Keeping your LiFePO4 bank warm for charging in winter- what’s the best?

[Chotu]

I was going to move my lithium bank inside, but I really don’t think I have enough time before winter hits. There are a lot of other projects going on.

So, it will remain in its on-deck outdoor battery box.

As lithium people know, we can’t charge these batteries below freezing.

So, how are people protecting these batteries and keeping them the right temperature through the coldest of winter?

What is the best way to do that these days? I know things change a lot. I have read online about different ways to do it. There are pads. There are blankets. Maybe there’s some thing I don’t know about.

How do you keep yours warm to be able to use them through the winter?

[GordMay]

1. Insulate your battery box [Armaflex, Graphite Polystyrene (GPS) board, etc?], with removable insulation [for summer use].
2. Add a battery warmer blanket [heating pad], or other heater.
3. Reduce charging current, per manufacturers' instructions
4. Some of the newer, premium Lithium Iron Phosphate batteries*, have an integrated heater, connected to the battery's internal BMS, such that if you try and charge them, when the batteries internal temps are near, or below freezing, they divert the charging power to the heater, until they are warm enough to be safely charged.

According to RELiON: When charging lithium iron phosphate batteries below 0°C (32°F), the charge current must be reduced to 0.1C and below -10°C (14°F) it must be reduced to 0.05C. Failure to reduce the current below freezing temperatures can cause irreversible damage to your battery.

* eg: RELiON’s “LT Series” [a 12V 100Ah LiFePO4 battery] is specifically designed for cold charging, utilizing charge current to heat the battery, before allowing charge. The system features proprietary technology, which draws power from the charger itself, requiring no additional components.
With the LT series, you can charge down to -20°C [-4°F].
➥ https://www.relionbattery.com/knowle...d-temperatures

When attempting to charge a Lithium battery below 0°C / 32°F a chemical reaction referred to as “Lithium Plating” occurs. Lithium plating is caused by the charge current forcing the lithium ions to move at a faster reaction rate and accumulate on the surface of the anode.

When this chemical reaction occurs, the internal resistance of the battery increases and reduces the rate of chemical metabolism. This chemical reaction causes a permanent reduction of the battery’s capacity and will continue to reduce its capacity each time this reaction occurs.

[Chotu]

Unfortunately, I didn’t opt for the built in heaters. “I’ll never be in freezing weather.” Lol.

So the pads / blankets are still the go, it seems like.

I’m hoping they can be tied into the charge controller to allow charging after they are finished and I also hope they have temperature regulation so as not to overheat or under heat the batteries.

My battery box is R7 by default. Not amazing, but somewhat ok. Surprisingly, there is no heat when charging these things so the natural insulation factor from the foam is not an issue in summer.

[JBP]

If your cold spell is short, you can simply not charge them. You can still discharge at considerably lower temps. I believe you can program victron controllers to stop charging at low temps.
I've seen people use 12V heating pads because they didn't have shore power.

[Chotu]

Originally Posted by JBP

If your cold spell is short, you can simply not charge them. You can still discharge at considerably lower temps. I believe you can program victron controllers to stop charging at low temps.
I've seen people use 12V heating pads because they didn't have shore power.

True. I was considering maybe just T-ing off a very small bit of heat from my forced air diesel heater for heating the battery box on demand. 1” heating conduit or something, with a ball or gate valve.

More of a manual thing, but cabin heating should coincide nicely with times when I need to heat the batteries.

Or… maybe just a computer fan to blow interior air out into the battery box, which shares a wall with the galley. Even more simple.

Only issue there is I’d need to leave my heat on when I’m gone more than 3 days or shut everything down (refrigerator/freezer) depending on temps.



I wonder: if I’m at a dock for the winter as opposed to at anchor, maybe i could just remove the lithium batteries from the circuit? Drop some piece of junk 12v lead acid battery in and not have to worry about it?

[rslifkin]

Originally Posted by Chotu

True. I was considering maybe just T-ing off a very small bit of heat from my forced air diesel heater for heating the battery box on demand. 1” heating conduit or something, with a ball or gate valve.

More of a manual thing, but cabin heating should coincide nicely with times when I need to heat the batteries.

Or… maybe just a computer fan to blow interior air out into the battery box, which shares a wall with the galley. Even more simple.

Only issue there is I’d need to leave my heat on when I’m gone more than 3 days or shut everything down (refrigerator/freezer) depending on temps.



I wonder: if I’m at a dock for the winter as opposed to at anchor, maybe i could just remove the lithium batteries from the circuit? Drop some piece of junk 12v lead acid battery in and not have to worry about it?

If you're at a dock with shore power, you could definitely go for that last option if desired.



For heating from the cabin heat, you could use a fan with a temperature controller so it automatically runs when the battery box gets below a certain temperature. You could do that with heat pads as well.

[Chotu]

Originally Posted by rslifkin

For heating from the cabin heat, you could use a fan with a temperature controller so it automatically runs when the battery box gets below a certain temperature. You could do that with heat pads as well.

I like this option best. The simplicity and power savings would be very hard to beat.

A temperature controlled computer fan to blow cabin heat into the battery box (and battery box thermometer to double check) would use the least power and be able to work in all conditions. It would work at anchor, dockside or anywhere really. It could even work to help cool the batteries in the summer, although that’s never been a problem.

If you aren’t winterizing the boat, you have to maintain some semblance of heating at all times inside so the water system doesn’t freeze. So this is perfect actually.

[s/v Jedi]

The helpful answer: heating pads connected to a thermostat control. Both available on Amazon.

Obvious answers: move south of Orlando; use batteries that can be charged in freezing weather (Winston cells can do it even without heaters) when not going south during winter. Move batteries to warmer ambient (inside).

Even with the heating, you increase risk of damaging batteries greatly.

[Chotu]

Ok. So they used an A-frame concept to lower the mast.

That’s a lot easier than trying to build an A-frame and then raising the mast with it.

However, it’s worth a consideration. The only problem is where do you find a no wake zone that good? Ha ha.

I will think through this though. Maybe it’s OK. But you still have to get all of that wood delivered somehow and find a place to do it. You need to be at a marina for that. So I guess the crane rental is probably cheaper and more simple? Assuming I can find a crane that can reach out over a dock somewhere.

I stepped my mast on a 45ft Gulfstar using a manual crane at Castleton-on Hudson before. It was great. Right at the dock. I think this one is too tall for that crane.

Kind of would like to just go to one place and do all of this. But I have not found that place

[s/v Jedi]

Originally Posted by Chotu

Ok. So they used an A-frame concept to lower the mast.

That’s a lot easier than trying to build an A-frame and then raising the mast with it.

However, it’s worth a consideration. The only problem is where do you find a no wake zone that good? Ha ha.

I will think through this though. Maybe it’s OK. But you still have to get all of that wood delivered somehow and find a place to do it. You need to be at a marina for that. So I guess the crane rental is probably cheaper and more simple? Assuming I can find a crane that can reach out over a dock somewhere.

I stepped my mast on a 45ft Gulfstar using a manual crane at Castleton-on Hudson before. It was great. Right at the dock. I think this one is too tall for that crane.

Kind of would like to just go to one place and do all of this. But I have not found that place

But you have a very wide catamaran, much easier than a narrow, rolly, small monohull. You can easily build those A-frames on deck, then raise them. They only need to be a little higher than halfway up the mast.

I spent 17 years on a 30’ monohull with a deck stepped mast in a tabernacle. We used two legs that attach between the forestay turnbuckle and a block and tackle to the forestay chainplate. The trouble is controlling sideways motion which is tough when your shroud chainplates are aft of the mast. But the A-frame would work. How heavy is the mast? It’s nothing.

[Chotu]

Originally Posted by s/v Jedi

Originally Posted by s/v Jedi

But you have a very wide catamaran, much easier than a narrow, rolly, small monohull. You can easily build those A-frames on deck, then raise them. They only need to be a little higher than halfway up the mast.

I spent 17 years on a 30’ monohull with a deck stepped mast in a tabernacle. We used two legs that attach between the forestay turnbuckle and a block and tackle to the forestay chainplate. The trouble is controlling sideways motion which is tough when your shroud chainplates are aft of the mast. But the A-frame would work. How heavy is the mast? It’s nothing.

I do agree with that.

There is the matter of getting all of this wood somewhere and having it delivered somewhere and being able to move it onto the boat when it is delivered.

That requires a marina and a dock. And that’s what makes it not feasible. It’s financially not feasible.

If you are spending $400 wood and ratchets and come alongs and delivery, then working with the attached transient slip rates ($2250 for a week at the dock) to build the frames… but the crane is $375/hr, it’s much less expensive to use the crane.

[s/v Jedi]

Originally Posted by Chotu

I do agree with that.

There is the matter of getting all of this wood somewhere and having it delivered somewhere and being able to move it onto the boat when it is delivered.

That requires a marina and a dock. And that’s what makes it not feasible. It’s financially not feasible.

If you are spending $400 wood and ratchets and come alongs and delivery, then working with the attached transient slip rates ($2250 for a week at the dock) to build the frames… but the crane is $375/hr, it’s much less expensive to use the crane.

That’s one way to do it, but not the feasible way. To make this work, I would anchor close to a public ramp, go to the Home Depot, rent their pickup truck for $25 to move the lumber and hoist etc. then dinghy them aboard. Zero marina cost, zero delivery fees. And the lumber you can burn in your wood stove to keep warm during the winter, which solves your hauling fuel problem in one go

[Chotu]

Originally Posted by s/v Jedi

That’s one way to do it, but not the feasible way. To make this work, I would anchor close to a public ramp, go to the Home Depot, rent their pickup truck for $25 to move the lumber and hoist etc. then dinghy them aboard. Zero marina cost, zero delivery fees. And the lumber you can burn in your wood stove to keep warm during the winter, which solves your hauling fuel problem in one go

I guess I will look into it, but that wood will need a lot of time and pressure to turn into viable diesel to heat with . Ha ha ha.

[Chotu]

I definitely appreciate the outside the box thinking and brainstorming but that one is too expensive. It’s just so much cheaper to use the crane. Way less work also.

I just have to find a place where the crane can reach the boat

[Chotu]

Here’s a pretty interesting option that I have that I didn’t even realize I had.

If I get a dock for the winter, which is likely, I already have a 12 V power supply that I can plug into the shore power:

https://www.iotaengineering.com/prod...ttery-charging

My trusty Iota 90amp converter/charger.

It will be so simple that all I have to do is disconnect the batteries from the circuit after charging them completely, remove the LiFePO4 charge controller from the DLS-90, and I have a steady 13.4VDC at up to 90amps as long as the shore power stays on

Easy!