10 replies to this topic

[Wallowa]

I understand the positive reasons for having a heated Li battery during winter use; but, what are the negatives, if any other than an extra $150 cost, for choosing a heated battery?

 

Thanks...Phil

[PaulT]

The only downside that I see is loss of some capacity in cold weather due to the charge used to heat the battery is no longer available for other use and some increased complexity in the battery plus some increase in price.
 

I see it as a tradeoff that may be worthwhile depending how much you need to charge in very cold temps. 

Avid skiers may come to a different conclusion than snowbirds.

 

Paul

[rando]

There is another con to the way BB installed their heater - your battery monitor can't see the current he heater is drawing, so if the heater runs a bunch then the battery monitor will get out of sync.  

 

I have been using LiFePO4 in my camper for 4 years now in all seasons, down to single digits, and have never needed to heat the battery, even though I have a battery heater installed.   I insulated the outer door of the battery box, and keep the camper above freezing with the furnace (I have food and water in the camper).  With this, the battery stays comfortably warm.   

 

If you camp in super cold conditions and don't heat the camper, then you may want a heater for the batteries.  In general, I think there are better value options than BB and adding your own heater is pretty trivial. 

Edited by rando, 21 April 2021 - 11:59 PM.

[Wallowa]

Thanks all...yes, the slight current used to heat the battery needs to be off-set by the battery being able to receive charge from the the solar panels that hopefully not just equals but exceeds the draw...syncing the monitor is not a big issue for me since heater does not go through the shunt..

 

This Winter my camper was often well below the minimum of 32F and when away from Hawk I do not leave the furnace on..

 

A crap shoot to be sure...how much sun [solar], how cold and for how long..

 

Thanks....right now the $150 extra for a more versatile system with more options might be the ticket...

[ri-f]

Thanks all...yes, the slight current used to heat the battery needs to be off-set by the battery being able to receive charge from the the solar panels that hopefully not just equals but exceeds the draw...syncing the monitor is not a big issue for me since heater does not go through the shunt..

 

This Winter my camper was often well below the minimum of 32F and when away from Hawk I do not leave the furnace on..

 

A crap shoot to be sure...how much sun [solar], how cold and for how long..

 

Thanks....right now the $150 extra for a more versatile system with more options might be the ticket...

+1 regarding the crap shoot.

 

And as you say, if you don't spend all your time in the camper when it's freezing out and, turn your furnace off when you do go out, then a heating element or a heating pad wrapped around your battery is a worthwhile investment when the weather gets way down there. It's nice to know it will charge when the sun comes out. I have a heating pad wrapped around my BB that can be switched on/off as needed, too. The heating wrap has external wires that can actually run through the shunt first, but I didn't do that. I just ran the wires directly to the battery terminal via a conveniently accessible fuse/switch. I don't think that syncing every once in a while, when you know that you are topped off, is a bad idea. I run all my wires (except the heating wrap) through a shunt and still, even with the heat wrap switched off, every once in a blue moon I'm out of sync by a few amp hours. The solar or DC to DC can do that, but it's really no big deal. Anyway. It's nice to know the heating element is there if the battery needs it. Good luck with the switch over from AGM.

[Ted]

Where we are it is usually only the night time temps getting below freezing but it typically climbs above freezing during the day. It is my understanding that the concern with lithium batteries in below freezing temps is they don't take a charge, but they do still continue to work. We usually are camped at night and not getting any solar, so the batteries would not be getting charged anyway. In the morning as the sun rises, so do the temps. And only then does the solar kick in. So I'm not sure the heated batteries would be worth it in our location. The typical temps in your location may be much colder, though, making the heated batteries worth it.

[Wallowa]

Again...thanks all for the comments...

 

Yes, BB Li have a low temp shut-off [24F] that will not allow the battery to receive a charge.  My understanding is that if you try to charge a Li battery that is below freezing you will damage it permanently....yes, they will discharge, provide power, below freezing...

 

My matrix involves winter conditions which involve storms, snowing, breaks in cloud cover, more snowing and lower temps when skies finally clear...so often my Hawk this winter was in single digits with sun out but me off skiing...

 

Calculating the amps in and amps out is at best a WAG...so with a heater on/off switch I can at least have the option of a guess about whether or not solar or DC/DC will be coming on line during cold temps...

 

Get my Li June 4th.

 

Thanks folks for the input...Phil

[Wallowa]

Contacted Battle Born [Dragon Fly Energy?]....100ah BB battery heater will only come on if temp drops below 35F and will automatically turn off at 45F...

 

That was good news...making it "Phil Proof"...

 

Heater draws a nominal 1.8 ah.

 

Phil

[jeep364]

Contacted Battle Born [Dragon Fly Energy?]....100ah BB battery heater will only come on if temp drops below 35F and will automatically turn off at 45F...

 

That was good news...making it "Phil Proof"...

 

Heater draws a nominal 1.8 ah.

 

Phil

Seems like Winnebago's Lithionics or xantrex branded batteries have the exact same cutoffs.

 

Makes it seem like they all source the same chinese batteries and have similar "US Made and installed" BMS.  Slap on some American flags and sell it.  Obviously BB has the marketing game down but all brands seem to be pretty similar at this point.  BB, Lithionics, renogy, xantrex, etc etc

[Wallowa]

Interesting...but it might be that the battery design and how components are integrated may make a difference in the quality of the battery....so all brands may not be similar in design or construction...

 

Perhaps warranty period can be an indication of durability?