Cold Weather and SLA batteries

[USAEBIKECO]

I was testing my new custom folding bike and noticed 5 minutes into riding the power dropped. I was going 22mph thn suddenly dropped to 16mph. Here in chicago it was 20 degrees with the wind chill. I still rode for 8 miles at 16mph.

SLAs is pretty tough but how does li-on batteries do in the cold?

 

[liveforphysics]

Like all batteries, Lithium cells in the cold also take a pretty hard hit in both internal resistance, capacity, and even resting voltage drops a bit.

But it would take liquid nitrogen to get a LiPo battery to perform as badly as a warm SLA on it's best day.

 

[AussieJester]

But it would take liquid nitrogen to get a LiPo battery to perform as badly as a warm SLA on it's best day.

Dont hold back Luke tell us how you really feel about SLA buddy hehee

KiM

 

[Solar Motion]

This chart is posted next to our battery bank, which is vented outdoors for equilization charges (the smell is really something). Colder temperatures have a big effect on capacity. 100% at 77deg F, 80% at 32deg F, 50% at -22deg F and so on. I'm also using SLAs for the E-Bike.

Link to page: http://www.windsun.com/Batteries/Battery_FAQ.htm#Temperature Effects on Batteries

 

[davespicer]

Link to page: http://www.windsun.com/Batteries/Battery_FAQ.htm#Temperature Effects on Batteries

That whole FAQ page is a keeper. Thanks!

 

[Affliction]

I was testing my new custom folding bike and noticed 5 minutes into riding the power dropped. I was going 22mph thn suddenly dropped to 16mph.?

Sounds to be you have 1 bad battery in your pack. It would have less capacity and discharge faster than the rest. Thus the sudden drop in power.
partially discharge the pack and look for the battery with lower voltage than all the rest, that will be the culprit.
I know everyone hates sla's but they can take alot of abuse without immediately destroying themselves and they are way cheaper than lithium

 

[Russell]

If you start with a battery at room temperature then go out for a ride it takes quite a while for it to cool down so capacity isn't going to be affected all that much. If on the other hand you store your battery out in the cold you will suffer a significant loss in capacity and that goes for LiFePO4 as well. Here is a capacity Vs temperature chart I got from a Fusin Battery spec sheet for their prismatic cells.




-R

 

[Affliction]

If you start with a battery at room temperature then go out for a ride it takes quite a while for it to cool down so capacity isn't going to be affected all that much. -R

Americans don't know what cold is about! Try running your bike at minus 40 degrees! I wear a full skidoo suit for most of the winter here.
The battery capacity is greatly affected in a few minutes.
I park my ping battery for the winter because I use alot more current to drive through snow continuiosly than a bms would allow.
I'm awaiting a new set of 10.5 ah Powersonic batteries for my winter travells. Should be here in a week.
Ya they are sla's but I can abuse them at 60 amps continuous current output.
Yup this adds to the stereotype... ***edited***.

I rode my ping in the cold and it crapped out quickly; I have a bms bypass but that is for emergencys.
The praise of lithium batteries is FAR overstated! they are useless in extreme cold weather.
I'm using sla for this reason. ***edited*(****

 

[Russell]

If you start with a battery at room temperature then go out for a ride it takes quite a while for it to cool down so capacity isn't going to be affected all that much. -R

Americans don't know what cold is about! Try running your bike at minus 20 degrees! I wear a full skidoo suit for most of the winter here.
The battery capacity is greatly affected in a few minutes.
I park my ping battery for the winter because I use alot more current to drive through snow continuiosly than a bms would allow.
I'm awaiting a new set of 10.5 ah Powersonic batteries for my winter travells. Should be here in a week.
Ya they are sla's but I can abuse them at 60 amps continuous current output.
Yup this adds to the stereotype***edtied***
I rode my ping in the cold and it crapped out quickly; I have a bms bypass but that is for emergencys.
The praise of lithium batteries is FAR overstated! they are useless in extreme cold weather.
I'm using sla for this reason. ***edited***

Apparently you are confused by the Fahrenheit scale we use in the USA but I can assure you it gets cold here, in fact the extended forecast for the next two weeks shows a range of 2C to -12C here in the warm part of the state.

Anyway it does indeed take quite a while for a battery stored at room temperature to cool off to where capacity will be greatly affected. Also many people like me have our batteries in bags or enclosures of some kind often with foam padding around them which insulates them. Furthermore batteries generate heat in use which helps keep them warm.

One also one has to separate the battery capacity in cold temps from the distance one can ride in cold temps on that battery. In cold temps I find I use more power for a host of reasons such as; I do less of the work in cold temps because I don't want to breathe the cold air in deeply, I wear bulkier clothing which adds to aero drag and even things like increased air density and stiffer bearings affect the power used. So far however I haven't noticed any significant drop in capacity though I haven't ridden yet under 2C. Maybe on a nice frigid day I’ll toss in my small battery pack and do a capacity test in the name of science…if somebody doesn't beat me to it.

Ypedal (one of your smart Canadians) did conduct this test where he started with an E-BikeKit battery at -7.5C and got roughly 7.5Ah or 75% of the rated capacity. His test of this prismatic cell battery correlates closely with the Fusin cell data I posted in a previous post above.

http://www.endless-sphere.com/forums/viewtopic.php?f=4&t=8452&start=75#p143566



Finally, please make an effort to lose the attitude


-R

 

[liveforphysics]

You can't use the performance of a ping pouch to represent LiPo... Aye

 

[dequinox]

I tend to keep my SLA pack indoors while charging and not in use. I have about a 5 mile ride in our cold mornings ( about 30f), but my pack doesn't really drop in power until I ride it out to 8 miles...even in the cold. I think the reason is that they are warm to start with, heat themselves slightly due to internal resistance, and are well insulated in my trunk pack.

I had the idea to use these to keep my batteries warm when I go LiFePO4:
http://www.walgreens.com/store/cat...frgl_474339&ci_src=14110944&ci_sku=sku6007247

8)

 

[Affliction]

Apparently you are confused by the Fahrenheit scale we use in the USA but I can assure you it gets cold here, in fact the extended forecast for the next two weeks shows a range of 2C to -12C here in the warm part of the state.
Finally, please make an effort to lose the attitude
-R

***edited****: -40c is the same temp as -40Fahrenhiet. and I'm confuzed?
-12c is swimsuit weather here up north
At -40 roadsalt stops working to melt the ice and they start using sand on the roads.
It's so cold it hurts to breathe!
The rest of the world has gone metric but americans ***** have chosen to stay imperial measurement.
****edited***A little note about cold.... We have a Russian supercapacitor in our electric club for testing.... You know what it was used for?
It is so frikkin cold in russia that batteries are useless! A couple russian soldiers would hand crank a generator to charge the supercapacitor so they could start their russian tank!

 

[Affliction]

I tend to keep my SLA pack indoors while charging and not in use. I have about a 5 mile ride in our cold mornings ( about 30f), but my pack doesn't really drop in power until I ride it out to 8 miles...even in the cold. I think the reason is that they are warm to start with, heat themselves slightly due to internal resistance, and are well insulated in my trunk pack.

Shit! $30 for 40 of the things! It would be cheaper to get some electric socks!
http://www.thunderboltsocks.com/

 

[Mike1]

Yup ***edited*** -20c is the same temp as -20Fahrenhiet. and I'm confuzed?

-20C = -4F

-20F = -28.9C

 

[Affliction]

Sorry I forgot, -40 celcius is the same as -40 Farenhiet.
I knew I seen the thermometer at my grandparents place in quebec when it was -40 outside.
I forgot what cold was, global warming and all LOL!

 

[auraslip]

LoL @ this thread

I watched my ping pack dip down to 49 volts, an all time low, the first night I got down in the 40s. I had to plug the "forced air cooling vent" on my battery box for the winter.

 

[grindz145]

At -40, you're in mil-spec range electronic components (though they don't really call them that anymore). You have to oversize your pack for winter no matter what you're using. The cells that do better at lower temperatures are usually those with higher internal impedances (like LiCo) because they heat themselves up with current. This is usually a bad thing but in this instance it actually helps out. I've seen batteries with bad tab welds perform better than batteries with good tab welds at -30 and it took me a little while to figure out why

 

[texaspyro]

Even LiFePO cells are severely affected by even moderate cold. About half way down my the first post in my thread http://endless-sphere.com/forums/viewtopic.php?f=14&t=20698&start=0&hilit=and+other+effects are some plots of A123 cell performance when they were popped in a freezer at 5F then removed and discharged. The effect is rather dramatic...

 

[lifepo4ever]

we almost in 2011 and people still use sla :lol: :lol: i even know its still exist :lol: :lol: i run lipo on ebike at -20 and i don't have problem at all because everthing is in plastic case , the heat génerated by the controller and lipo build a confortable environnement for all electronics

 

[lifepo4ever]

summer time the controller will go on the top of the case and its take 10 minute to swap there with the bolt

 

[USAEBIKECO]

Some customers dont have the money to run lipo. Were still in a recession SLA can still get the job done. Some customers simply want a standard electric bike that can get them to work without gas.

 

[lifepo4ever]

sla kill the range of ebike i never have sla even in my first set up if you going to keep the same set up for 5-6 year its better go with lithium because
you have to change your sla battery every 100 cycle if you lucky you may have a little more so you save nothing because you have to buy every year new battery
if you use sla 2-3 time a week you good for 2 year if you lucky so again if you need everyday your ebike for saving gaz you never get more then one season on sla . I am not rich and just wait to keep money to buy something will last longer then have somthing with poor performance , i also live in apartement and never i will climb the stairs with 60 pounds of sla + the bike , lipo are now very cheap its cost you 200$ for 36 volt 10ah http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=14609 even ping battery is only 300$ for 36 volt and will last 7 years

 

[oldpiper]

Well, I know it's almost 2011, and I'm using SLA's. I converted my bicycle because I didn't want to drive my short commute any more, I couldn't see adding $200-300 to the cost because it would take even longer to break even, and the almost no maintenance of an SLA appeals to me.

Now, since I only see a shallow discharge each commute, I expect to see multiple years out of the batteries. There's gotta be a reason Sears warranties their DieHard (lead-acid) auto batteries for 5 years, and it's not that they have to get replaced every Fall, I don't think.

Cameron

 

[lifepo4ever]

Well, I know it's almost 2011, and I'm using SLA's. I converted my bicycle because I didn't want to drive my short commute any more, I couldn't see adding $200-300 to the cost because it would take even longer to break even, and the almost no maintenance of an SLA appeals to me.

Now, since I only see a shallow discharge each commute, I expect to see multiple years out of the batteries. There's gotta be a reason Sears warranties their DieHard (lead-acid) auto batteries for 5 years, and it's not that they have to get replaced every Fall, I don't think.

Cameron

ok man if you don't have choice use your sla and I don't judge nobody here because they choose SLA its was a opinion of what I read in the forum past years you not the only one using it ,

for you die hard battery they are larger capacity first and its take lot of time to kill the cells because of the bigger capacity they suffer less so don't compare your small size sla 12ah to a big die battery because when you start a car you use the current for about 3 second so they have no time to have stress and also the alternator is there also to help that why the battery have a extended life , and nobody want to ride with a 40 pound battery with a single 12 volt battery imagine if you need 36 volts you will need a trailer to pull 100 pounds of car battery

don't forget the recharge every time you finish your ride with your sla because more you waiting for recharge them more you kill the cell

for the last word sla sag is day and nite with lithium its what I heard for lot of ES members

 

[auraslip]

lipo are now very cheap its cost you 200$ for 36 volt 10ah http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=14609 even ping battery is only 300$ for 36 volt and will last 7 years

IIRC don't lipo have a 400 cycle life?

Also when you account for the fact that lipo aren't plug and play, yet, it makes it an unreasonable solution for commuters. For Lipo to work you must have a pretty good knowledge in the hobby, and a couple hundred dollars in equipment.