Issues with lithiums in very cold weather?

[Guest]

1 minute ago, Tony1 said:

 

If that was intended even partly for my attention, I can only say that to expect me to have any regard for one of your posts is the daftest idea I've heard in a very long time. 

 

 

Well come on.

 

 

Really?

 

I see youve had the balls to admit you were wrong though.

 

Fair play, not many would.

[Tony1]

2 minutes ago, M_JG said:

 

Well come on.

 

 

Really?

 

Erm, yes.

 

Really.

 

 

Edited July 24, 2023 by Tony1

[Guest]

Just now, Tony1 said:

 

Erm, yes.

 

Really.

 

 

 

Ah right.

 

Lol.

[Naughty Cal]

9 hours ago, Tony1 said:

 

In normal temps, yes, it is.

But in sub zero temps the BMSs in lithiums will sometimes disconnect the battery from charging (and with some BMSs, disconnect from discharging too)

So my guess is that they resolved it by running the engine for 30 mins or so just to warm up the engine bay a bit, at which point the lithiums will have warmed up above zero, and will have reconnected themselves, and will now accept a charge.

Or something akin to that.

 

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. 

Edited July 25, 2023 by Naughty Cal

[rusty69]

9 hours ago, MtB said:

 

My LiFePO4 battery has a heating element built in, and should you try to charge it at minus <whatever> degrees C, it will divert the charge current to the heater elements until the cells have warmed up to (I think) 5 degrees C. 

 

Neat, eh? 

 

 

Yes. 

 

Or perhaps Heat eh? 

[magnetman]

10 hours ago, nicknorman said:

 

What an astonishing piece of shit.

 

The recall notice I mean, not the product. Here is some of the text:

 

The terminals were not sufficiently insulated or recessed to prevent accidental short circuiting, and the earthing arrangements were insufficient, presenting a risk of overheating and fire. The blue product does not contain a battery management system nor have a fuse on the output. There was also no discharge cut-off voltage, making it possible for the battery to overcharge and overheat.

 

Terminals not insulated or recessed … just like any other battery

 

Earthing arrangements … since when did a 12v battery have “earthing arrangements”

 

No fuse on the output ... Just like every other 12v lead acid battery

 

No discharge cut-off voltage -> possible to overcharge? Do they understand the difference between charging and discharging? Obviously not.

 

Someone needs a good slapping. And we are paying their salary.

 

Some properly designed batteries do have recessed terminals but it is quite unusual. 

 

My LTO modules can't be shorted with a flat object which is handy given they have a 10C designed discharge rating. 

 

These. 6S2P LTO. I charge to 15v which is about 90% so its around 36Ah per module. 

It is reasonable for them to point this out. 

 

 

Designed for 400A discharge at 16.8v.  The connection to the cells consists of aluminium bar which is effectively an overload fuse. 

 

These beasts can start big diesel engines easily. 

 

No BMS but LTO is supposed to be very tolerant. Time will tell.

 

Very Unusual to find these and they had all gone before I realised I wanted a lot more. 

Edited July 25, 2023 by magnetman

[booke23]

5 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. 

 

Remember in a boat engine bay, you've got an engine at 80C, which warms the area up to significantly more than room temperature. Having said that, in a very cold snap it still took 90 minutes of engine running before my battery got up to 5 degrees. 60 minutes is more typical.  

[Mike Todd]

20 hours ago, Tony1 said:

 

Tbh Rusty if my lithium install does fail, they will be temporarily disappeared and replaced with cheap and nasty lead acids in time for the follow up inspection.  

 

I think all the B2Bs and MPPTs can stay in place, and the 'domestic' bank of lead acids could be charged via B2Bs, in the same way as my lithiums are at the moment- at least that shouldn't be a failure. 

 

And then, as soon the BSS is issued, the lead acids will be found a new home with a deserving nearby boater. 

You just hope it doesnt come to that really, but I can see all sorts of shenanigans going on if/when the new regs come into force. 

 

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.

[magnetman]

I didn't mention hiding the lithium batteries on a well known internet forum so hopefully it will be okay. 

 

Unsurance companies will have minions crawling these sites for tid bits.

 

Or bots. There is probably an automatic bot which pics up 'lithium battery' and feeds all the gen to Lloyds of London. 

 

 

[rusty69]

But thankfully you will still be able to charge your cheap Chinese e-battery thing without any regulations preventing you. 

2 minutes ago, magnetman said:

I didn't mention hiding the lithium batteries on a well known internet forum so hopefully it will be okay. 

 

Unsurance companies will have minions crawling these sites for tid bits.

 

Or bots. There is probably an automatic bot which pics up 'lithium battery' and feeds all the gen to Lloyds of London. 

 

 

Me neither. I would never condone such behaviour. 

I don't even own a blanket 

[magnetman]

I have an electric blanket but it is NOT powered by a lithium battery. 

[rusty69]

Can you prove that to the satisfaction of the BS examiner? 

[TheBiscuits]

Just now, rusty69 said:

Can you prove that to the satisfaction of the BS examiner? 

 

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

[magnetman]

I will hide it under the mattress with all the old bank notes. 

[rusty69]

Just now, TheBiscuits said:

 

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

Hmmm. That's a good idea.

[magnetman]

Just now, TheBiscuits said:

 

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

Many yars ago I asked the scrap battery man if I could take the plastic boxes off and just sell him the insides but he was not keen. I think they probably reuse them. 

[rusty69]

5 minutes ago, TheBiscuits said:

 

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

Anyway. If you misrepresent a battery as something it isn't, and subsequently get caught, your likely to get  LiFe.

 

Ok,im going. 

[magnetman]

11 minutes ago, rusty69 said:

, your likely to get  LiFe.

 

Ok,im going. 

Thats not as bad as being cast away NMC based hulk ships. 

[Ronaldo47]

In the 1970's I was working with an electronics engineer who had spent his time in the army in the Royal Signals Corp.  One day when we were discussing lead-acid batteries, he said that one of his regular duties had been to do a discharge/charge cycle on them every six months to keep them in good condition.. He also said that, in really cold weather when the batteries' cranking voltage was a bit low, drivers would warm them.up before trying to start their engines by briefly shorting the terminals with a large spanner (held in a gloved hand!). The heavy short circuit current would warm the batteries enough to raise the cranking voltage and thus ensure reliable first-time starting,  avoiding flooding the carburettor.  Don't try this with lithiums! 

Edited July 25, 2023 by Ronaldo47
typos

[Alan de Enfield]

27 minutes ago, rusty69 said:

Hmmm. That's a good idea.

 

 

Youse goin to do this guy out of a job !

 

 

[rusty69]

2 minutes ago, Alan de Enfield said:

 

 

Youse goin to do this guy out of a job !

 

 

Unlikely. I haven't got any pink marigolds. 

[Iain_S]

18 hours ago, ditchcrawler said:

If you read what I put you will see why I put it there. People with an interest in lithium will no doubt be reading this and its possible they have bought them. You are not the only person with lithium batteries on a boat, most people would probably buy a drop in battery rather than put a system together like you have.

If it doesn't have a BMS, it's hardly a drop in battery. If it was being sold as such, then the recall is understandable, although the notice does over egg the pudding with additional irrelevant garbage.

[magnetman]

I thought there were some quite good points made. Not sure how a recall will work in this instance but presumably it will be to protect the supplier.

 

They may have been erroneously marketing NMC chemistry as LFP and having realised their mistake put in a recall.

 

Would need looking into more closely before poo poo ing I think. 

[rusty69]

The recall appears to require the purchaser to dispose of the batteries themselves. Presumably this requires them to transport these highly dangerous batteries at great personal risk. 

 

I hope they are offered not only a full refund, but a certain amount of danger money as compensation. 

[magnetman]

18 minutes ago, rusty69 said:

The recall appears to require the purchaser to dispose of the batteries themselves. Presumably this requires them to transport these highly dangerous batteries at great personal risk. 

 

I hope they are offered not only a full refund, but a certain amount of danger money as compensation. 

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