Lithium battery system and cold

[Camerman]

We are in the Pacific NW and have a 19’ with a lithium ion battery/solar system (currently with RV cover on).

My understanding is that unlike lead-acid, lithium batteries don’t like being fully charged/continuous charging when it gets cold (how cold is cold?). The batteries are located in the front storage box outside.

I’m currently keeping the RV at 45-50F (7 - 10 C) inside with an electric space heater on shore power. With the battery disconnect switch in the off position, I still can run space heater/use lights, etc on AC shore power.

We have a predicted “cold spell” down to 15 F (-9 C) coming up for several days. (I think I can hear my Albertan relatives laughing.)

My questions are:
1. With the battery disconnect switch at off, are the lithium batteries disconnected from being charged by both AC and solar?
2. Would insulating around them in the storage box add any better performance if boon docking in fall/winter camping (temps around 32 F (0 C) to 20 F (-7 C)?

Thanks.

[Vermilye]

Originally Posted by Camerman

We are in the Pacific NW and have a 19’ with a lithium ion battery/solar system (currently with RV cover on).

My understanding is that unlike lead-acid, lithium batteries don’t like being fully charged/continuous charging when it gets cold (how cold is cold?). The batteries are located in the front storage box outside.

I’m currently keeping the RV at 45-50F (7 - 10 C) inside with an electric space heater on shore power. With the battery disconnect switch in the off position, I still can run space heater/use lights, etc on AC shore power.

We have a predicted “cold spell” down to 15 F (-9 C) coming up for several days. (I think I can hear my Albertan relatives laughing.)

My questions are:
1. With the battery disconnect switch at off, are the lithium batteries disconnected from being charged by both AC and solar?

If Escape is doing the same now as in 2017, with the battery disconnect switch off (open) the converter is not connected to the batteries. The solar connects directly to the battery and is not disconnected by the battery disconnect switch. If the batteries are below 32°F you need to cover or disconnect the panel. I added a circuit breaker/ disconnect between the panels & the solar controller.
2. Would insulating around them in the storage box add any better performance if boon docking in fall/winter camping (temps around 32 F (0 C) to 20 F (-7 C)?
Thanks.

You can use the batteries, ie take power out down to -4°F for most lithium batteries, but can't charge them below 32°F. Adding insulation won't help unless you have a heat source.

[rubicon327]

Do you have the stock Escape lithium battery offering which I believe is the GoPower Sun Cycle or something else?

As Jon said you can typically discharge down to -4F but you can't charge below 32F. Check that your battery has over and under temperature protection. If it does the battery management system (BMS) built into the battery should automatically engage and not allow charging if the cells get too cold. If you do not want to rely on this it is best to disconnect all charging sources. The battery disconnect switch does not isolate the batteries from solar charging in the stock Escape wiring configuration.

As you may have gathered it is ideal to have lithium batteries located inside the shell where you can more easily keep the space around them tempered in colder weather. Several of us that have converted to lithium have moved them inside. The battery should be fine in the outside storage box at the low temperature you mention but if you are still concerned you might consider just putting an incandescent light bulb inside the front storage box temporarily. We used to put one under a boat motor cover to keep the block from freezing if the boat wasn't winterized yet. This will should keep the space warmer around the battery. You can also consider removing the battery for the winter and putting it inside a warmer space. If you use the trailer in colder weather like we do the only long term solution is really to move them inside the trailer so they can be charged properly without the limitation of the outside air temperature. There are also batteries with built-in heating and external heating pads but they both require using some of the battery capacity to keep it warm which is a bit like chasing your tail. Only with one of these heating sources would any insulation around the battery in the front box start to make any sense.

[Lawrence A]

Originally Posted by Vermilye

You can use the batteries, ie take power out down to -4°F for most lithium batteries, but can't charge them below 32°F. Adding insulation won't help unless you have a heat source.

For "a heat source" would a battery blanket do the trick? Requires shore power of course. Here's what I'm talking about:

https://www.canadiantire.ca/en/pdp/t...p.html?loc=plp

[alanmalk]

Originally Posted by Camerman

...

My understanding is that unlike lead-acid, lithium batteries don’t like being fully charged/continuous charging when it gets cold (how cold is cold?).
...

Your understanding is correct. Most manufactures specify that continuous charging (ie "trickle" charging) and charging below 32F will damage the battery. And many specify that if the battery is not being used, that storage state of charge should be around 80%, rather than full. Check your manual.

[Perry Butler]

Originally Posted by Camerman

We are in the Pacific NW and have a 19’ with a lithium ion battery/solar system (currently with RV cover on).

My understanding is that unlike lead-acid, lithium batteries don’t like being fully charged/continuous charging when it gets cold (how cold is cold?). The batteries are located in the front storage box outside.

I’m currently keeping the RV at 45-50F (7 - 10 C) inside with an electric space heater on shore power. With the battery disconnect switch in the off position, I still can run space heater/use lights, etc on AC shore power.

We have a predicted “cold spell” down to 15 F (-9 C) coming up for several days. (I think I can hear my Albertan relatives laughing.)

My questions are:
1. With the battery disconnect switch at off, are the lithium batteries disconnected from being charged by both AC and solar?
2. Would insulating around them in the storage box add any better performance if boon docking in fall/winter camping (temps around 32 F (0 C) to 20 F (-7 C)?

Perhaps bring your batteries inside if it worries you, or put a small cube heater in your storage box. You just don't want your lithium batteries exposed to -15°F or lower where permanent damage can occur.

Food for thought,

Perry

[splitting_lanes]

Originally Posted by Camerman

My questions are:
1. With the battery disconnect switch at off, are the lithium batteries disconnected from being charged by both AC and solar?

.

No, the battery disconnect does not stop the solar from charging. You should disconnect the solar panel(s) from the controller.

It’s an easy modification that will protect your batteries from being damaged by charging when cold. Here’s a link to how I did it:

https://www.escapeforum.org/forums/f...tml#post436951

[Perry Butler]

Originally Posted by rubicon327

There are also batteries with built-in heating and external heating pads but they both require using some of the battery capacity to keep it warm which is a bit like chasing your tail. Only with one of these heating sources would any insulation around the battery in the front box start to make any sense.

Battle Born's heated battery draws power from the battery, but how long will it take to drain the battery?

SOK's heated battery only works with an outside power source to the battery, such as your camper's charger or solar system. Neither is valuable to us when boondocking.

Will Prowse doesn't believe the current heaters are worth the money in an RV situation unless hooked to shore power with the batteries in an unheated space.

Enjoy,

Perry

[alanmalk]

Originally Posted by Perry Butler

Perhaps bring your batteries inside if it worries you, or put a small cube heater in your storage box. You just don't want your lithium batteries exposed to -15°F or lower where permanent damage can occur.

Food for thought,

Perry

I'm chewing carefully here.

Quoting my manufacture:
Operating temperature Ideal for rugged & harsh environments. Much better than SLA or other lithium’s. -20'F min, +120'F max optimal operating temps (battery performs well down to -20'F). Avoid charging below 32'F.

Low temps here in Denver on Thursday are supposed to be -17F. Looks like I have a 3 degree buffer.

[rubicon327]

Originally Posted by Perry Butler

Battle Born's heated battery draws power from the battery, but how long will it take to drain the battery?

SOK's heated battery only works with an outside power source to the battery, such as your camper's charger or solar system. Neither is valuable to us when boondocking.

Will Prowse doesn't believe the current heaters are worth the money in an RV situation unless hooked to shore power with the batteries in an unheated space.

Agreed. It's an imperfect solution. I was trying to suggest that all lithium should ideally be inside the trailer shell without sounding like I was preaching and discounting other potential solutions based on how owners may use/store their trailers. Thanks for the info on SOK. I didn't realize they needed an external power source.

[rubicon327]

Originally Posted by Perry Butler

Battle Born's heated battery draws power from the battery, but how long will it take to drain the battery?

FWIW from Battleborn:
On average, the heated battery (BB10012H) consumes an average of 1.8 amps. Our tests indicate that at 0 degrees Fahrenheit, with no insulation, the heater is on about 30% of the time. With no external charging or loads it gives approximately 185 hours of heat capability before the battery goes into low voltage disconnect. With warmer temperatures you can consume less power and if you insulate your batteries you can extend the usage as well. *Please note all values are based off of a testing environment meant to simulate a battery box in cold conditions, duty cycle values and overall draw may vary based off of environmental conditions*

[7Gentex]

OP - I'm just addressing the "cold spell" aspect here:


If you have ETI supplied GoPower batts, the battery internal BMS will prevent charging below 32F (internal batt temp, not ambient), regardless if the WFCO charger, or solar, is connected to the batts or not.


If you have the newer HubLion batts from ETI, the same applies, though the HubLions have an internal heater that will activate at 30F if a charge is being supplied by sufficient solar or shore power.

[Perry Butler]

Originally Posted by 7Gentex

I'm just addressing the "cold snap" aspect here:

If you have ETI supplied GoPower batts, the battery internal BMS will prevent charging below 32F (internal batt temp, not ambient), regardless if the WFCO charger, or solar, is connected to the batts or not.
.[/I]

Pretty much all decent lithiums prevent charging below 32° F. I certainly wouldn't buy one if it didn't.

I was talking about the heater on the SOK, and a few others, using either the WFCO, other charger, or solar to run the heater, but didn't mean to imply charging. They will only charge if the battery temp can be raised above 32° F, where the BMS will allow charging.

More food for thought,

Perry

[Vermilye]

Originally Posted by Perry Butler

Pretty much all decent lithiums prevent charging below 32° F. I certainly wouldn't buy one if it didn't.

I was talking about the heater on the SOK, and a few others, using either the WFCO, other charger, or solar to run the heater, but didn't mean to imply charging. They will only charge if the battery temp can be raised above 32° F, where the BMS will allow charging.

More food for thought,

Perry

You still need to check that the BMS does shut down at low temperatures. A few manufacturers cater to home systems and save a few pennies by going with a BMS that does not include temperature shut downs.

Another reason for adding a disconnect to the solar panels is you don't want to "top off" lithium batteries during long term storage. If you have a solar system it will peak the batteries every day - OK when you are using the batteries, but something that will lessen the battery life during storage.

[Perry Butler]

Originally Posted by Vermilye

You still need to check that the BMS does shut down at low temperatures. A few manufacturers cater to home systems and save a few pennies by going with a BMS that does not include temperature shut downs.

Another reason for adding a disconnect to the solar panels is you don't want to "top off" lithium batteries during long term storage. If you have a solar system it will peak the batteries every day - OK when you are using the batteries, but something that will lessen the battery life during storage.

That's why I used the words "decent lithiums" in my previous post. There are a lot of cheap lithiums available that have a poor BMS.

My Escape has a double (+ & -) breaker/disconnect between the solar panels and the controller, and a single breaker (+) from the controller to the batteries.

The way our Escape's solar was wired was the positive went to the batteries and the negative went to the frame ground. There was always a .2 or.3 difference between the GoPower controller (or later my Victron 100/30 replaced the GoPower) and the Victron BMV-712. When I got home two months after buying the 100/30, I installed the Victron 100/30's negative to the battery, not the frame ground, and the 100/30 then matched the Victron 712's voltage.

Enjoy,

Perry

[7Gentex]

Originally Posted by Perry Butler

Pretty much all decent lithiums prevent charging below 32° F. I certainly wouldn't buy one if it didn't.

I was talking about the heater on the SOK, and a few others, using either the WFCO, other charger, or solar to run the heater, but didn't mean to imply charging. They will only charge if the battery temp can be raised above 32° F, where the BMS will allow charging.

More food for thought,

Perry

Perry, my post was not directed at you, sorry if you thought so.....I updated my post to clarify such.

I was attempting to address one of the OP's concerns for the upcoming cold weather and his batts being potentially charged when too cold................If his batts are ETI installed GoPower, or HubLion, they won't (BMS)

As he is on shore power, he could also shut off the 120v breaker for the power center/charger, but not suggested if he has internally heated batteries (HubLion and some others).

Also, he stated his trailer has a cover on it...........not usually gonna get much of a charge from the solar with that.

FYI - I run down my lithium batts SOC with a resistance heater running off the inverter for a "storage" level SOC, then switch it to shore power to keep the inside tolerable...........in the deep south.

[John in Santa Cruz]

Originally Posted by Perry Butler

...
SOK's heated battery only works with an outside power source to the battery, such as your camper's charger or solar system. Neither is valuable to us when boondocking.

...Perry

When you are boondocking, you aren't charging unless you have solar. The solar will run the heater til the battery warms up, then it will charge it.

[Perry Butler]

Originally Posted by John in Santa Cruz

When you are boondocking, you aren't charging unless you have solar. The solar will run the heater til the battery warms up, then it will charge it.

Correct, if your battery lives on the tongue or rear bumper of the camper and you're in moderate temps.

As I'm writing this it's currently -22° F or -22°F in Calgary, AB. It's a balmy -7° F here in Lanesboro.

So in our case, and others who live in the northern border states, Alaska, or Canada, in -20° to -50° F temps the battery is ruined at 7 am without solar or a power source. That's why I recommend SiO2 batteries in that and only that instance if you don't want to remove your batteries or are afraid you'll forget. Everyone else I recommend lithium.

Enjoy,

Perry

[Live In The Moment]

Thank you for the timely post. I really appreciate those of you who take the time to share their knowledge with us newbies. We managed to pick our new 21C from ETI last week between snow storms. After waiting more than a year and half to get our trailer, the pickup day was a little anticlimactic as we had to hurry home and get the trailer covered and put in storage before the next round of snow. While I am slowly gaining a little knowledge about the solar/electrical system, I still have a long way to go before I feel confident in understanding how to best manage the system. The current cold snap in the Greater Vancouver area, has also brought up a few question.

Our trailer is equipped with two lithium batteries, two solar panels, a Victron Smart Solar Controller, and a Victron Smart Shunt/Battery Monitor. My question is about the advantages of installing a solar disconnect switch vs using the solar controller to disconnect the solar panels from the batteries. Before we put the cover on the trailer, we covered the solar panels with black garbage bags so this may not be an issue this year, but in the future, is using the VictronConnect app to 'enable' or 'disable' the charger feature from the battery menu an adequate solution or is installing a solar disconnect switch the superior option?


When we put our trailer in storage, my intent was to also remove the two lithium batteries as the Hublion battery manual recommends storing the batteries at room temperature. However, with daylight quickly waning, when I removed the cover of the battery box I realized that removing the batteries was more involved than simply disconnecting the battery terminals. ETI has installed a piece of plywood on top of the batteries with the smart shunt mounted to it. Any advise on the order I disconnect these components. I plan on taking pictures and labeling all wires as I disconnect them.

My final question has to do with when the trailer is not in winter storage but not in use. (ie. Between trips - the batteries are installed and the solar panels are not covered and the trailer is not connected to shore power). Is it better for the batteries to be charged daily via the solar panels or would it be better to leave the batteries at 50 - 80% charge and use the VictronConnect app to 'disable' the charger feature? In the second scenario I would 'enable' the charge feature a few days before going away or plug in to shore power to fully charge the batteries before departing.

[splitting_lanes]

I’d use the controller to disable charging- you could use the shunt to verify that it’s not outputting anything to the batteries. My GoPower charger doesn’t reliably work over Bluetooth, so I installed a switch.

I do leave my battery at 40-70% charged in between trips, and just hook up electricity to charge it a day before.