Lost battery power in the cold

[Justme]

How much power does a battery loose when it gets down to -8c ish (our bank is outside in a wooden box)?

 

Over the last cold spell our bat would only last 1 day before needing charging up. Normally it runs for 3 (ok a slight increase in usage but not that much).

 

It has improved & will now last 2 days (and seems to still be gaining) but I'm guessing its had it, or has it?

 

Luckily I have found a supplier of good use forklift banks for sensible money.

[WJM]

I cant give a scientific answer, but my new batteries performed well below normal during the cold spell.

[blackrose]

How does this work?

 

I know that many chemical reactions including those that take place in batteries, will speed up as the battery gets warmer. So if the reactions are slowed as it gets colder what happens to the lost energy? Does it return when the battery warms up again?

Edited January 26, 2010 by blackrose

[paulcatchpole]

How does this work?

 

I know that many chemical reactions including those that take place in batteries, will speed up as the battery gets warmer. So if the reactions are slowed as it gets colder what happens to the lost energy? Does it return when the battery warms up again?

 

I'd guess the energy doesn't go anywhere, you just can't get it out at a low temperature...

 

PC

[Justme]

I'd guess the energy doesn't go anywhere, you just can't get it out at a low temperature...

 

PC

 

 

Which would explain why the bulk (and total) charge times were much shorter than usual.

 

Prob commensurate with the 1/3 of normal use.

 

They would get down to only accepting 5 amps after about 4 hours.

Normally it would get to about 15 amps after twice as long & then if doing an EQ or full absorb cycle be held there for 3 or more hours.

 

(15 amps is about 1% of bank size so I would say its FULL FULL)

[soldthehouse]

I have heard that cranking the engine over a dozen times then leaving for two minutes actually warms the electrolite up because of the resistance created when exctacting electrical current from the battery. when tried after two minutes the increase intemp of the electrolite increases the voltage, but i,m a joiner so what do I know...

[jelunga]

Batteries do perform worse in the cold. That is why most car starting failures are in winter, when batteries are cold and so cannot give the same performance as they would in warmer air.

Our battery charger, a Heart Inverter Charger, allows you to set up what kind of battery you have. Wet cell cool or wet cell warm, and gel cool / gel warm. The cold settings give a higher charge voltage in the acceptance phase to get more charge in.

 

So, if the battery was giving the same oooomph in warm and cold weather, I would be surprised. I the loss of performance is significant, then I would suspect the battery is getting to be knackered (a technical term I learnt in the Army).

 

Keith

 

PS When our buses do not start on a cold morning because of flat battery, then the attempt to start often warms up the electrolyte sufficiently so that a second attempt to start 3 or 4 mins later sometimes suceeds. I keep telling Workshops that they actually need new batteries but "deaf ears" is all they have when it comes to spending on new bits.

Edited January 26, 2010 by jelunga

[nb Innisfree]

Don't know if it's true but in Canada and perhaps other countries headlights are left on for 10 mins or so prior to starting in cold weather to warm battery and raise voltage.

[bag 'o' bones]

Cold weather - poor performance certainly makes sense.

 

Watched a program a while back - think it was Top Gear - when they placed a car in a big fridge to simulate severe minus temperatures. The electrical system soon packed up due to the cold - not enough latent heat energyaround for the electrons to flow if I remember right.

[twocvbloke]

Batteries, if allowed to discharge enough, become less acidic, and in cold weather that is below freezing can damage the cells by freezing, and when it comes to using it, the batteries are not working right. It could be the case here, the cells may have been damaged with ice formation with the batteries being left discharged enough to allow ice to form. Also, corrosion can take place if there is more water than acid, which cakes up the plates, leaving them functioning poorly...

 

Another thing, the misconception that batteries perform worse in winter, or are "killed" by winter is untrue, a worn battery can work fine in mild weather, but once the temps drop, the battery needs to work harder (thicker oil, electricals used more often, headlights on more etc.), and a tired battery will just give up the ghost, and the owner presumes the frost has got it...

 

Also, simple battery maintenance is a must, even maintenance-free batteries need maintenance (despite their name!!!), keep the cells topped up with distilled (not deionised) water, keep them charged and keep them warm (well, above freezing), they'll last a long time that way...

 

And just to prove batteries are easy to look after, I picked up a Halfords branded Yuasa 70A battery labelled "Maintenance free", upon testing it was "past it" in terms of just using it as it was, but checking it out, the electrolyte was pretty much gone, so I filled up the cells with 3cm of water (Deionised accidentally, but it's not going in a car!!!), charged it up again, and now it's delivering more amps than it was when I first got it in the house...

 

How tough is that?

[Harpic]

How much power does a battery loose when it gets down to -8c ish (our bank is outside in a wooden box)?

 

Over the last cold spell our bat would only last 1 day before needing charging up. Normally it runs for 3 (ok a slight increase in usage but not that much).

 

It has improved & will now last 2 days (and seems to still be gaining) but I'm guessing its had it, or has it?

 

Luckily I have found a supplier of good use forklift banks for sensible money.

 

Many years ago, my car's engine would not turn over one morning in the very cold weather. I removed the battery, took it indoors and allowed it to soak in a sink full of hot water for half an hour. When I replaced the battery, the engine turned over (and promptly started). So the answer would seem to be that a battery DOES lose its ability to deliver a high current when it's very cold. It has not lost any charge, but merely its ability to release that charge quickly.

You could try insulating your battery box with something like thick expanded polystyrene, perhaps.

[n.b.Goldie]

Don't know if it's true but in Canada and perhaps other countries headlights are left on for 10 mins or so prior to starting in cold weather to warm battery and raise voltage.

Although I cannot remember the exact details, I recall that the handbook for the Lada (Russian) car advised that the car's lights should be turned on for a while before attempting to start during periods of very cold weather.

 

Ditchdabbler

[blackrose]

These all sound like good reasons for a mooring with shore power and a nice float charge all winter (with an occasional bulk & absorption charge of course).

[blackrose]

Also, simple battery maintenance is a must, even maintenance-free batteries need maintenance (despite their name!!!), keep the cells topped up with distilled (not deionised) water, keep them charged and keep them warm (well, above freezing), they'll last a long time that way...

 

Are you sure about this? I've been using Carplan or Tescos deionised water which says "for batteries". What's the difference exactly?

 

Have I been using the wrong stuff all this time?

[barge sara]

http://www.canalworld.net/forums/index.php?showtopic=27198

[Flyboy]

Are you sure about this? I've been using Carplan or Tescos deionised water which says "for batteries". What's the difference exactly?

 

Have I been using the wrong stuff all this time?

Deionised, distilled or even rainwater collected in a plastic container are all ok. I know of people that used the defrost water from a fridge with no problems.

[soldthehouse]

These all sound like good reasons for a mooring with shore power and a nice float charge all winter (with an occasional bulk & absorption charge of course).

I think the point is that its the temparature not the state of charge thats so important, if the battery is very very cold the power is reduced so charging a very very cold battery wont achieve anything on its own...

[blackrose]

I think the point is that its the temparature not the state of charge thats so important, if the battery is very very cold the power is reduced so charging a very very cold battery wont achieve anything on its own...

 

I was making a slightly different but related point, that if the batteries are kept on a float charge their temperature will not get very very cold in the first place.

 

This is just my intuitive feeling as my knowledge of batteries and charging is limited, so I'm ready to be corrected.

 

Deionised, distilled or even rainwater collected in a plastic container are all ok. I know of people that used the defrost water from a fridge with no problems.

 

So twocvbloke, why the caution against using deionised water?

Edited January 27, 2010 by blackrose

[barge sara]

I was making a slightly different but related point, that if the batteries are kept on a float charge their temperature will not get very very cold in the first place.

This is just my intuitive feeling as my knowledge of batteries and charging is limited, so I'm ready to be corrected.

 

Our traction batteries are on permanent float / maintenance charge when we're not aboard. Battery temperature has yet to drop below 4 degrees C. I guess if the batteries are already full then the minimal float current has to go somewhere and heat is the obvious place.

 

I too would be very keen to know why not ionised water, as I've been happily tipping it into our £3.5K worth of batteries for the last couple of years! I'd always understood that distilled and ionised were two different ways of arriving at the same product.

[twocvbloke]

So twocvbloke, why the caution against using deionised water?

 

The difference between Distilled and Deionised water is that Deionised still contained minerals that can cause damage to the battery when discharging, leaving unwanted deposits on the plates which hampers performance. The only reason why Deionised is sold "for batteries" is because it's a cheap solution for those not in the know...

 

Distilled water is basically the condensed steam from boiled water, it contains practically no unwanted minerals, and is so easy to make by yourself, infact, most boaters do it every day when they boil a kettle and it condenses on the hull or windows...

 

If you can capture* the condensed water, you've got a pretty much free battery top-up solution in your hands, no need to buy something that'll most likely cake your plates up...

 

 

*One way is to put a large pan lid on a small pan at an angle, so one edge hangs over the outer rim of the pan and the other side into the pan, and aim a kettle of boiling water at the open edge, the water then condenses on the lid and falls into the pan, and there you have free Distilled water...

 

If you want to be fancy, and more efficient, look up a glass distiller tube on ebay, preferably the one with the spiral core, that has cold water running over the coil which has the steam passing through which in turn condenses and makes distilled water...

[soldthehouse]

I was making a slightly different but related point, that if the batteries are kept on a float charge their temperature will not get very very cold in the first place.

 

This is just my intuitive feeling as my knowledge of batteries and charging is limited, so I'm ready to be corrected.

 

 

 

So twocvbloke, why the caution against using deionised water?

I see where you are coming from but like you i,m no expert on these matters and dont know whether any effort might be better directed at heating the batteries or insulating them, but then the ventilation thing raises its head, winter in the med seems the sensible answer...

 

The difference between Distilled and Deionised water is that Deionised still contained minerals that can cause damage to the battery when discharging, leaving unwanted deposits on the plates which hampers performance. The only reason why Deionised is sold "for batteries" is because it's a cheap solution for those not in the know...

 

Distilled water is basically the condensed steam from boiled water, it contains practically no unwanted minerals, and is so easy to make by yourself, infact, most boaters do it every day when they boil a kettle and it condenses on the hull or windows...

 

If you can capture* the condensed water, you've got a pretty much free battery top-up solution in your hands, no need to buy something that'll most likely cake your plates up...

 

 

*One way is to put a large pan lid on a small pan at an angle, so one edge hangs over the outer rim of the pan and the other side into the pan, and aim a kettle of boiling water at the open edge, the water then condenses on the lid and falls into the pan, and there you have free Distilled water...

 

If you want to be fancy, and more efficient, look up a glass distiller tube on ebay, preferably the one with the spiral core, that has cold water running over the coil which has the steam passing through which in turn condenses and makes distilled water...

Does melted ice achieve the same result.

[twocvbloke]

Does melted ice achieve the same result.

 

Erm, no, ice is generally created with atmospheric vapour, which as always, can contain contaminants (think Dinofuel exhaust, soot, dust & dirt etc.) which are bad for battery plates, but if you distilled it, then yes, it would be usable...

 

Infact, pretty much any water (be it drinking, snow, canal, not bodily fluids though!!!) if distilled is fine...

[nb Innisfree]

If a batteru is fully charged at, say, 20c then left to cool to, say, 2c will it then take more charge?

Edited January 27, 2010 by nb Innisfree

[WotEver]

*One way is to put a large pan lid on a small pan at an angle, so one edge hangs over the outer rim of the pan and the other side into the pan, and aim a kettle of boiling water at the open edge, the water then condenses on the lid and falls into the pan, and there you have free Distilled water...

Only if the pan and lid are made of glass or, er, plastic...

 

Tony

 

Another thing, the misconception that batteries perform worse in winter...

 

It's not a misconception. Batteries (all batteries, not just lead/acid batteries) will indeed perform worse in winter. That doesn't mean that there's anything wrong with the battery, just that the chemical reaction is slowed by the cooler temperature.

 

Tony

[barge sara]

The difference between Distilled and Deionised water is that Deionised still contained minerals that can cause damage to the battery ...

 

With all respect to CV Bloke I'm still sceptical.

I've just spent some time Googling the subject and found:

- All the battery topup water for sale is specifically described as deionised, not distilled (Halfords are just one example).

- None of the 'battery related' sites contain any warning that distilled not deionised should be used for batteries.

- Those sites describing the deionisation process seem to be saying the end product is 'pure' water.

 

Now I don't subscribe to the "It's on the 'net so it must be true" persuasion, but I would really like to see an authoriatative statement one way or the other.

I have a very expensive battery bank to maintain and squeeze the longest possible life from.......