Issues with lithiums in very cold weather?

[rusty69]

4 minutes ago, magnetman said:

Maybe the idea is you just throw them over the side and avoid the personal rusk issue. 

That's easy for you to say, surrounded by water, as you are, but what about the van people. Could get messy avoiding piles of dodgy batteries on the motorways. 

 

And what about the poor fish. Not to mention the seals. 

Batteries are for LiFe, not just for Christmas. 

Edited July 25, 2023 by rusty69

[Tony1]

2 hours ago, Mike Todd said:

That of course would invalidate your BSS, as I understand it you have to re-check after any  significant modification, not to mention possible fraud! You might only find out about when your insurance company declines a large claim.

 

Naw, I was just kidding around Mike. 

Although, I do wonder how many people have made significant modifications to their boats, and have not informed their insurance company or the BSS people, and could even now be cruising around with their insurance cover potentially at risk. 

 

I should probably contact the BSS and make sure those new wind chimes above the bow door are compliant. 

 

 

11 hours ago, Naughty Cal said:

When our battery did a cold weather disconnect it took it a lot longer to reallow charging than 30 minutes,  despite the battery being in the heated hab area of the van.

 

It was a fair few hours with the van heating on before the battery reached 5 degrees internally (despite the van heating up to 21 degrees fairly quickly) and charging was allowed again. 

 

I'm hoping to avoid them ever going below zero, by ducting air into the battery box from the cabin using a very small fan. 

If I let magnetman design it, he would have three gerbils running on a wheel to operate a pump, getting electric shocks every 30 minutes to keep them motivated. 

 

[rusty69]

5 minutes ago, Tony1 said:

 

Naw, I was just kidding around Mike. 

Although, I do wonder how many people have made significant modifications to their boats, and have not informed their insurance company or the BSS people, and could even now be cruising around with their insurance cover potentially at risk. 

 

I should probably contact the BSS and make sure those new wind chimes above the bow door are compliant. 

 

 

 

I'm hoping to avoid them ever going below zero, by ducting air into the battery box from the cabin using a very small fan. 

If I let magnetman design it, he would have three gerbils running on a wheel to operate a pump, getting electric shocks every 30 minutes to keep them motivated. 

 

Just redirect the powerful blast from your eco fan into some ducting.

 

No gerbils required. 

[Tony1]

Just now, rusty69 said:

Just redirect the powerful blast from your eco fan into some ducting.

 

No gerbils required. 

 

I'm not sure why you're suddenly all gerbilist

 

[rusty69]

5 minutes ago, Tony1 said:

 

I'm not sure why you're suddenly all gerbilist

 

Because to install a complete new set of gerbils, without an adequate GMS requires permission from the BS scheme. 

 

Eta, if you were to use a squirrel instead, no additional safety features are required. The BS scheme already accommodates squirrels. 

Edited July 25, 2023 by rusty69

[Tony1]

20 minutes ago, rusty69 said:

Because to install a complete new set of gerbils, without an adequate GMS requires permission from the BS scheme. 

 

Eta, if you were to use a squirrel instead, no additional safety features are required. The BS scheme already accommodates squirrels. 

 

I do like that squirrels are already approved, but I just have a thing for gerbils.

Not in any sinister way though. Not that kind of of a thing.

 

But then I would say that.

 

 

 

[Naughty Cal]

53 minutes ago, Tony1 said:

 

Naw, I was just kidding around Mike. 

Although, I do wonder how many people have made significant modifications to their boats, and have not informed their insurance company or the BSS people, and could even now be cruising around with their insurance cover potentially at risk. 

 

I should probably contact the BSS and make sure those new wind chimes above the bow door are compliant. 

 

 

 

I'm hoping to avoid them ever going below zero, by ducting air into the battery box from the cabin using a very small fan. 

If I let magnetman design it, he would have three gerbils running on a wheel to operate a pump, getting electric shocks every 30 minutes to keep them motivated. 

 

We had hoped that ours wouldn't drop below zero degrees given its inside. Certainly isn't the case though, although it doesn't seem to happen all that often.

[magnetman]

On a boat it happens a lot less often than in a vehicle because of the water. 

[Tony1]

29 minutes ago, Naughty Cal said:

We had hoped that ours wouldn't drop below zero degrees given its inside. Certainly isn't the case though, although it doesn't seem to happen all that often.

 

I keep the stove ticking over all night in winter, whereas in a van you'll be using maybe a diesel heater, that goes off at bedtime? 

So my hope is that there will a constant supply of warm air in the cabin.

The question is whether air at say 15 degrees will be enough keep a battery box above zero. 

It's got to be worth a try.

If it fails the BSS then its back to a gerbil powered air pump. Or I could set the gerbils upon the inspector, and end his miserable existence. 

 

 

 

[magnetman]

What about the blanket idea? 

 

 

CheeryTea shops often have dog bed materials in the form of not all that clean blankets and towels. Cheep. Just pretend you have a dog. Or a budgie. 

 

 

[Naughty Cal]

43 minutes ago, Tony1 said:

 

I keep the stove ticking over all night in winter, whereas in a van you'll be using maybe a diesel heater, that goes off at bedtime? 

So my hope is that there will a constant supply of warm air in the cabin.

The question is whether air at say 15 degrees will be enough keep a battery box above zero. 

It's got to be worth a try.

If it fails the BSS then its back to a gerbil powered air pump. Or I could set the gerbils upon the inspector, and end his miserable existence. 

 

 

 

Our van is gas heating which we leave on overnight in the winter when we are out at about 16 degrees. 

 

It's only when the van is sat unheated on the drive that the battery drops cold enough to trigger the BMS.

 

We find that our battery seems to stay quite cool compared to the surrounding air temperature.  

[rusty69]

One of the issues I had with out lithium batteries last winter, which are situated in the engine room of a traditional style narrowboat was condensation. 

 

The condensation formed on the copper bus bars and subsequently deposited itself on top of the cells.

 

Because the cells were not able to drain the condensation from the top, there was quite a build up. 

 

The other thing I noticed is that that aluminium terminals suffered quite badly. 

 

I have since insulated the bus bars, so hopefully next winter they will behave better. 

Edited July 25, 2023 by rusty69

[Tony1]

46 minutes ago, magnetman said:

What about the blanket idea? 

 

 

CheeryTea shops often have dog bed materials in the form of not all that clean blankets and towels. Cheep. Just pretend you have a dog. Or a budgie. 

 

 

 

Have you any idea of the consequences of falsely claiming to have a budgie on a narrowboat? 

You really haven't thought this through. 

 

 

[TheBiscuits]

2 minutes ago, Tony1 said:

 

Have you any idea of the consequences of falsely claiming to have a budgie on a narrowboat? 

You really haven't thought this through. 

 

 

 

It's OK, nobody knows it's there.  He smuggled it!

[rusty69]

Just now, TheBiscuits said:

 

It's OK, nobody knows it's there.  He smuggled it!

In his raffia hat 

[Tony1]

13 minutes ago, Naughty Cal said:

Our van is gas heating which we leave on overnight in the winter when we are out at about 16 degrees. 

 

It's only when the van is sat unheated on the drive that the battery drops cold enough to trigger the BMS.

 

We find that our battery seems to stay quite cool compared to the surrounding air temperature.  

 

I should be realistic about what a warm air duct system can achieve, especially when the batteries are out in the engine bay with an air temp of minus 9 on some very occasional mornings. 

I think I'll give the air duct a go, as its cheap and easy ish to install, but it sounds like other measures might also be needed on the really cold mornings. 

The one good thing is that although you cant charge them below zero, you can still draw current from the lithiums at minus 10, so at least I can still have power (although I might break out the old gas kettle again on some mornings). 

 

 

 

 

[TheBiscuits]

Just now, rusty69 said:

In his raffia hat 

 

Not usually

 

[Tony1]

1 minute ago, TheBiscuits said:

 

It's OK, nobody knows it's there.  He smuggled it!

 

And this from the man who suggested using lead acid battery cases to house lithiums, and putting labels on them saying "Definitely Not Lithium". 

You are on very thin legal ice sir.

 

(Do they actually sell those though? A friend was asking) 

 

[MtB]

6 hours ago, TheBiscuits said:

 

I can see a market for empty plastic battery cases with Lead Acid stickers on them ....

 

 

I can see a ready market for drop-in LiFePO4 batts disguised as LAs. 

 

Plausible deniability for the BSS bod and for the boater!

 

One helluva business opportunity actually...

 

 

 

[TheBiscuits]

Just now, MtB said:

I can see a ready market for drop-in LiFePO4 batts disguised as LAs. 

 

Plausible deniability for the BSS bod and for the boater!

 

One helluva business opportunity actually...

 

It's the exact opposite of the cunningly named Lion brand lead acid batteries ...

Actually, maybe just the stickers off those would do!

[nicknorman]

1 hour ago, Tony1 said:

 

I should be realistic about what a warm air duct system can achieve, especially when the batteries are out in the engine bay with an air temp of minus 9 on some very occasional mornings. 

I think I'll give the air duct a go, as its cheap and easy ish to install, but it sounds like other measures might also be needed on the really cold mornings. 

The one good thing is that although you cant charge them below zero, you can still draw current from the lithiums at minus 10, so at least I can still have power (although I might break out the old gas kettle again on some mornings). 

 

The batteries will only get cold if they lose heat. Heat loss can be substantially reduced by insulation. A well insulated battery box will still lose heat slowly, but this heat loss can be made up by wafting warm cabin air over them.

 

In other words, insulate your battery box well.

[magnetman]

It is interesting that such people as Fogstar put heating systems in the batteries. Presumably this is for batteries which are left unused but one wonders what the situation is if they are under constant discharge. Would this discharge generate a bit of heat and stop them actually getting too cold in the first place. 

 

There is another possibility which is that having heating systems in the battery is a marketing strategy. 

 

 

[nicknorman]

Just now, magnetman said:

It is interesting that such people as Fogstar put heating systems in the batteries. Presumably this is for batteries which are left unused but one wonders what the situation is if they are under constant discharge. Would this discharge generate a bit of heat and stop them actually getting too cold in the first place. 

 

There is another possibility which is that having heating systems in the battery is a marketing strategy. 

 

if the discharge is significant then this generates some heat. Ditto a significant recharge. But a typical usage pattern would include long periods of very low discharge (overnight) which will result in cold batteries (on a cold night). The idea is that you start to recharge them in the morning but the BMS diverts the charging current into the heating mats, until the battery is warm enough.

[magnetman]

I can see how it works but it must also be quite a good strategy to be able to say "ours have heating pads theirs don't" regardless of whether it actually makes any difference in real life situations.

 

 

[MtB]

22 minutes ago, magnetman said:

Would this discharge generate a bit of heat and stop them actually getting too cold in the first place. 

 

I doubt it. The internal resistance of LiFePO4 cells is so low that I'd have thought hardy any energy will be dissipated inside the battery during discharge. 

 

Some basic calculations would reveal the amount of heating effect. Does anyone have any values to hand for LiFePO4 cell internal resistances?