Best practice for freezing temperatures and lifepo4 batteries

[SolarQueen]

Did you see Will's video with Battleborn's CEO talking about cold temp charging?

 

[offgriddle]

SO FAR, lifepo technology chemistry is limited to discharging of the batteries down to 32F, (0C). If the batteries experience -4F, (-20C), they are ruined, toast, finito games over, so I'm told.

Essentially what this means is if you cannot keep your lifepo's always above 32F/0C forever and ever, no matter where you are and no matter where they are, I suggest going with AGM's while you await a superior battery technology to come along.

 

[offgriddle]

Did you see Will's video with Battleborn's CEO talking about cold temp charging?

I think that the shorepower charger has a circuit that warms the lithium ion, heater equipped, battery up first before engaging the charging circuitry, right?

 

[nosys70]

it is really easy to keep something over 0C, even if left unattented for weeks.
you first build an isolated box, you put a small heater inside, and just a minimal current load for charging and discharging should be enough to maintain a decent temperature.
even a black paint metal sheet become warm in winter, provided you get some sun.
a small solar vacuum tube should fit the need.

 

[offgriddle]

it is really easy to keep something over 0C, even if left unattented for weeks.
you first build an isolated box, you put a small heater inside, and just a minimal current load for charging and discharging should be enough to maintain a decent temperature.
even a black paint metal sheet become warm in winter, provided you get some sun.
a small solar vacuum tube should fit the need.

The only way that I have been able to keep my lithium ion phosphate batteries from freezing of grid, without relying on the limited charge stored in the batteries to power a heating device, or without relying on any other heat source that requires energy, is to keep them in a root cellar that is deep enough below frost to stay above freezing. So far so good.

 

[kernel]

Did you see Will's video with Battleborn's CEO talking about cold temp charging?

Yes, and in it he does speak to the fact that as long as the charge rate is properly ramped up there would be no structural damage or plating of the electrodes and so charge current can be carefully used even when in the "never charge" temp range. I think he was specifying some pretty low temps.

And batteries with internal heating devices..... i think he said thatcontrollers are needed to help make low temp charging practical amd safe for the batteries.

 

[ekarlson]

I just read the article on the new Renogy DC-DC Charger w/ MPPT and I think this would solve my problem, it has built in lithium low temp cut off for charging for the alternator and solar. Seems like a good option. Only problem is now I cannot series connect my panels and am forced to parallel to keep within Renogy's 25V solar input rating (which kinda sucks).

Also don't have an ability to have an external display.

Renogy DC DC Charger w/ MPPT

Finally reviewed it! People asked me repeatedly, and I was too busy with the solar shed. For the last few days, I tested it like crazy.. And I love it! I should have tested it months ago. Works extremely well, and it's fool proof. I pushed it to every limit, and if it cut off, it would restart...

diysolarforum.com

I tried the DCC30S unit when I was modifying my trailer for lithium as I like the single-unit design for DC-DC and MPPT. I also bought the bluetooth module to provide for bluetooth monitoring/config. While I think the unit physically did what it should, I found the bluetooth app to be a complete disaster and nearly useless. There was also a problem in that it seemed that anyone could use the bluetooth app to reset the unit back to factory defaults (including the admin password) and then reconfig the unit however they wanted. I cannot remember now if there was a way to prevent this through changing the pairing password. Another challenge was that the unit will try to trickle charge your tow vehicle's battery if the trailer battery was fully charged. I had a concern about possibly overcharging the TV's battery and there did not appear to be any way to turn this off.

I ended up returning it and going with Victron Energy's Orion-Tr Smart 18 and their SmartSolar MPPT 75/15 and so far I'm very happy with this solution.