Off-grid power installation

[dominichayhoe]

So, I'm still pondering over what to do to have an off-grid system with working 3 pin sockets.

Be interesting to hear everyone's thoughts.

As I see it there's only really two options without going crazy, mostly because of the location of the leisure battery.

Note: I have the solar panel and victron mppt which will charge either/both systems.

1. Replace the current leisure battery with a low temperature lithium battery (which I can get 110ah for the same size as the existing battery), run the cables to the electric cupboards from it and install an inverter, B2B and mains/battery switching station (to automatically choose the correct power source, mains or leisure battery through the inverter).

OR

2. Purchase a battery back up such as a Jackery, and mains/battery switching station.

Pros/Cons

First system is more complete but limits the size of the leisure battery, means you'll probably need a low temperature lifepo4 battery and you have to run a high power cable to the electrics unit from the bonnet and you will require a B2B too.

Second system means you can use the Jackery outside the van, don't have to worry so much about the cold, and don't need the B2B, but either have to run cables in any case to charge from the alternator, or more likely move the unit when/if this is necessary. The cost of a 100w Jackery unit is similar to a lithium battery with inverter in any case. Doing this takes up space in the electrics cupboard obviously. You can't upgrade the inverter if you find it's not man enough.

Plus the fact your electrics system won't use the leisure battery at all if this unit is switched on, so you'll have to remember that if you want to use it for lights etc and only switch the Jackery on maybe if you need the 3 pin plugs. Then maybe you'd do that anyway with system 1 otherwise you're inverting your electrics to 230v to invert back to 12v for the lights etc. So I may be wondering about things that are superfluous here!

I'm sure I've missed lots, so feel free to add your comments.

I should add, I have built these systems before. My previous camper has a Lifepo4 leisure battery with inverter but no switching station and is under the drivers seat and has worked well for over a year.

 

[dominichayhoe]

1000w not 100w!

 

[mpill990]

Both are pretty good solutions - if I were doing it I'd always put the battery in the electrical cupboard.
Neater in my opinion without the long cable run, and potential voltage drop, to the front of the van.

What are you going to do about water and the toilet? We use about 20l of water a day and I reckon the toilet cassette will be full after 4 days and water empty after 5 days...


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[dominichayhoe]

Both are pretty good solutions - if I were doing it I'd always put the battery in the electrical cupboard.
Neater in my opinion without the long cable run, and potential voltage drop, to the front of the van.

What are you going to do about water and the toilet? We use about 20l of water a day and I reckon the toilet cassette will be full after 4 days and water empty after 5 days...


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Thanks, its fine putting the Jackery in the cabinet, but if you wanted to do that with an actual leisure battery youd still have to do the cable run for the alternator.

Not so concerned about the water situ as this is more for power hungry kids than Full off-site living.

 

[mpill990]

I'd go for the Jackery type solution then. Simple is always good
I wouldn't mind one to use on my home hifi system as the mains is very noisy.
This would fix that for sure.

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[far.landscape]

I started a similar thread a while back, “adding a lithium generator…” I think I called it. Someone posted a really impressive fixed solution, but it was more extensive modification than I was willing to go for.

I ended up going for a goal zero 1000x, and using it for laptop charging (which aside from the fridge is by far my biggest power draw due to the load taken for panorama merging… another story…).

Yes the goal zero is higher £/W than jackery or ecoflow, but, it fits well in the left garage cupboard plus has a bomb proof build (and I managed to get a small discount), and apparently has some good quality cells.

Note that whatever you buy, if you really want it to act as if you are on hookup, make sure the inverter is big enough to provide enough W to “pretend” it’s a 230v supply on a 6a breaker… that’s why I wanted the 1500w (continuous) inverter on the gz 1000x…

Also just be aware that due to inverter efficiency loss coupled with (in)efficiency of charging an agm, a 1000Wh lithium pack outputting via the inverter will only charge a 96 AH battery from 50% to “full” (ie adding ~550Wh)… about once before emptying! (The math and a real world test of this in my case backs that up)

 

[far.landscape]

…and btw… the way I “hook it up” is by leaving the gz in the van, using a (in my case) 3 pin uk plug adapter, and looping the lead out of the back window and in to the hook up socket!