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Discussion Starter · #1 ·
I'm planning on converting a small used Airstream (still looking) to run on LiPo batteries (induction stove etc.)

What would I need in terms of components to build a "Level 2" charger to run off the LiPo batteries so I could charge my Kia EV?

Sources for the cables, parts etc?

Thanks.
 

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I'm planning on converting a small used Airstream (still looking) to run on LiPo batteries (induction stove etc.)

What would I need in terms of components to build a "Level 2" charger to run off the LiPo batteries so I could charge my Kia EV?

Sources for the cables, parts etc?

Thanks.
No.

Need a strong 240VAc genset in there and a decent sized fuel tank.

I mean it could be done, but likely cost close to USD $20K, and you still need to charge the source bank.

Which should be LFP certainly not LiPo.

How many days do you plan to stay off grid?

Charging the House bank off the EV would be more practical.
 

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Don't listen to nay-sayers. Plenty of reasons why you would want this capability.

Check out this video for probably the easiest way to do mobile L2 charging; build a battery bank and use an off the shelf inverter. Doesn't get much more simple than that.

 

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I'm planning on converting a small used Airstream (still looking) to run on LiPo batteries (induction stove etc.)
Lithium-ion batteries for RVs are becoming popular... but why would you specifically want LiPo, and do you know what that means (lithium-polymer, meaning lithium-ion with polymer electrolyte)?

As john61ct implied, the normal lithium-ion choice for RV batteries is LFP (LiFePO4), especially if the trailer battery is to be at close to 12 volts (nominally).

What would I need in terms of components to build a "Level 2" charger to run off the LiPo batteries so I could charge my Kia EV?
If for some reason you had a ton (literally) of battery in the trailer, and the trailer already had an inverter to supply AC power to the appliances, you would simply need the same EVSE (electric vehicle service equipment, or "charging station") that you would install at home.

"Level 2" implies 240 V AC, while most RV inverters provide only 120 V AC (which is "Level 1"), but you could just use the 120 V to charge the car.

But how much energy capacity would this trailer battery have? I don't understand why it would be so huge that it could ever have extra energy to charge a car, or the power capability to charge at anything beyond a trickle (less than 1 kW sustained). I don't even know why there would be a compact electric car wandering around with this travel trailer, while the trailer is being towed by another vehicle; the Kia can't tow the trailer.

Why not charge the car from whatever power source charged the trailer?
 

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I'm planning on converting a small used Airstream (still looking) to run on LiPo batteries (induction stove etc.)

What would I need in terms of components to build a "Level 2" charger to run off the LiPo batteries so I could charge my Kia EV?

Sources for the cables, parts etc?

Thanks.
Is the Airstream going to be stationary and off grid? Or are you travelling in it? Got a big solar array in the works? Any reason you're not going with propane appliances?
 

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Discussion Starter · #9 ·
Lithium-ion batteries for RVs are becoming popular... but why would you specifically want LiPo, and do you know what that means (lithium-polymer, meaning lithium-ion with polymer electrolyte)?

As john61ct implied, the normal lithium-ion choice for RV batteries is LFP (LiFePO4), especially if the trailer battery is to be at close to 12 volts (nominally).


If for some reason you had a ton (literally) of battery in the trailer, and the trailer already had an inverter to supply AC power to the appliances, you would simply need the same EVSE (electric vehicle service equipment, or "charging station") that you would install at home.

"Level 2" implies 240 V AC, while most RV inverters provide only 120 V AC (which is "Level 1"), but you could just use the 120 V to charge the car.

But how much energy capacity would this trailer battery have? I don't understand why it would be so huge that it could ever have extra energy to charge a car, or the power capability to charge at anything beyond a trickle (less than 1 kW sustained). I don't even know why there would be a compact electric car wandering around with this travel trailer, while the trailer is being towed by another vehicle; the Kia can't tow the trailer.

Why not charge the car from whatever power source charged the trailer?
Don't listen to nay-sayers. Plenty of reasons why you would want this capability.

Check out this video for probably the easiest way to do mobile L2 charging; build a battery bank and use an off the shelf inverter. Doesn't get much more simple than that.

That's a cool video. Even with GelCells and a pretty small amount of solar, he's getting some decent charged-miles on a daily basis.

Very helpful.
 

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Discussion Starter · #10 ·
Is the Airstream going to be stationary and off grid? Or are you travelling in it? Got a big solar array in the works? Any reason you're not going with propane appliances?
The idea is for boondocking in a few years (work mobile, see the woods). By then maybe a Ford EV Pickup would make sense. If I'm sitting at a location for a week, it would be nice to be able to charge whatever EV I'm using.

And yes, I got the name of the battery type wrong.

Anyone try these packs?
 

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The idea is for boondocking in a few years (work mobile, see the woods). By then maybe a Ford EV Pickup would make sense. If I'm sitting at a location for a week, it would be nice to be able to charge whatever EV I'm using.
Realistically, the amount of energy which you collect per day from solar panels on the roof of a small Airstream will barely meet your energy requirements to live it the trailer (including cooking with electrical appliances), so charging an EV doesn't seem like a reasonable expectation.

And yes, I got the name of the battery type wrong.
Okay, that makes sense, and that's why I asked if you really meant Li-Po.
 

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The idea is to have solar on the roof and yes, LFP (LiFePO4). The idea is to be able to do a Level 2 charge on occasion.
I don't think you're likely to need Level 2, and so you wouldn't need 240 V. Unless the battery is enormous, or you're using automotive-grade cells rather than what is commonly used in RVs, it won't safely withstand much more than the 1.44 kW possible at 120 V on a 15 amp circuit anyway. Check the specs, but if the charging station and charger will allow the 24 amps continuous allowed on a 30 amp circuit, that's 2.9 kW... still at 120 V. That would be a relatively common RV inverter, and 30 A 120 V is the normal service for a travel trailer.

If considering a huge battery, with most of the load being 120 V AC (not ~12 V DC), you might consider a higher-voltage battery to avoid huge currents and the corresponding heavy wiring and high resistive losses... but then you're not using common RV components (solar chargers, inverters, etc).
 

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The idea is for boondocking in a few years (work mobile, see the woods). By then maybe a Ford EV Pickup would make sense.
It only makes sense if someone is giving you free charging for the truck. A travel trailer's solar array will never make a useful dent in the energy demands of a EV pickup like that, expecting a place to plug in for cheap charging when you are in some on-grid place away from the trailer doesn't seem reasonable, and paying for fast charging is about as expensive as buying gasoline. The economic logic of EVs is generally based on cheap electrical energy, and by the time a charging system marks it up to fast-charging prices, it's not cheap.

In "a few years" there will be multiple EV pickups to choose from, but yes, a Ford F-150 Lightning will be one of the first available.
 

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You are seriously underestimating the amount of power that solar will provide. Maybe in the frozen north it is not good, but here in the sunny US desert solar is awesome.

Just to make it easy I'll link to that solar LEAF again in his later iteration with more solar panels on a roof rack. He has roughly 4-5kw of solar on the car in direct sunlight. You can easily fit that onto a camper trailer like an airstream, probably more. Also you could make ground or roof arrays that can be angled when parked for better efficiency.

But just because the Solar LEAF actually works here's his latest video he shows that his current iteration gets him 22 usable miles of range per day in his LEAF. I'm guessing the Kia would have similar efficiency to a LEAF. Considering when traveling with a camper trailer or RV the whole point is to go some place and park for a few days and then move on to a new place, solar like this would give you real range over the course of a day or two.

 

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Discussion Starter · #15 ·
I don't think you're likely to need Level 2, and so you wouldn't need 240 V. Unless the battery is enormous, or you're using automotive-grade cells rather than what is commonly used in RVs, it won't safely withstand much more than the 1.44 kW possible at 120 V on a 15 amp circuit anyway. Check the specs, but if the charging station and charger will allow the 24 amps continuous allowed on a 30 amp circuit, that's 2.9 kW... still at 120 V. That would be a relatively common RV inverter, and 30 A 120 V is the normal service for a travel trailer.

If considering a huge battery, with most of the load being 120 V AC (not ~12 V DC), you might consider a higher-voltage battery to avoid huge currents and the corresponding heavy wiring and high resistive losses... but then you're not using common RV components (solar chargers, inverters, etc).
Yes, most of the larger 120/240 inverters want 48v.
 

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Discussion Starter · #16 ·
You are seriously underestimating the amount of power that solar will provide. Maybe in the frozen north it is not good, but here in the sunny US desert solar is awesome.

Just to make it easy I'll link to that solar LEAF again in his later iteration with more solar panels on a roof rack. He has roughly 4-5kw of solar on the car in direct sunlight. You can easily fit that onto a camper trailer like an airstream, probably more. Also you could make ground or roof arrays that can be angled when parked for better efficiency.

But just because the Solar LEAF actually works here's his latest video he shows that his current iteration gets him 22 usable miles of range per day in his LEAF. I'm guessing the Kia would have similar efficiency to a LEAF. Considering when traveling with a camper trailer or RV the whole point is to go some place and park for a few days and then move on to a new place, solar like this would give you real range over the course of a day or two.

My Kia Niro EV gets about the same miles/kwh as the Leaf. I was thinking the awning and roof of a trailer.
 

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You might run up against space for panels on the trailer. My father has a 40 foot motorhome that is just about full of solar panels, but it struggles to keep the batteries charged. In his case, he needs to leave space to walk but otherwise it's pretty full.

Part of the issue is the panels face straight up. You might also run into trouble with shade in the woods. Lots to consider, and I would have some kind of backup in case the output doesn't match the demand. Doesn't matter how much battery you have if you're using more than the panels are producing.

Edit: forgot to mention, the reason for my dad's issues is all the appliances, vents, and stacks on his rig. I have no idea how much square footage is available on top of an Airstream.
 

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Solar limited by roof size does not begin to touch the Wh per day needed to charge an EV of any decent range.

Likely often not enough for an all-electric galley, better off using propane where you can.

If you just drive the right EV to charge at a grid-fed station, then you can go back to the trailer and recharge your House bank off the car, and you won't be limited by your solar.

You need to get a handle on just the basic scale of consumption of these loads, most people camping off grid might only use half a kWh per day, a little compressor fridge using 10-30Ah is by far their biggest consumer.

Stuff you're talking about is like 60-100kWh.

You haven't floated aircon yet either :cool:

If you need these huge inputs seriously off grid for days at a time, you need a FF genset, seriously. And high fuel bills, this is not even close to portable solar territory.
 

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Please stop "educating" yourself from watching YouTubers.
Haha, no. This is just an argument from authority and it's a logical fallacy. Not an argument.

You are correct that if someone wants to have AC and a big fridge and bake bread every night they probably won't have much luck. But if they are efficiency-minded, like I dunno, an EV-enthusiast, then what's wrong with the concept?

5kw of solar is completely usable "bonus energy" for the average EV. End of story.
 
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