reasons here.

Having charged my A2B batteries over 800 cycles over 4.5 years I can tell you that fully discharging your batteries every time cuts into the long term capacity. OTOH I got to take my bike everywhere so I'm not sure letting battery life dictate my enjoyment is a good idea either. I used to pedal the bike waiting for a voltage return so I could squeeze another mile out of it.. They specifically told me NOT to do that.. screw it..lol

Basically I lost 10% capacity every year on average.. The truth is the batteries were fine for 2 years, then really started degrading.. After 800 cycle on my LiMn batteries ranges was down to a lousy 55%.

So with today's pedelec bikes you can get 30 miles per charge, and you can accurately read your battery state of charge.. Not letting the battery discharge lower than 15% doesn't seem like too much of a penalty to enjoyment.

If I were buying a new bike today I would buy the absolute largest battery offered.. After that use the bike as you please, but try to charge it drains below the lower voltage cutoff point. And if the battery range becomes unacceptable go buy another one.. they're 500 or whatever.
 

JoePah

Well-Known Member
The logic of this makes even more sense because the cost of a 6amp battery is usually more than 1/3 do an 18 amp so if you saved money initially by buying the small battery you pay more in the long run.

I do have a question about the BMS though. When my Stromer says 10% left does that number really mean 10% of the battery or what the engineers designed and equate to a safer number on a battery say 25% of a non BMS battery?

Mark

All batteries sold by a bike manufacturer have a bms.. And the low voltage cutoff saves the battery from damage. On my Stromer that last 10% certainly doesn't mean i have 10% miles to empty....That's why I try to avoid running it down that far.
 

Ravi Kempaiah

Well-Known Member
Yes, one of the material aspects that lead to Li-battery degradation is the formation of SEI (Solid Electrolyte Interphase) zone near the cathode. This builds up with usage and reduces the movement of Li-ion between the electrodes. High voltage, over charging/discharging, extreme temperatures accelerate the growth of this "wall" and thereby diminish the capacity.

Recently, Scientists at Brookhaven National Lab have successfully tracked the SEI formation in real-time [ or capacity degradation] and more data can be found here.

http://www.bnl.gov/newsroom/news.php?a=24805
 
I have a lithium ion battery in my phone (Samsung note3) and I do exactly (from the first day I got the phone) wat court recommends in the first post in this thread. And my phones battery is incredibly strong and lasts me days of use in one charge. Or I use it like a lot in one day (as at work I sit around alot) playing on Internet and stuff and I will still have 40-50% battery life at end of the day. So I would do what court says . Just be mindful if it's done charging take it off the charger. DO NOT LET IT DIE ALL THE WAY EVER AS I DONT. I SHUT IT OFF AT 5% LOL
 

Court

Administrator
Staff member
Yes, one of the material aspects that lead to Li-battery degradation is the formation of SEI (Solid Electrolyte Interphase) zone near the cathode.
Great information Ravi! Thanks for providing the scientific background on how and why battery breakdown occurs. I've heard that with all batteries even if you keep them in ideal conditions, charged and don't even use them over time the electrons will dissipate and the battery will die. Have you heard this?
 

calvin

Active Member
Great information Ravi! Thanks for providing the scientific background on how and why battery breakdown occurs. I've heard that with all batteries even if you keep them in ideal conditions, charged and don't even use them over time the electrons will dissipate and the battery will die. Have you heard this?
Self discharge rate for lithium ion batteries is 2 to 3 percent a month.... from Wikipedia: http://en.wikipedia.org/wiki/Self-discharge
 

Ravi Kempaiah

Well-Known Member
Great information Ravi! Thanks for providing the scientific background on how and why battery breakdown occurs. I've heard that with all batteries even if you keep them in ideal conditions, charged and don't even use them over time the electrons will dissipate and the battery will die. Have you heard this?

Sorry, court.
I somehow missed this.
I'll check with my friends about the phantom discharge. One of my friends thesis is about different types of anodes for lithium batteries and their lab is full of such stuff.
 

FitzChivalry

Active Member
One thing to keep in mind is that the 1,000 (or however many) cycles that a battery is warranted for doesn't mean the battery is useless at that point. It just means that it will charge to only (I believe it's) 90% of its original capacity. Considering that I draw about 60% of my battery's capacity each way on my commute, I anticipate getting a lot more than 1,000 cycles out of my battery. It's only when I can't get all the way to work that I will need to replace the battery; my work commute is the longest ride I take my bike on, at 21 miles.
 

calvin

Active Member
One thing to keep in mind is that the 1,000 (or however many) cycles that a battery is warranted for doesn't mean the battery is useless at that point. It just means that it will charge to only (I believe it's) 90% of its original capacity. Considering that I draw about 60% of my battery's capacity each way on my commute, I anticipate getting a lot more than 1,000 cycles out of my battery. It's only when I can't get all the way to work that I will need to replace the battery; my work commute is the longest ride I take my bike on, at 21 miles.

You ride your bike more than most of us. Perhaps you would be willing to write an extensive, detailed review of your bike and give us the particular and general knowledge you have gained. This is something I have considered doing instead of just interjecting bits of info into the forum.
 

Pos

New Member
Sudden Power Cut

Sudden power cuts on a steep hill with the Phantom X2 can be scary.

I have had continuing problems with the PhantomX2 bike's battery and it is still just under the two year warranty. Since it was a little over a year old, the battery suddenly lost power and has been sent back to Prodeco twice, once to check and another time to replace the split plastic case. The service department has sent fuses, replacement controller, new rack and wiring.

I fully charge the battery before riding.

After riding for about 38 minutes of cycling under power and a distance of 9.5miles on a flat road, I get a power cut. The times and miles will vary each time I ride the bike. However the LED readout on the battery pack would read one green and one red light which I presume to be about half capacity left.

The specialists at the bike shop told me that the LED readout is not reliable. they did suggest that the battery may have a defect.

For the record I have fully documented the problems of this bike with the Repairs department at Prodeco but I fear that when the two year warranty runs out in November, Prodeco may not honor any repairs or replacement of the affected part(s) if any.

I would appreciate your suggestions? Battery drain?

Time to change to another brand?