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Discussion Starter · #1 ·
All forms of batteries seemed to be adversely affected by Cold!

Very noticeable, especially on my various ebikes, was that, cold greatly reduced the rate of output, as well as the capacity of various types of batteries.

This degradation is common to both Li-ion, as well as SLA batteries. Based on complaints, from others, LiFePO4, Li-po, Nimh etc. seem to suffer similarly.

The "rate of output" is often designated as the "C" rating. For example a 30ah battery, capable of a 30 amp output, would have a rating of 1C, a high performance RC car battery, (Li-po), might be a 5ah 20C rated, thus capable of a 100amp output, of course it would empty, very quickly!

Sub freezing temperature might cut the C rating, as well as the overall capacity by 50%. 0 degrees Fahrenheit degrades considerably more!

In my experience, most of this degradation is due to the battery temperature, though the cold motor and drivetrain also contribute, somewhat.

My recommendation is that the battery should be kept warm.

Easiest would be the use of a water heater blanket, to maintain ambient heat.
 

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Discussion Starter · #3 · (Edited)
Eco terrorist ... not!

Why do you hate the environment? ;)
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?
........................... ?......................
 

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Discussion Starter · #5 · (Edited)
Battery Improvements!

That was a joke. I just think it's silly that someone would go to the trouble of trying to keep their batteries warm. Just ride.
How could you possibly think it is a joke, to claim a person hates the environment, because he is trying to make batteries more efficient?
 

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Discussion Starter · #6 · (Edited)
eVehicle technology!

That was a joke. I just think it's silly that someone would go to the trouble of trying to keep their batteries warm. Just ride.
Batteries, being warm, increases your range by between, possibly, 50 and 100%+.

Most noticeable is if I leave my bike, or battery outside, while at work.

Partial solution is that I carry my Li-ion homemade packs in one of those insulated-waterproof lunch bags. I just unplug, and carry inside with me, (25.9v 31.2ah weighs about 9lb.) Typical non-pedal range is between 20-40miles per charge. Pedal assist range varies by speed, 16mph 100++ miles, 20mph possibly 50miles+. Full charge top speed is 22mph+, (on this modded bike.)

Actually the severest complaint about electric cars is how drastically their range is reduced by cold weather. On eCar forums, I've recommended, insulating the batteries, combined with the use of the common, water pipe, thermostatically controlled heat tape. Which would keep batteries warm during charging, pointing out, that a battery powered 100w heat tape could keep the battery warm, sitting outside for a full, cold, workday, using only 2% battery capacity while increasing usable battery output by, possibly, 100%.

At this time, I view eBikes as testbeds, or prototypes, for the technology that could be employed in larger eVehicles. I soon will be producing eTrike conversions as "mobility devices" for handicapped, or old persons, hopefully bypassing NY State anti-eBike stance. (Using the Schwinn Meridian, hanging heavy SLA batteries below the rear basket should increase stability substantially and leave room for groceries etc.) Hybridization will be possible! I have a 53lb 1500w 4-cycle generator capable of supplying 600watts for 12 hours on 1.5gal gas. Just drop the generator into the rear basket, plug-in and "long-haul" it. (1200w continuous should motivate at well past 30mph)

This will be my Stage 2, eBikes being my Stage 1.
Prototype should be ready by Spring.

Some people might be concerned by my use of "possibly", "probably", "likely". I have a "scientific" mind, absolutes like, positive, absolute, need, rarely exist, else we might still be living on a flat Earth.

I view "certainty" to be a crutch for the narrow minded!

Hmmm .. Maybe ... it's just my ex-wife, constantly yelling, "And that's just all there is to it!", in my ear ...
 

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Two skinny J's
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Hack.....go to your room....close the door and don't come out until we tell ya to! AND leave your puter out here with us. No innanets for you.
 

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Discussion Starter · #9 ·
Simple test.

Just performed a basic comparison between 18650 Li-ion at 30* and 60*. Using the same 380 lumen LED flashlight, 30* output was 1.2 amp, 60* output was 1.4 amp. That is almost a 20% reduction caused by a 30* differential.

Test was conducted using 2 batteries that tested the same output at room temperature, then one was set outside for an hour to chill.

Would have tested a wider range but was too warm today, and no freezer at work.

* = degree Fahrenheit (closest keyboard option)
 

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Discussion Starter · #10 · (Edited)
Battery Pack Warmers!

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.

I would like to apologize, to the "decent" members of the forum.
Recently the unchecked bullying, on the forum has upset me to the point that I will no longer sit back and take it.
So I have become pro-active in the effort to attract attention to the problem.
My step #1 was to make sure the Mod was aware.
Step #2 was to point out that such activity, made the entire forum, a place where decent members ... would rather not be.
Step #3 since bullying seems to be the accepted behavior, I have engaged in a bullying campaign, against the bullies! Just demeaning their intellect, lack of reasoning etc.
Sadly, (I almost feel sorry for them), when pressed, they tend to shrivel up, and fall back on their infantile vulgarities.
Which does seem to attract enough attention, to get them censored, warned, or banned!

A simple show of support, would be to click on the "report" button of any post, that you deem "objectionable", and of the type, you don't believe should be allowed on this forum..


Feel free to quote this "notice".
 

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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
 

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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.
 

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Discussion Starter · #13 · (Edited)
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
 

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Discussion Starter · #15 · (Edited)
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.
 

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Discussion Starter · #17 · (Edited)
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 ...
 

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Thats correct, i have done alot of research and development in the battery industry.....no matter what type of battery you have, the cells and chemistry has a peak performance temperature.......thats science for you!

There are some ways to change the Peak to a lower temperature by adding additives to the cells electrolyte.
 
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