battery range in colder weather

[fishingpaul]

i seem to remember reading somewhere of lower distances in cool weather, my usual 4 round trips is dropping to 3, could this be attributed to colder weather, and driving through leaves and mud, or is my nimh battery dying.

 

[flecc]

Could well be the colder weather Paul, the Li-ion I've been using successfully on my Q bike until this week has cut out two days running on the usual trip, and the standard NiMh I used instead today turned in a fractionally lower speed on a familiar stretch, indicating the voltage down a bit.

Batteries hate the cold, and having just seen the forecast, it will probably be a bit slower again on Friday.
.

 

[Ian]

Most battery types don't perform as well in the cold, on a few cold occasions I've had to warm digital camera batteries in my hands to make them work. Try keeping your battery in a warmer place prior to use , or charge it just before using it so that it is still warm from the charge. Once in use the heat generated by use should maintain a reasonable temperature. If all else fails give it a woolly jumper.

 

[rsscott]

On my Torq last winter I found the most important factor in getting a decent range out of my battery was to ensure that for the first 2 miles or so, I did not use full throttle at any time. I would cruise about 4-5 mph below top speed and put much more effort into pedaling.

 

[allotmenteer]

I got 16 miles out of my 36V 9Ah Ezee Nimh this morning (avg speed 18.6mph). Temperature was fairly mild 8 to 9C though. Tomorrow morning looks to be down to 3C, brrr!

 

[Beeping-Sleauty]

bbbrrr....

having noticed a range loss of some 40% on tuesday which was very cold, yesterday i warmed the battery for a couple of hours on my mantlepiece, this seemed to do the trick for my SLA, although once the bike had been running for 45 minutes or so the power dropped off dramatically... think i might need one of those heated sox for when it gets really cold. Didn't notice this last year, but have done about 2,000 miles since on this battery.

 

[JohnInStockie]

I have noticed a difference too. My normal commute of 10.5 miles to/from work leaves me with 2 lights left on the Twist, this week its been down to 1, and tonight on the home run, down to 1 flashing (which means its ready to die).

I think this is partly the weather, partly the 16T sprocket I've just changed to, and partly the fact that the batteries have been recharged about 250 times already this year (could they be in need of a revamp?).

 

[flecc]

No, I think it's just the weather and the 16 tooth John.

When I geared my Twist up a bit in swapping from the Nexus 3 to the SRAM P5, my range dropped from 20 to 17 miles immediately.

I was also doggedly riding in the cold today, but for mile and miles, repeatedly emptying two NiMh batteries as part of a different charger test. Still at least I was able to keep the twistgrip throttle at maximum all the time, even downhill, since all I wanted was the shortest range. I did manage to empty one eZee battery from full charge in just 8.4 miles on my worst case switchback route! Must be a record.
.

 

[JohnInStockie]

Talking of discharging your NiMh batteries, have you looked at the chargers on e-ride or bersonev. Are any of these any good for your purposes?

 

[flecc]

They might be ok John, but I usually use a specialist charger company, Powerstream, who have full data available on all their models, give good service and are sensibly priced.
.

 

[JohnInStockie]

Fair enough. 8.4 mils!! That is quick, how hard was it NOT to pedal, must have been infuriating.

 

[flecc]

Yes, it does need patience!
.

 

[allotmenteer]

I've just seen my local powabyke rider pushing his bike along the pavement. Looks like his battery may be giving less range in the cold weather. Poor bloke, that's not a bike I'd like to push. He must have had a minimum 2 miles to go as well.

 

[flecc]

Those are almost like pushing a motorbike. The weight has always put me off them.
.

 

[fishingpaul]

i had a sakura s300, which is the same as the powabyke shopper i think, and it was very easy to ride on the flat, much better than my suede, despite the extra 12 kilos in weight, i never noticed any drag from the motor.it got me hooked on electric bikes,sadly i felt silly riding it and it had little use,a bit too feminine looking for me.

 

[flecc]

Yes, that's the odd thing, being low geared they can actually be easier to pedal at moderate speeds than they are to push when dead.

Worst of all is pushing them up a steep slope though, then the weight hurts.
.

 

[DBCohen]

Li Ion Batteries in frosty conditions

Last night was the first really cold night we have had, where frost was evident when I mounted my steed for the morning ride.

I have been leaving my battery on the locked and covered bike outside since I got it in the summer, on the understanding from other posts that keeping it cool is a key strategy for maximising life. I normally charge it at work, ride it home and than back for the return journey the next time I ride in.

I noticed and expected decreased performance this morning, due to the near-freezing temperature. The more pertinent question - should I be dismounting and removing the battery inside the house overnight in frosty winter conditions?

David.

 

[HarryB]

Last night was the first really cold night we have had, where frost was evident when I mounted my steed for the morning ride.

I have been leaving my battery on the locked and covered bike outside since I got it in the summer, on the understanding from other posts that keeping it cool is a key strategy for maximising life. I normally charge it at work, ride it home and than back for the return journey the next time I ride in.

I noticed and expected decreased performance this morning, due to the near-freezing temperature. The more pertinent question - should I be dismounting and removing the battery inside the house overnight in frosty winter conditions?

David.

High temperatures are the enemy of li-ions but I cannot find any info that says they are damaged by frost. You will get better performance out of your battery if you keep in doors but it will last marginally less well. If you are really interested in longevity you should be charging your battery at both ends of your journey if at all possible.

 

[flecc]

Li-ions are safe down to zero degrees centigrade, and last longest when stored at that temperature, losing only 2% of capacity each year, about a tenth of what happens at ambient temperature. They must not be frozen though.

All batteries suffer large drops in performance as the temperature drops towards freezing point. I've just returned from a NiMh trip and dropped two extra gears to climb my hill with the same pedal effort as usual, showing the severe drop in the battery efficiency after only 4 miles in about 8 degrees C.

That's with a battery that was indoors overnight in a fairly cool room, and I find this only gives initial benefit for a couple of miles or so, the cold not taking long to drop the temperature of the battery. Maybe it needs a woolly overcoat with a hot water bottle in it.
.

 

[fishingpaul]

i always try and take my battery indoors, even carrying it from the bike shed into work, my thinking being that without the battery, it is far less likely to be stolen,and of little value.