[Mark_w]

Thanks for sharing the information. I find it difficult to run a full "battery" of tests myself, so community testing is awesome.

I found the same effect from cold on my SLA batteries. I do find that when I keep the battery indoors and put them on my bike just for the ride, the huge thermal mass keeps them warm for most of my 30 minute commute. Then I bring the battery inside to re-warm during my work day.

I'll be testing the range of my LiFePO4 at some point, but the 25 mile range is way beyond my commute. Therefore I need to set aside an hour of ride time.

Ride-on

[froze]

Originally Posted by ViBiker

How do I "Hate the environment"?
Because I prefer electric vehicles over gasoline?
Because I recycle used notebook batteries into electric bicycle batteries?
Because I prefer Li-ion, the environmentally safest and most profitable to recycle, type of battery?
Because I advocate extending battery efficiency and use into the colder environs?
........................... ?......................

You recycle used notebook batteries into bicycle batteries? How do you do that? All my laptop batteries are so close to death by the time I replace them they wouldn't be of any use for an electric bicycle.

And Li-Ion bats are far from be environmentally friendly; read this: Environment - Environmental Technologies Action Plan
And cobalt, which is used in Li-ion bats is very hazardous to the environment. And it takes about 9,000 tons of cobalt to manufacture those bats EVERY YEAR!! What do you do with your bats once their completely useless? take it to a recycle center? Guess what they do with Li-ion bats? They take them to landfills because the recycled value is only $100 a ton which it makes it completely worthless to recycle; and American landfill rules don't prohibit it! So about 2 million Li-ion bats are being dumped into landfills each year. See: Lithium ion batteries: High-tech's latest mountain of waste - Computerworld Blogs

It would be better off to have a small gasoline motor on your bike instead of these damn hazardous Li-ion batteries.

[ViBiker]

Originally Posted by ViBiker

Everyne knows that cold degrades your batteries performance.

Solutions?

Insulate your pack.
For Li-ion, LiPo, LiFePO4 etc, insulated lunch bags, 6pack coolers etc, provide nice thermal protection.
Pre-warm your pack.
or ... add heat packs, gelled preferred, liquid might not be recommended!

Keep your battery packs warm.
Low wattage pads, in conjunction with insulation, should perk up your batteries, cold weather performance!

Found a nifty little item that might be the best-cheapest solution!

All Sold>12v Flexible Adhesive Heatpads $5.39/pair

New Link>12v Flexible Adhesive Heatpads $5.39/pair

Another Link>12v Flexible Adhesive Heatpads $5.39/pair

Another Nother Link>12v Flexible Adhesive Heatpads $5.39/pair

Inexpensive, thin, flexible, self adhesive, low wattage heating pads.
Low wattage ... add as many as necessary!



Will run preliminary tests with separate power source, 3S Li-ion. To measure drain & performance increase.
Note: Should run nicely at 2S, or 1S, for less heat output! 4S, for more?

Ordered a few pairs, from China ...
But might take a couple weeks ... will post review, as soon as possible.

Received "Heaters" ... 11 days shipping time.
Comes with full size dbl sided adhesive tape.
2 pads run in parallel use 1.2A
12V x 1.2A = 14.4 watts
8V x .8A = 6.4 watts

Rigged in series
12V x .3A = 3.6 watts

[billjohnson]

Solution live in the north in the summer and the south in the winter, thats what I do.

[ViBiker]

More test results:
2 pads run in series:
25.9V pack - 29V
.7A 1- 13.5V 1- 15.5V = 20Watts ... 15.5V noticeably warmer ... too hot?
Reversed voltage showed same pad running at higher V.

3 pads run in series
.5A 8.6V 9.1V 10.7V = 14.5Watts

25.9V pack - 29.2V
4 pads run in series 25.9V pack - 29.2V
Covers the main exterior surfaces of my LiPo packs.
All pads near 7V - about 3W each
Looks to be ideal for me, with batts placed in insulated pack.

37V pack - ~42V 6pack "Cool Cell" pack should work nicely with 6 pads in series.
(6 pads covering vertical surfaces nicely.)
Stats should be nearly identical to 4 pad 29.2V pack.

[uumotor]

I support for the electric bikes, the will be better for our environment. Let the earth more green...

[ViBiker]

Now this was a sad excuse for a Winter!
Upstate New York, just below Buffalo ...
Usually we get 100-200 inches of snow.
Last Winter? About 300"!

This Winter ... less than 1 foot! Maybe 10"?
Had to scrape off the sidewalk 3 times, less than 3", each time.

And it weren't cold enough to even bother trying my heat pads.

The good news?
No "Spring fever".
When we had 60+ degree weather in February, it kinda' knocked the edges off cabin fever. Biked about 80 miles one day ... got sunburnt too ...