Deep Cycle Gel life reduction in Snow...

[Mattaus]

Right then...it snow's a hell of a lot more in the United States/Canada/Europe than it does here in Australia so I figure someone here might have the experience I require.

A few friend's and I are going snowboarding during our winter in mid July. I have built a triple XM-L flood light (and will be building 2 more) to allow for some night riding.

However as we all know battery life dramatically reduces with reduction in temperature. With flash light batteries keeping them warm, or warming them up, is not a problem. It's just a little hard to do with a 105Ah Deep Cycle Gel Battery!

What would our best option be to keep the battery as warm as possible? Keeping it in a car, with the leads running outside to and from it may not always be an option. I was thinking something along the lines of a small insulated box?

Has anyone seen this, or have any experience with the issues we will have?

Your thoughts and comments would be greatly appreciated.

Regards,

- Matt

 

[onetrickpony]

Well, I live in the northeastern us, and we don't take any special care of our car batteries at all, so I think you'll probably be ok as long as you don't really discharge it too far. If it has a charge, it will take the cold, if it's dead, the cold will damage the battery.

How long are you planning on using it without charging it?

 

[Mattaus]

Well we have access to the genset so we can charge it once it approaches 50% capacity (our aim) but that been said, gensets are banned where we're heading so if we can't we'll try not to use it after 50% jut to preserve it's life. It is borrowed so it's kind of rude if we don't!

I guess what I need to ask, is won't the battery discharge faster in the cold? You hear about devices not lasting as long in the cold because of the reduced battery life...

 

[Battery Guy]

I guess what I need to ask, is won't the battery discharge faster in the cold? You hear about devices not lasting as long in the cold because of the reduced battery life...

No, the battery won't discharge faster in the cold. However, it might appear to discharge faster because the voltage will drop faster at cold temperatures because the internal resistance of the battery is higher.

Whether or not you need to keep the battery warm depends on your drain rate. How many amps are you planning on pulling from this 105 Ah battery? If your current requirements are low (<20 A), then you probably do not need to worry about keeping the battery warm.

Cheers,
BG

 

[Mattaus]

1x 2.4A floodlight and 2x 3A floodlight. So 8.4A total at any one time is the plan. Much lower than 20A so we should be good then?

 

[Battery Guy]

1x 2.4A floodlight and 2x 3A floodlight. So 8.4A total at any one time is the plan. Much lower than 20A so we should be good then?

You should have absolutely no problems with an 8 A discharge on a 105 Ah deep cycle lead acid battery at temperatures around 0 degC.

 

[Mattaus]

You should have absolutely no problems with an 8 A discharge on a 105 Ah deep cycle lead acid battery at temperatures around 0 degC.

Sweet. Thank you very much for clearing that up. Appreciated!

 

[jayflash]

Ordinary wet-cell vehicle batteries rarely indicate Ah capacity while their cold-cranking output ranges from ~500 - 1000 amps. Given the physical sizes of "car" batteries, could one expect a range of ~75 - 120 Ah for normally available sizes?

Is "reserve" capacity, rated in minutes, a standard combination of voltage/load/temperature? If so then one could calculate capacity. Thanks for any info.

 

[shadowjk]

40-80 is probably typical for normal cars. Higher range for diesels.

 

[Mattaus]

Traditional Car batteries: short term high amp drain. Immediate recharge.
Deep Cycle batteries: long term low amp drain. Infrequent recharge.

They are designed different as far as I understand it, though both could maybe do a reasonable job at the same tasks?

Anyway – my mate happens to have found a battery case for the deep cycle we are using (he already owned it but forgot about it). We’re going to use it to minimise the effect of wind chill, even if it is a totally fruitless idea.

Question – if we were line the case to add a bit of insulation is there some thing we should use in particular? Inversely is there anything we should avoid?