does anyone with lithium in their moho also use it as a battery bank if parked at home? can it be done?

[MisterB]

i am looking at swapping out my leisure batteries for lithium and also getting quotes for a battery bank at home. i was wondering if anyone used their on board lithium as a battery bank while at home. although when i have done some VERY basic research a 200AH battery will give around 2kw of storage capacity BUT it could be used to supplement a home batter bank (or could it?)

is it actually feasible? any drawbacks?

i assume some people may suggest just move into the motorhome a few hours a day, but the reality is, your home will still be using power anyway, so why not supplement it with 'free solar' or stored cheap energy from the grid at off peak rates? or is there a damn good reason NOT to?

if you had enough solar on the moho to top up 200AH battery and it was used to provide 2kw per day for 300 days it equates to £240 per year - so the cost of your on board lithium could pay for itself after a few years ....

or am i just talking nonsense and rambling on and on and on ......

 

[Jimbohorlicks]

I was contemplating running a cable from my van to the house to power the TV and lights just in the lounge where it gets most use, The van is parked quite close to the lounge.I could use the van inverter to run the TV.
The van roof is in daylight all the time but in winter may be just below the roof horizon first thing in the morning.
I could just try it out with a long extension lead,it would save having to move batteries about.

 

[MisterB]

I was contemplating running a cable from my van to the house to power the TV and lights just in the lounge where it gets most use, The van is parked quite close to the lounge.I could use the van inverter to run the TV.
The van roof is in daylight all the time but in winter may be just below the roof horizon first thing in the morning.
I could just try it out with a long extension lead,it would save having to move batteries about.

makes perfect sense to use it directly from the moho, our van inverter is a 2000w (peak 4000) and i know we would lose some due to 'efficiency' - but as a lot of tvs use an inverter anyway - perhaps a direct 12v feed might work? i think i saw a youtube clip from Greg Virgo where he connected his tv direct to a 12v supply - though it may have been a 12v tv and he just got rid of the transformer????

my thoughts were on hooking up the on board battery bank to my proposed battery wall/bank or are domestic battery banks 24v?

hopefully someone with actual knowledge might be able to guide me or tell me to give it up as a lost cause !!


Actually, after thinking about your idea, it could be used by anyone with solar and leisure batteries, whether they are lithium or lead acid, as you would be using the power direct from the batteries not feeding it into another system !! sort of off grid living while on the grid

 

[Riverbankannie]

The video that someone posted about the MG4 car, showed an adapter called “vehicle to load” which he said allowed used of 240v machines like a coffee machine when parked up and also he light heartedly mentioned running it into the house. However that car does not have the big advantage of solar charging, but shows it can be done,

 

[Gromett]

Complicated question, depends...

If you are talking about directly connecting your battery bank to the house battery bank so the house inverter can utilise both then the answer would be no. The domestic battery bank is likely configured at a much higher voltage than the 12V nominal you are using in your van.

If you are talking about connecting the output of your van's inverter to parallel with the output in your houses inverter. Yes, that is possible, but I am not aware of any products that do this. Both inverters would need to be synced so the phase matches. Then they would need to talk to each other to decide who is providing the most power and by how much.

The final alternative is if you use the van to power just specific circuits of the house. You could have some kind of manual change over switch so the house lights for example could be powered by the mains or the van. Not sure why you would want to do this though?

On balance I would say no, not really practical, cost effective or beneficial in a way that makes it worth doing

Just my opinion for what it's worth.

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[chaser]

Complicated question, depends...

If you are talking about directly connecting your battery bank to the house battery bank so the house inverter can utilise both then the answer would be no. The domestic battery bank is likely configured at a much higher voltage than the 12V nominal you are using in your van.

If you are talking about connecting the output of your van's inverter to parallel with the output in your houses inverter. Yes, that is possible, but I am not aware of any products that do this. Both inverters would need to be synced so the phase matches. Then they would need to talk to each other to decide who is providing the most power and by how much.

The final alternative is if you use the van to power just specific circuits of the house. You could have some kind of manual change over switch so the house lights for example could be powered by the mains or the van. Not sure why you would want to do this though?

On balance I would say no, not really practical, cost effective or beneficial in a way that makes it worth doing

Just my opinion for what it's worth.

Can I just ask a question that isn't about this exactly but why don't all electric cars have solar panels on the roof as well as new houses?

 

[MisterB]

Complicated question, depends...

If you are talking about directly connecting your battery bank to the house battery bank so the house inverter can utilise both then the answer would be no. The domestic battery bank is likely configured at a much higher voltage than the 12V nominal you are using in your van.

If you are talking about connecting the output of your van's inverter to parallel with the output in your houses inverter. Yes, that is possible, but I am not aware of any products that do this. Both inverters would need to be synced so the phase matches. Then they would need to talk to each other to decide who is providing the most power and by how much.

The final alternative is if you use the van to power just specific circuits of the house. You could have some kind of manual change over switch so the house lights for example could be powered by the mains or the van. Not sure why you would want to do this though?

On balance I would say no, not really practical, cost effective or beneficial in a way that makes it worth doing

Just my opinion for what it's worth.

your opinion i worth as much as anyone elses, so thanks, it gives me (and others) something to think about

i know some energy companies were exploring ways that EV's can support the gird at peak times, so i assume there is a way for this to be done, though i am with you on whether its actually cost effective, but as i am starting from scratch it might make it more cost effective than having to change things?

 

[Steve and Denise]

I am just messing about with our lights down our drive 36 leds x1.8 watts these switch on and off automatically, so when the van is at home it’s free lighting down our drive

 

[autorouter]

In five years time everyone will be doing it. But at the moment I don't know of any simple off-the-shelf system that does this.

It's something I'm definitely thinking about. I have 7kWh of lithium and a Victron Multiplus 3000 inverter-charger. If it was in my house instead of the MH, there would be no difficulty setting it up as a battery storage system (Victron call it ESS). I have a RaspberryPi based device that measures my house solar power, and the import/export power in and out of the grid. If I could get the two to communicate that information, there's no reason in principle why it can't be done. It's just a matter of coding, probably no wiring mods needed at all.

The existing wire from the MH EHU point could be used to send power to the house. With the right coding, it will send just enough power to run the house loads, and not export anything out to the grid. Solar 'diverters' already do something similar, sending unused excess solar power to heat a hot water tank, rather than sending it out to the grid.

 

[Raul]

i am looking at swapping out my leisure batteries for lithium and also getting quotes for a battery bank at home. i was wondering if anyone used their on board lithium as a battery bank while at home. although when i have done some VERY basic research a 200AH battery will give around 2kw of storage capacity BUT it could be used to supplement a home batter bank (or could it?)

is it actually feasible? any drawbacks?

i assume some people may suggest just move into the motorhome a few hours a day, but the reality is, your home will still be using power anyway, so why not supplement it with 'free solar' or stored cheap energy from the grid at off peak rates? or is there a damn good reason NOT to?

if you had enough solar on the moho to top up 200AH battery and it was used to provide 2kw per day for 300 days it equates to £240 per year - so the cost of your on board lithium could pay for itself after a few years ....

or am i just talking nonsense and rambling on and on and on ......

We are doing just that. The way we are doing is turn the van inverter on, and feed it on a AC in of the house inverter. The house is off grid with a 5kva multiplus2. I set the power limit on the house inverter on 6A so it doesn’t overload the van output. Works very well. When sun is back, we re charge the van via inverter charger in the van, plugged in the house outlet from the garage. Soon we will have a EV, that will only be charged by solar. I will have a charging station with a AC sensor, to detect solar production for charging, or throttle back whe SOC is low. That way I don’t deplete the house bank to charge the EV. Depending on the hardware you got, the van battery bank it’s a perfect solution for house energy storage when at home. In our case, this was designed from beginning to allow the van feeding the house.

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[autorouter]

i know some energy companies were exploring ways that EV's can support the gird at peak times, so i assume there is a way for this to be done, though i am with you on whether its actually cost effective, but as i am starting from scratch it might make it more cost effective than having to change things?

There is a recent standard for EV charger units, that has 'Vehicle-to-Home' (VtH) capability, and some of the newer EVs have the required 'bi-directional' charger built into the vehicle - including the later Nissan Leaf. Eventually it will be widespread and useful, but there's not many around right now.

 

[grasscutter]

Our van is parked right outside our front door so every time we make a cuppa we use the electric kettle in the van. Also boil water and put into flasks for washing up.
Every little helps these days

 

[Gromett]

Can I just ask a question that isn't about this exactly but why don't all electric cars have solar panels on the roof as well as new houses?

The amount of solar you could add would do little to range of a normal sized electric car. It would add weight though and cost.

 

[Gromett]

your opinion i worth as much as anyone elses, so thanks, it gives me (and others) something to think about

i know some energy companies were exploring ways that EV's can support the gird at peak times, so i assume there is a way for this to be done, though i am with you on whether its actually cost effective, but as i am starting from scratch it might make it more cost effective than having to change things?

That is called V2G and is practical because a car battery is 400V or 800V. This will simplify connecting back to the grid. Also a car has a lot of energy 50Kwh or more so it is worth the grid messing around to say get 5KWh off you in high demand periods.

In your OP you were talking about you leisure battery I presume?

 

[Gromett]

There is a recent standard for EV charger units, that has 'Vehicle-to-Home' (VtH) capability, and some of the newer EVs have the required 'bi-directional' charger built into the vehicle - including the later Nissan Leaf. Eventually it will be widespread and useful, but there's not many around right now.

The great thing about that is it looks to be a standard that most if not all manufacturers will accept. But again different thing to what they OP was talking about as his leisure battery is 12v and a car battery is 400V (or 800v)

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[Raul]

Can I just ask a question that isn't about this exactly but why don't all electric cars have solar panels on the roof as well as new houses?

There is actually a law that new built comes with charging EV point and solar. In the past, all new built came with 2-3kw each to raise the EPC. It’s been going for few years.
On the car, some have retro fit a panel on the roof for the 12v battery that keeps the electronics working, but not for propulsion of the car.

 

[BobJayne]

This looks an ideal conversion.
It has an extremely large inboard water tank too, or maybe black waste tank!
It was on Million Pound Motorhome tonight.

 

[dunnah01]

Big brands inverters should be grid phase sensing at the price they charge for them. A simple hook up connector and earth system from the van inverter to the house consumer unit would then work.

 

[Raul]

Big brands inverters should be grid phase sensing at the price they charge for them. A simple hook up connector and earth system from the van inverter to the house consumer unit would then work.

It’s not about big brand, but the TYPE of inverter. Big brands does inverters that synchronise, and inverters that don’t. The ones that have AC input it’s the ones that synchronises to the incoming power. That power can be: grid, generator, or another inverter. And some have even two AC inputs, and two AC outputs, with different purposes.

 

[autorouter]

The great thing about that is it looks to be a standard that most if not all manufacturers will accept. But again different thing to what they OP was talking about as his leisure battery is 12v and a car battery is 400V (or 800v)

A bi-directional charger is needed whether the vehicle is charged by AC or DC. For AC, the bi-directional charger goes in the vehicle. For DC, it goes in the charging post.

But that's not relevant to the OP's question. Victron Multiplus Inverter/Chargers are bi-directional. They are used in house installations for battery storage, and can for example feed excess solar power into the grid. They could be used to take power to/from the house if it's off-grid, like Raul's setup, and also could be used even if the house is connected to the grid.

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[Raul]

Indeed, I was gonna mention the bidirectional charger it’s a must on EV, otherwise won’t work. And I think most are not, unless mentioned.