The cold got to my Pro Connect.

[flecc]

Just out of interest is the reduction in capability the same across battery technologies ie is there any difference between how NiMh and LiIon are affected by cold weather?

All battery types suffer in the cold, you may be familiar with the difficulties motorist often have in starting cars in severe cold with the starters struggling to crank engines due to limited current supply. In extremely cold climates large diesel engines sometimes have cartridge start, a method where a fired shotgun cartridge drives an impeller on the crankshaft.

The reason batteries don't perform well in the cold is that they are chemical devices, and chemical reactions need heat to be efficient. In general batteries work best between 20 and 30 degrees C. There are some variations between battery types, but the general principle of needing heat remains.
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[johnp]

Cold battery

Did a 21 mile run on my Salisbury LPX in same conditions, averaged 14.8mph, so was certainly using the battery. Still plenty of life (2 out of 3 lights).

Although I have not done a range test in warm weather on my new bike I have been out 4 times this week and covered between 21&28 mls each time and still have the three lights on on return home (bike Diamond eastwood motor Tongxin battery 8amp all up weight 94kg).
I cant wait for warmer weather to do a long range test,on my mark 1 torq I can travel 28 to 30 mls to see the red light.


JOHN

 

[prState]

Here's a suggestion (from treating sports injuries and the like)

Get a small cloth towel, or rag, wet it, and microwave it a couple minutes.

It will be blazing hot (or less depending on what you want). Then drop it in a large plastic bag and seal it. You could probably drape it round the battery 30 minutes or so in the morning, which should be enough to warm it up significantly.

You can also heat it in the plastic wrap or bag, though you might want to make sure it's not absolutely air tight. Only thing, if you have a an opening make sure it can only leak out below the battery, rather than over it.

Of course, if you take the pack off the bike, laying a warm compress over it would be all the more easier, I'm sure.

 

[flecc]

Of course, if you take the pack off the bike, laying a warm compress over it would be all the more easier, I'm sure.

Many soft cell types in use now lose heat very quickly, so warming initially is only productive for a very short while. The illustration I showed above is of this type, just the thin plastic battery case and thin soft cell bag material separating the active content from the cold.
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[moon]

Reading this thread makes me think that batteries should have some kind of heating system installed for winter riding, otherwise electric bikes become fairweather machines.

This would drain the battery a bit but it would also be more efficient as a result??

 

[flecc]

Reading this thread makes me think that batteries should have some kind of heating system installed for winter riding, otherwise electric bikes become fairweather machines.

This would drain the battery a bit but it would also be more efficient as a result??

Most electric heating is quite inefficient, and the current required to oppose zero degree temperatures would very rapidly drain the battery and wouldn't produce anything like enough compensatory gain.

Chemical heating of the type used in self heating food cans would be light and practical, but it would require the two chemicals required to be preloaded every trip.

Combined motor and battery units like the Panasonic one could have the motor encased in an insulating case with light fan assisted recirculating warmth from the motor supplied to it's battery casing, and that would use no appreciable current and also give a gain to the motor efficiency in running cooler. The two gains in the battery and motor would be small, but they would be virtually cost free and easily designed in. A "summer/winter" manual setting control flap would have to be incorporated to prevent the warmer air from the motor supplying the battery when the weather wasn't cold, venting outside instead.
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[andyh2]

Hey Flecc, how come Panasonic aren't employing you on a consultancy basis

 

[flecc]

Hey Flecc, how come Panasonic aren't employing you on a consultancy basis

Nice idea, but the Japanese are proudly independent designers these days, in stark contrast to their pre-WW2 days when copying was the name of their game.

In 1930 they started their motor industry by stripping an Austin 7 and copying it to produce the first Nissan ever. Oddly enough, the latest Nissan model, the Qashqai, was designed in their Paddington, London design centre, had it's development proving in Surrey and was then initially exclusively manufactured at Sunderland before another production line was added in Japan.

As they've come full circle for cars, there's hope for me yet if I live long enough!
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[wotwozere]

Flecc

WOW I did it and my Battery lasted 2 days instead of only 3 legs of the journey.

This bike have truly changed my life.

thx Bob