Lead-acid battery for storage instead of Lithium

[John & Diane]

Replacing Lithium w/lead-acid for winter storage?
Having recently down sized from a 2015 Windsport to a 2024 Thor Compass I'm trying to figure out the best way to safely deal with the Relion, RB100LT lithium battery. We live in northern Ohio and have already had night time temps in the single digits. I contacted Relion and was told that considering the temperatures we normally get, I should remove the battery for the winter storage and store it where it will be warmer. I store our coach on our property and have always kept our other motorhome plugged in while in storage. I want to be able to exercise the generator and have lights, etc. occasionally this winter so I'm considering taking the lithium battery out and putting a marine lead-acid battery in it's place. (already have one from our winterized boat). The converter we have automatically adjusts the charging profile for the battery type installed.


Am I missing anything??? I'm really new to all the new technology and will appreciate any information/suggestions.


John

 

[ducksface]

Ihttps://www.amazon.com/s?k=rv+tank+...=rv+tank+heating+pad,aps,195&ref=nb_sb_noss_1

These come in your choice of 12v or 110v.
They work equally well on batteries just as they do on tanks.(the ones I use to heat the batteries are tied to my tank heaters switch just for the ease of it all)
Built in thermostat.
Place under battery or wrap battery...your choice.

I always try to post picture proofs so you'll all know my posts aren't Google warior based but instead are experience based.

Buy your choice of these.
And
Ask ReLion if they have low-temp cutoff in the bms.
All but the cheapest of the newer Chinese batteries have this.

 

[DavidEM]

Your plan to swap out the Li battery for a lead acid one for the winter storage area makes sense. But if you have a low temp cutoff for your Li battery-as noted above, you can just leave that in place.

And as long as you have shorepower hooked up, the converter/charger should supply most DC needs even when the low temp cutoff is in effect.

One thing you won’t be able to do is start the generator with the low temp cutoff in effect. But just wait for a warmish day when the low temp cutoff is not in effect and the generator should start ok then.

David

 

[ducksface]

Would the generator start using the chassis battery and the emergency switch?
Lithiums would be off line but the bim or bird should/could bypass them allowing the generator to start....

 

[DavidEM]

Would the generator start using the chassis battery and the emergency switch?
Lithiums would be off line but the bim or bird should/could bypass them allowing the generator to start....

Yes, I think you are right, the generator should start using the emergency switch to send chassis battery power to start the generator.

David

 

[Chateau_Nomad]

Replacing Lithium w/lead-acid for winter storage?
Having recently down sized from a 2015 Windsport to a 2024 Thor Compass I'm trying to figure out the best way to safely deal with the Relion, RB100LT lithium battery. We live in northern Ohio and have already had night time temps in the single digits. I contacted Relion and was told that considering the temperatures we normally get, I should remove the battery for the winter storage and store it where it will be warmer. I store our coach on our property and have always kept our other motorhome plugged in while in storage. I want to be able to exercise the generator and have lights, etc. occasionally this winter so I'm considering taking the lithium battery out and putting a marine lead-acid battery in it's place. (already have one from our winterized boat). The converter we have automatically adjusts the charging profile for the battery type installed.


Am I missing anything??? I'm really new to all the new technology and will appreciate any information/suggestions.


John

The "LT" in the battery model number means Low Temperature... meaning those are designed to function in well below freezing temperatures. Do a Google Search and read the specs for your battery. I'm just south of Columbus, so we don't get the snow northern Ohio gets, but we definitely get the low temperatures.

I have 3 lithium batteries with built-in heaters and low temperature charging cutoff controlled by the batteries BMS. The motorhome sits out behind our house all winter with only rooftop solar charging. They have been fine... this is the second winter, and not even a hiccup.

My suggestion is to just USE your batteries! They have internal temperature control, so you won't damage them. Mine stay charged at 100%... supposedly a no-no by LiFePO4 gurus, but the supposed calculated capacity loss over TEN YEARS is miniscule.

I spent a lot of time, effort and cash installing my lithium setup. Now I just want to USE it! There's enough hobbies connected to the motorhome... especially all the proper maintenance. My intention is to NOT make the lithium batteries another tedious hobby!

I fire up the generator and motorhome engine once a month. The truck engine runs for a half hour, and the generator runs (under load) for at least an hour. The rest is simply inspection for leaks, etc. DONE.

 

[dkoldman]

The "LT" in the battery model number means Low Temperature... meaning those are designed to function in well below freezing temperatures. Do a Google Search and read the specs for your battery. I'm just south of Columbus, so we don't get the snow northern Ohio gets, but we definitely get the low temperatures.

I have 3 lithium batteries with built-in heaters and low temperature charging cutoff controlled by the batteries BMS. The motorhome sits out behind our house all winter with only rooftop solar charging. They have been fine... this is the second winter, and not even a hiccup.

My suggestion is to just USE your batteries! They have internal temperature control, so you won't damage them. Mine stay charged at 100%... supposedly a no-no by LiFePO4 gurus, but the supposed calculated capacity loss over TEN YEARS is miniscule.

I spent a lot of time, effort and cash installing my lithium setup. Now I just want to USE it! There's enough hobbies connected to the motorhome... especially all the proper maintenance. My intention is to NOT make the lithium batteries another tedious hobby!

I fire up the generator and motorhome engine once a month. The truck engine runs for a half hour, and the generator runs (under load) for at least an hour. The rest is simply inspection for leaks, etc. DONE.

This just sounds right to me. I would accept the risk if something is not exactly as battery mfg recommends. I am still waiting to learn via experience what the freeze impact will be in my Lithium battery? The way I see it, there is no damage because if freezing the battery will not accept a charge because the MS would prevent. If one did not wish to trust the BMS, couldn't they just put the RV in store mode, or if just drop a heat lamp or small heater in battery compartment and forget about it.

 

[dkoldman]

Yes, I think you are right, the generator should start using the emergency switch to send chassis battery power to start the generator.

David

I know he is right, twice on two different coaches at a TMC dealer, the Salesman had me hold the Emergency Switch while he went back to the Firefly monitor panel to manually start the generator. It worked both times, but you need two people to do this.

Now if all the TMC have the BIRD thing, I am not sure why you have to hold the emergency switch? I thought if in use mode the house & chassis were suppose to be connected for TMC?

 

[Chateau_Nomad]

I know he is right, twice on two different coaches at a TMC dealer, the Salesman had me hold the Emergency Switch while he went back to the Firefly monitor panel to manually start the generator. It worked both times, but you need two people to do this.

Now if all the TMC have the BIRD thing, I am not sure why you have to hold the emergency switch? I thought if in use mode the house & chassis were suppose to be connected for TMC?

Not continuously connected... at least with my BIM they aren't. The BIM's purpose is to prevent the chassis battery from dropping below a certain voltage. It monitors voltage of both house and chassis batteries. If chassis drops, the BIM connects to draw current from the house batteries.

Conversely if the house batteries voltage is LOWER than the chassis battery, it WILL NOT connect automatically. So... if the house batteries are dead, the chassis battery is isolated... until the E-start switch is pressed manually connecting the two banks.

 

[phalexander]

As an alternative you could put a warming blanket on the battery since you keep the coach plugged in. It’d be easier and effective.

 

[John & Diane]

Today I removed the lithium battery and replaced it with my boat battery. Since there was plenty of slack in the cables it turned out to be an easy job that took about 10 minutes. Hardest part was carrying the boat battery to the motorhome. So far every thing seems to be compatible, fingers crossed!



Thanks everyone for your suggestions. I'm still looking for a battery blanket specific for lithium batteries. Several I found specifically stated that they weren't recommended for lithium batteries. I think they get too hot and can damage the case of a lithium battery. I was really surprised how much lighter the lithium battery was compared to the boat battery that was physically much smaller.

 

[dkoldman]

Today I removed the lithium battery and replaced it with my boat battery. Since there was plenty of slack in the cables it turned out to be an easy job that took about 10 minutes. Hardest part was carrying the boat battery to the motorhome. So far every thing seems to be compatible, fingers crossed!



Thanks everyone for your suggestions. I'm still looking for a battery blanket specific for lithium batteries. Several I found specifically stated that they weren't recommended for lithium batteries. I think they get too hot and can damage the case of a lithium battery. I was really surprised how much lighter the lithium battery was compared to the boat battery that was physically much smaller.

We had freezing temperatures in the forecast last night, I simply turned the switch on my power pedestal off. I don't care if hit -10F my lithium batteries will not be damaged.

If I was on a trip and it was -10F and I needed the house battery it would likely be 40 - 50 in battery compartment due to heat to keep RV warm. Worse case a simple blanket, heat lamp or small electric heater on very low would work assuming one did not want to invest in the pads recommended by the Duck above.

I may be misguided, but I view the objective is to simply not charge the batteries if battery is freezing? I don't see as a big deal because in most cases even if you mistakenly try to charge, the BMS will not allow you to.

 

[Chateau_Nomad]

Today I removed the lithium battery and replaced it with my boat battery. Since there was plenty of slack in the cables it turned out to be an easy job that took about 10 minutes. Hardest part was carrying the boat battery to the motorhome. So far every thing seems to be compatible, fingers crossed!



Thanks everyone for your suggestions. I'm still looking for a battery blanket specific for lithium batteries. Several I found specifically stated that they weren't recommended for lithium batteries. I think they get too hot and can damage the case of a lithium battery. I was really surprised how much lighter the lithium battery was compared to the boat battery that was physically much smaller.

??? Why? The batteries evidently have internal heaters controlled by the BMS. They're designed to be used in below freezing temperatures. Removing the batteries, adding additional heat or jumping through any other hoops is unnecessary... unless you enjoy busy work.

You can safely discharge the batteries at below freezing temperatures. If the batteries start receiving charging current, they WON'T CHARGE until the internal heater has raised the cell temperature to a pre-programmed set point... by design.

So... just USE your batteries!

 

[dkoldman]

??? Why? The batteries evidently have internal heaters controlled by the BMS. They're designed to be used in below freezing temperatures. Removing the batteries, adding additional heat or jumping through any other hoops is unnecessary... unless you enjoy busy work.

You can safely discharge the batteries at below freezing temperatures. If the batteries start receiving charging current, they WON'T CHARGE until the internal heater has raised the cell temperature to a pre-programmed set point... by design.

So... just USE your batteries!

I forgot you had told OP "The "LT" in the battery model number means Low Temperature... meaning those are designed to function in well below freezing temperatures."

He is extra protected, I don't even have low temp batteries, but I am never taking them out. Lots of myths and misunderstandings that originate from a lot of misinformation.

 

[Beau388]

Most all LFP batteries can be discharged without harm from -4 F to 140 F. Discharging LFP battery heats them (exothermic chemical reaction). Normally, discharging a battery 10% at 20 F will heat the battery enough (above 32F) for it to accept a charge. Charging a battery will also heat up the battery.


If you are worried and have shore power, there are electric battery blankets. I prefer the Vivosum seedling heating mats with their variable thermostat.

 

[Chateau_Nomad]

Most all LFP batteries can be discharged without harm from -4 F to 140 F. Discharging LFP battery heats them (exothermic chemical reaction). Normally, discharging a battery 10% at 20 F will heat the battery enough (above 32F) for it to accept a charge. Charging a battery will also heat up the battery.


If you are worried and have shore power, there are electric battery blankets. I prefer the Vivosum seedling heating mats with their variable thermostat.

Absolutely agree. I have heard people doing technical battery reviews say that if you need to charge a LiFePO4 battery (without internal heaters) in sub-freezing temperatures, just start discharging it. As Beau says the chemical reaction in discharging will self-heat the battery... which should trigger the BMS to start accepting charging.