Charging a leisure battery query

[snax]

Ok first off I know the correct ways of doing this, but I wondered if in theory this is possible.

I have two batteries in the van, the main one under the drivers seat and a leisure battery under the passenger seat, the leisure battery eventually goes flat and I need to recharge it.I cant get the van outside the house so I cant run a power cable and use a battery charger. To take the battery out means unbolting the swivel base...I can do that but well I just don't wanna that often.

However what I do have in the van is a power invertor that came with it,so my theory is this (slow afternoon at work), is it possible to connect the invertor to the main battery ,plug in a battery charger to the invertor and connect that to the leisure battery to charge it? I mean when driving of course or would the charger pull more than the alternator is giving to the main battery and flatten it?
Did that make sense?
I know the alternatives, split relay etc ,take the battery out etc , im just asking if this is possible with I have available to me currently (see what I did there...)

[RobH]

I guess it *could* theroretically be possible, however you'd lose efficiency changing 12 to 240 and back to 12v and you'd need to remember to connect and deconnect when running/ not running, it would be much betterer to just fit a simple relay.

[CovKid]

Relay - cheapest, simplest way to do it. I know you're aware of it. Best solution though and cheap.

[CJH]

Snax - you seem to be describing Ghost's Poor Man's Sterling Charger (read on from that point in the thread). The advantage this approach seems to have is that the leisure battery gets the correct level of charge (from a smart mains charger) regardless of the alternator output voltage and the starter battery condition.

[ssnax]

Cheers guys,yes i am aware of the relay and have ordered one ,as i said this was just a theory really with what i have available to me right now,sat down with one of the guys at work this afternoon and did the maths...came out as possible depending on different factors .Will work my way through that thread now

[Ralf85]

Unfortunately you don't say which conversion you have. In my westie (LHD), I move the left hand seat to two of clock and slide it off it's runners. Turning the swivel base 180% then allows the battery to be removed.

[ssnax]

Cheers Ralf but this was just about the charging theory ,i can get the battery out.

[Mocki]

Solar panel ! Simple easy and not as expensive as you think and you won't need to think about either battery again if you park outside - I haven't switched my split charger on since I fitted the panel .......

[clarry69]

i got a new - second hand solar trickle charger for my van off ebay for £8 delivered, i should imagine it will keep the leisure battery charged.

[ghost123uk]

Snax - you seem to be describing Ghost's Poor Man's Sterling Charger (read on from that point in the thread). The advantage this approach seems to have is that the leisure battery gets the correct level of charge (from a smart mains charger) regardless of the alternator output voltage and the starter battery condition.

Yep, what you are planning is exactly what I have set up. The inverter comes on automatically as soon as the engine is running, fed by the output of the relay. The charger is a Ring brand 12A intelligent 4 stage one. I am VERY pleased with the setup. I never did like charging batteries that have different levels of charge, in parallel. I wouldn't go back to ordinary split charge now, my leisure battery is always 100% charged.

I do have an override switch on the inverter, so I can use it when parked up, for other things (though I hardly ever have used or needed it)

Snax, one thing, how "flat" do you let your battery get, as in what voltage does it read when considered flat?