Well you could always adapt a split charger to plug into the cigarette lighter socket, but unless the socket goes of with the ignition then you would have to remember to unplug, save draining the car battery, this is somthing I am going to experiment with, I have just to-day picked up a CTEK ZAFIR 90 mains charger, £35 from COSTCO inc the vat, which promises to all manner of good things to my leisure battery, so that may work better than the split charger, I did wonder why CTEK don't offer a charger that will run of the cigarette lighter, no one seems to offer such a device, having a leisure battery on constant charge in the boot of the car, would mean that you don't need such a big leisure battery as in theory, it is always being topped up when not in use, very handy when EHU is not available me thinks.
Forgot to mention, that I can't see any problem with running my mains CTEK charger of an inverter via the cigarette lighter for in car use, to keep the leisure battery topped up and conditioned?.
You would have to keep the car engine running, so I'd look at just connecting the car battery direct to the leisure battery with jump leads. I'd probably only do it if the leisure battery is partially full already to avoid overheating it's plates.
Your solution is sound, but I think barabbas and myself are looking at ways of keeping the leisure battery charged whilst on the move, your idea would work if you could mount the leisure battery in the engine bay, not easy with modern day cars, and I don't think having jump leads trailing from under the bonnet, into the car would be a good idea either, just a thought that went through my mind after your comment!.
then battery charger into the inverter to charge leisure battery
is this ok or will i damage something
Years ago Labcraft's, 'TP2' packs were the answer - a battery box with a built in charger that could be plugged/unplugged into the car wiring as required. They came with a male/female plug, one of half of which was wired in the boot (usually via a direct postive wire to the car battery), while the other half was on a cable running to the TP2 charger.
They could sometimes be temperamental - but, on the whole, worked very well. When going out for the day you just put the battery pack into the boot and charged it up as you drove around, then returned it to the caravan when you arrived back.
That was back in the days when caravans were much less sophisticated (and very few had dedicated battery lockers)
Like many other good ideas the TP2 seems to have vanished in recent years
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EDIT - just seen one on Ebay (no, not mine)
Item Number 160339151253
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EDIT EDIT - had a look a some previous sales, and one recently went for £56!! - I threw one away a coupe of years back when clearing out the garage! B*gger!!
Post last edited on 04/06/2009 22:30:21
------------- 'If it ain't broke, don't worry - it soon will be'
A split charge relay would charge the leisure battery in the boot, if needed. Only one cable would need to be run from the relay to the battery then earth the battery in the boot.
Just a thought could you wire an inverter directly from the relay, this would allow more power than a cigarette lighter plug, and would not run the vehicle battery flat.
The inverters usualy state not suitable for battery chargers. The voltage can be a bit unstable sometimes, This will make a battery charger unreliable and potentially damage the battery you are charging.
Much better with a set of jump leads or a proper vented box in the boot.
Im a bit lost here- why a charger- why jump leads?? Imho a cig lighter plug/lead with two croc clips would be fine, as long as car was running, and batt was pref in boot- in case of fumes/ spillage. Most chargers only have light guage wires, and if the leisure batt only needs topping up then the current it would draw would be minimal.
Your solution is sound, but I think barabbas and myself are looking at ways of keeping the leisure battery charged whilst on the move, your idea would work if you could mount the leisure battery in the engine bay, not easy with modern day cars, and I don't think having jump leads trailing from under the bonnet, into the car would be a good idea either, just a thought that went through my mind after your comment!.
Fair comment. A mate of mine put the second battery in the boot of his car and ran wires back from the car's charging circuit. If I remember right, he put a switch in line as well.
Quote: Originally posted by V8trikemids on 05/6/2009
Im a bit lost here- why a charger- why jump leads?? Imho a cig lighter plug/lead with two croc clips would be fine, as long as car was running, and batt was pref in boot- in case of fumes/ spillage. Most chargers only have light guage wires, and if the leisure batt only needs topping up then the current it would draw would be minimal.
If the battery was really low it might overload the lighter socket & fuse. Alternators give out 50 - 100+ amps a lighter socket may only have a 10a fuse.
Lots of the accessory plugs are only rated at 1amp, Thats why they use light gauge wire.
On the other hand, if the leisure battery is as flat as a pancake, the 50-100Amps from the car charger might be a bit too much and overheat the plates. So probably best to keep topping it up this way.
My understanding is that car batteries are built to take this abuse, but not leisure batteries.
I have a single electrics towbar and a small box trailer with a 12v light inside. I use a secondary 85AH battery in a NUMAX battery box that we run the fridge box off when we stop or am camping overnight.
We use a 850W generator and a 10AH intelligent charger but not all the time so it would be great if I could charge the secondary battery whilst we are on the move. Can I leech off the 12v internal lighting feed inside the trailer direct to the 2nd battery when we are on the move. Maybe using one of the self-switching combination relay as mentioned earlier?
You would have to keep the car engine running, so I'd look at just connecting the car battery direct to the leisure battery with jump leads. I'd probably only do it if the leisure battery is partially full already to avoid overheating it's plates.
Hello, hope this thread is still alive!! Have been googling for over a week to find the best items to go easy but mostly wild camping...want to be away from everything. Have a gas cooker bought cobb bbq got drive away awning to fit on to van (not camper but its only to stop the dog escaping) thought it all through as we were hardened campers for 10 years but not been for over 12 years but need to run our electric coolbox (99% to keep the dogs meat right not ours) so the obvious cheapest answer is a leisure battery but did not realise how much power the coolbox would take out of it. Have looked at solar power and generators etc but think if poss charging straight from jump leads would be best and most affordable option.
Can someon tell us how long to run the coolbox on the battery before charging and how long it would take from the van (using jump leads) it would take to re-charge.
Any help truly appreciated as I feel out of my depth for once on this one...Thanks
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Topic: Leisure Battery - is this possible!
