Charging LiFePo4

[GunterBeckman]

Hi
why we must not charge LiFePo4 below 32°F/0°C?

[Burgerman]

Because it can damage them. Wrong chemistry happens when adding power below certain temperatures. Having said this I have charged many lithiums below this point in hobby use, both lifepo4 and lipo, and never had a problem as the act of charging at least at a sensible rate adds a few degrees anyway.

But if its genuinely colder than 0c dont charge. It will result in lithium plating instead of charging. Permanant damage. You can discharge down to -20C or so safely. If you must charge when its so cold then you can do it without damage at or below the 50h rate. That is apparently slow enough that plating doesent occur. Not tried by me... (wiki).

[thamesmud]

Some of the motorhome nuts who use lithium iron phosphate batteries put heater mats under the batteries to warm them up prior to charging. It's a big problem if you have solar panels and the van is unattended.

[Burgerman]

Well its an easy fix. Add a thermostat in series with a charge wire with relay, and set to 1C.

[GunterBeckman]

Because it can damage them. Wrong chemistry happens when adding power below certain temperatures. Having said this I have charged many lithiums below this point in hobby use, both lifepo4 and lipo, and never had a problem as the act of charging at least at a sensible rate adds a few degrees anyway.

But if its genuinely colder than 0c dont charge. It will result in lithium plating instead of charging. Permanant damage. You can discharge down to -20C or so safely. If you must charge when its so cold then you can do it without damage at or below the 50h rate. That is apparently slow enough that plating doesent occur. Not tried by me... (wiki).

thanks

[GunterBeckman]

so LiFePo4 is not yet a reliable solution for cold places/winter
hope in future we'll have the right technoligy

[Burgerman]

You can get heaters, etc and warm prior to charging. Tesla for eg circulate heated coolant to warm them as needed. An electric blanket or something is all tats needed. And only then if its below zero. So not really much of a problem. Just a little common sense or a thermostat.

Plus if you fitted a big enough pack, as you really should be doing, you would have 5 times the range. And so no need to charge for days at a time. Just do it fast when its warmer during the day or something.

[GunterBeckman]

when it's -74°F it's a huge blanket my LiFePo4 will need

[Burgerman]

Whats that in proper units?
-58.88889C
You would be dead...
My freezer is -16C

All batteries will fail to work at that temperature. But that cant be correct?

[GunterBeckman]

thanks to God you are wrong!
this temperature is a normal one during winter in Ak or NWT
and every day we can start our trucks with lead batteries

[Burgerman]

But even lead doesent like being charged at those temps.

At -20c which is nowhere near your claimed figure, the lead brick has just 20% of its normal rated capacity and its charge voltage is way higher than your car produces. And current making caability needed to start a vehicle drops accordingly.
At -40 it barely works at all. And shouldnt be charged either even if it were to accept any charge, and the battery capacity at his point is barely above zero Ah anyway.

So it either doesent get to the low temperature you describe very often or your cars wouldnt start. Or charge. And a quick look online shows average winter temp in norway as -6 to 7C. With isolaed spots that can hit -35 to -40 intermittently.

Read: https://www.victronenergy.com/blog/2019 ... d-weather/

I see pictures of tesla charging stations in norway in high cold mountains. Do these not work? Well the odd one doesent work everywhere, I mean because of cold.

Remember that you are discharging at 3 or 4x Cap (4C) during a winter start because of cold oil etc. CCA rate.

This only shows how bad lead is at -20C and would be off the chart at -40! Even at 1C discharge!
Lead brick V temperature.

[GunterBeckman]

i don't care if my lead batteries like or not real winters from here
what i know is everyday after starting my trucks batteries are charging
it's the only important point for us here
what seems to be impossible -IN THE SAME CONDITIONS- with LiFePo4

your drawings are nothing for us here
only results AND reliability are important here
our lifes are 100% depending of reliability into the Wild

[shirley_hkg]

Why would you want something other than SLA batteries ?

[Burgerman]

I think I might move.

On the other hand I found this.
https://thenorwayguide.com/find-ev-charging-stations/

Seems EVs are very common in norway. Even the northern parts. So a warmng system/blanket as suggested previously seems to work just fine. As most EVs use them. Ant its probably not quite as cold daily as the extremes suggested.

[GunterBeckman]

Why would you want something other than SLA batteries ?

what are SLA batteries?

[GunterBeckman]

I think I might move.

On the other hand I found this.
https://thenorwayguide.com/find-ev-charging-stations/

Seems EVs are very common in norway. Even the northern parts. So a warmng system/blanket as suggested previously seems to work just fine. As most EVs use them. Ant its probably not quite as cold daily as the extremes suggested.

when you snow biking for 10 or 15 days you cannot bring the all stuff from your shed even a power blanket ...

but no worry we'll continue using lead batteries until a new technoligie over LiFePo4 will arrive, if ...

lead battery is working good enough for our purpose I was just thinking about LiFePo4 but not good for normal winters here

thanks trying helping

[Burgerman]

what are SLA batteries?

Sealed Lead Acid

[GunterBeckman]

Why would you want something other than SLA batteries ?

main reason is wheight

[GunterBeckman]

what are SLA batteries?

Sealed Lead Acid

thank you

[Burgerman]

All batteries are a chemical reaction.
All chemical reactions go slower and slower as temperature falls. And the opposite is also true...
Lead is equally bad at low temperature discharge like car starting. But both can be used.
This wont get better anytime soon.

And just having read about your country and spoken to a freind that works for BAE Systems that just came back from norway (work) it appears that you have a simply huge EV car network and things like tesla superchargers are everywhere! Driven by taxation. And rebates. And a crazy lefty net zero goverment...
These appear to work great even in the north of your country.

So it must be possible to insulate and or wrap your battery in the equivelent of an electric blanket that runs from the charger or the pack that is thermostatic. It works for others.
These sort of pads below for e.g. take little power and are what many people are using.
https://uk.rs-online.com/web/p/heater-pads/0245528
Or https://www.amazon.com/Upgrade-Version- ... 281&sr=8-1
You just wire it through a thermostat so your solar heats the battery, and when it reaches above 0C (say 5) it charges the battery instead.
Takes no space, a couple mm thick. You can sit the pack on these, or fit one between each cell.

Another question.
Since you can get at least 5x the capacity, for around 2/3rds the mass with LiFePO4 as we already do in chairs now, which means far less charging is actually needed. Wouldnt it still make sense to use 5x the Ah of LiFePO4 anyway? That done correctly takes up the same space/volume, and a fair bit less weight. Just charge once a week on the less cold days instead of every day or whenever it is safe.

[GunterBeckman]

buddy, first of all, you don't understand at all the use we have with snow bike in Ak, or NWT

second, about that ''it appears that you have a simply huge EV car network and things like tesla superchargers are everywhere!'' if you can show me 1, not 4 or 3 even 2, only 1 a Tesla supercharger in NWT or Ak, you're a king

third, as i said before, when you go hunting for some days by snow bike 1Lbs more or less is very important even essentiel

fourth, about that ''Another question.
Since you can get at least 5x the capacity, for around 2/3rds the mass with LiFePO4 as we already do in chairs now, which means far less charging is actually needed. Wouldnt it still make sense to use 5x the Ah of LiFePO4 anyway? That done correctly takes up the same space/volume, and a fair bit less weight. Just charge once a week on the less cold days instead of every day or whenever it is safe.''
you don't read what we are doing with our snow bike here
they are not hobby wheelchair but the way we have in winter to stay alive
we don't have a wall plug even once a week for 15 days or sometime more and the less cold days are ... 3 months a year
we are not here to play as people are playing video game
when the game is over here it's our life wich will be over too ...


and to finish, since decades we are using SLA during our winters WITHOUT any kind of problem
we don't need problem when we are in the wild with -74°F
we don't need power blanket for us we will not waste place/load for a battery blanket

LiFePo4 are working well -i can say that because of almost 60 i installed in my RV a few months ago- however LiFePo4 are not usable in winter for those who are in the wild during several days
that's all

thanks for your help and enjoy

[Burgerman]

Tesla high speed superchargers?
Theres 120 sites of those in a small country. https://www.tesla.com/findus/list/superchargers/Norway
At each location theres approx 16 to 20 of these superchargers 24/7.
And also theres lots of non tesla and slower tesla chargers too.

But OK if you say not suitable for your purpose then you dont have to use lithium!

[GunterBeckman]

why are you always speeking about Norway while i'm in North America?
really i don't understand your goal

[GunterBeckman]

And just having read about your country and spoken to a freind that works for BAE Systems that just came back from norway (work) it appears that you have a simply huge EV car network and things like tesla superchargers are everywhere! Driven by taxation. And rebates. And a crazy lefty net zero goverment...
These appear to work great even in the north of your country.

again and again i'm NOT in Norway and don't care about this country

for next Christmas remember me to buy you a world map as it seems you didn't move a lot from your small UK

[GunterBeckman]

In Chicago, due to the cold snap, Tesla vehicles remain immobilized near charging stations, unable to recharge. An incredible situation to discover on video.

The city of Chicago is currently facing an extreme cold snap with temperatures regularly plunging below 22°F. This natural phenomenon causes big problems for Tesla vehicle owners.
Due to these difficult weather conditions, recharging the batteries was impossible. Electric vehicles have remained frozen in Supercharger stations, which have become ice graveyards.

THE INTENSE COLD OF CHICAGO MAKES TESLA UNUSABLE
Generally, intense cold never goes well with car mechanics, even thermal ones, particularly at the electronic level. It is therefore no surprise that electric vehicles subjected to these freezing temperatures saw a notable drop in their battery performance.

Tesla owners in Chicago reported that, even when plugged in, they were no longer able to charge properly, leading to low range or total immobilization.
Among these unfortunate owners, a man with a Tesla Model 3 expressed his frustration with the problem with his vehicle. “I didn’t pay $60,000 to see the battery melt like that,” he said.

[Burgerman]

Fake news mostly. And healthy batteries dont melt. They are controlled properly by the car and heated as required.
There is no temperature point that charging stops working.
Blown out of all proportion for clickbait by those in the US that hate EVs and net zero. I hate it too, but I like facts not typical nonsense made up for clickbait.

Unless the charge port is frozen over which is the only thing that prevents charging happening. It does however waste some time heating the pack to begin with so ignorant owners think its not charging. And range is reduced even without the wasted power for heating the car. Which caught out many ignorant owners driving against strong gale force headwinds recently (eats power) with the heater on in some cheaper low range (smaller battery) teslas when their usual daily trip ran them out of power... This is more a case of ignorance giving the exact result you would expect. That happens with everything. Knowledge is power.

Heres what actually happens to your tesla:
After a -20C cold-soak you have zero braking regen and power output is limited to 80 kW until the battery warms through use. Range is approx 80% of normal. Maybe less with car heater on.
The recharge will start at ~6kW and stay there for ~10 minutes with all energy from the charging station going to towards heating. After that it then ramps up to 14 kW within 15-20 minutes of plugging in. And on.

In some teslas you can also choose to preheat the battery before charging using its own power while driving. To save time. (Or to increase performance). This also reduces range of course. But the very act of driving also warms the battery too, so charging a just driven car seldom needs extra heating anyway..

[daveonwheels]

https://en.wikipedia.org/wiki/Northwest_Territories
or as i call it, not norway!

[Burgerman]

I would suggest you are like that frog. The one that you can cook alive. If you gradually increase the temperature and do it slow enough the frog never actually decides to jump out of the pan. It just never notices the temperature increase is happening and it gets used to the temperature. And that jump moment never happens. Till its all too late.

But the other way around. I would suggest that anyone living there is the exact same thing in reverse. It makes no sense for a human to put up with that sort of suffering and cold when there are much better climates to live in elsewhere across a large planet. They may try and rationalise this after the event to justify "why" they live there. But its all basically nonsense. Living in that type of climate makes no rational sense.

[GunterBeckman]

I would suggest you are like that frog. The one that you can cook alive. If you gradually increase the temperature and do it slow enough the frog never actually decides to jump out of the pan. It just never notices the temperature increase is happening and it gets used to the temperature. And that jump moment never happens. Till its all too late.

But the other way around. I would suggest that anyone living there is the exact same thing in reverse. It makes no sense for a human to put up with that sort of suffering and cold when there are much better climates to live in elsewhere across a large planet. They may try and rationalise this after the event to justify "why" they live there. But its all basically nonsense. Living in that type of climate makes no rational sense.

no rational sense ... Lol
my friend, when your job is here or anywhere, when you've a family to feed, rational sense is NOT in your vocabulary
the only word you know in this situation is UNDER OBLIGATION

i can guess you're not in this situation ...

[Burgerman]

Yes I am in britain. Its gradually turned lefty, socialist and is being taken over by african and muslims. Weather has no extremes but there are other problems. Like the bankrupting net zero nonsense.

So I should move somewhere better. But its happening gradually and so I never jumped...