Battery Vehicle Society

Hi,

I was thinking of taking an electric vehicle overseas, but am aware that lead acid batteries don't like it too cold.

Does anyone know how cold would a winter has to get to cause proplems?

cheers
mab

To be fair anything around 10C starts to make LA's sluggish 5C and they get pretty hacked off , to be fair the warmer you keep them the better off you are, of course you could beat the cold with battery warmers and then it dosnt matter how cold the outside is if you have your batteries cooking nicely at about 25-30C

ChrisB

My first winter in the Scottish Borders saw my range nearly cut in half! The cold hits lead very hard because the voltage they can deliver tends to be lower. This then means you have to pull more amps for the same performance and so leads to a snowball type scenario. Lower voltage, more amps which lowers voltage even more, etc...

It wasn't a problem for me because I was only down to around 50% DOD in the summer. But that was closer to 80-90%DOD during the winter which I suspect was quite hard on the batteries.

Consider some insulation and batttery warmer for cold weather, or Lithiums!

Greg

Check these people out, they are experts in running EVs in cold climates -
( Canada )


http://www.revconsultants.com/

How come ICE starter batteries seem to do fine in the cold? It can get down to -20C here in the winter and I've never had a problem with starting...

Is it just that I don't notice the difference because it doesn't take that much from the battery anyway?
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Ed

Two reasons: SLA batteries (starter/lights/accessories) batteries as used in cars have a different mechanical and chemical makeup to traction batteries; and secondly, you use the batteries differently in starting a car to driving an electric vehicle.

SLA batteries have an easy life. They never get discharged - if they go below an 80% state of charge they think they're getting it hard. So they'll spin around a starter motor quite happily on a cold morning, because they only get a five to ten second hard drain and then they get charged up again.

It's a bit like getting out of bed in the morning, doing twenty press-ups and then getting back into bed and having your other half bring you a nice hot cup of cocoa, the morning papers, plumping up your pillows and handing you the TV remote.

Traction batteries, however, have it tough. They'll give pretty good performance when they're fully charged, but a few miles down the road they start suffering when it's cold.

I've bought myself a 12v electrically heated blanket. I'm having silly thoughts about using solar panels to keep the batteries warm in the winter, to stop them getting too cold in the first place.

Thanks for the explanation Mike, I like your illustration =o)

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Ed

It works -- using some of the battery to heat the others up - yeilds longer range

go over the top with insulation - try and find away to get motor heat to the batteries - also look at way to get the heat from brakes o the batteries

you could install your own induction braking system alongside current system - wired to a heating coil