MegaSack DRAW - This year's winner is user - rgwb
We will be in touch
Following on from this thread:
http://singletrackworld.com/forum/topic/campervan-leisure-battery-question
After some thought I think my plan is to install an electric hookup to the van (and replace the current leisure battery, hopefully under warranty).
Now, we have no need really to run anything 240v in the van (barring maybe a fanheater in winter), so the thought is to install hookup to continually charge the battery via a proper battery charger and probably also a single 240V socket.
When we're away for more than a couple of days the fridge, stereo, LED lights and water pump will continue to work from the battery as now, but the battery will be on charge from the hookup. If we're just away for a couple of days, the hookup won't necessarily be needed as the battery will be fully charged from the off (before we leave) and we'll be cleverer about turning stuf off if the battery is getting low.
So, a few questions:
1) Does this sound like a reasonable approach?
2) Will it cause a problem if the battery is being charged by the charger and discharged by the fridge etc at the same time?
3) Should I disconnect the split-charge relay that's in place at the moment?
4) Any recomendations for a charger suitable for a 'permanent' installation?
Is it 'ok' to charge and discharge a battery at the same time?
Why ditch the split-charge system - isn't just running the electric straight off a 12v convertor from the hook-up prefereable?
[i]Is it 'ok' to charge and discharge a battery at the same time?[/i]
I don't know, hence the question.
[i]Why ditch the split-charge system - isn't just running the electric straight off a 12v convertor from the hook-up prefereable? [/i]
Again, I don't know, is it?
I guess what I want is:
1) Hookup running the 12V stuff for longer stays
2) Leisure battery running the stuff for shorter or 'wilder' days
3) A method, from the hook-up, of 'properly' charging the leisure battery as, from what I've been told, the split-charge doesn't really do that
4) The ability to run some 240v stuff from time to time.
Sounds reasonable, but without a hook-up you won't be able to run any 240V goods without an invertor.
You want a zig unit
[i]but without a hook-up you won't be able to run any 240V goods without an invertor[/i]
There'll definetly be a hook-up, and a 240V socket in the van.
[i]A method, from the hook-up, of 'properly' charging the leisure battery[/i]
seems odd as that's exactly what it's there for?
Our caravan was fine running it the way you suggest and I'm sure that the electrics ran off the mains connection when it was available, not the leisure battery.
do you have the leisure batterty charging whilst the 'van motor is running too?
oh and you should run the fridge from the mains rather than 12v IMHO
I think we might be talking at crossed-wires here (pardon the pun).
Current set-up is a split charge realy charging the leisure battery when the engine is running. 12v stuff runs off that battery. No hookup. Current battery is fried from being run-flat too often (on longer stops, where it was run until it was flat, usually after two/ three days and mainly from the fridge).
So, I want a method of running stuff for when we're stopped for more then two or three days, hence the hookup, but I also want to be potentially 'free' from hookup on shorter stops.
Advice on the other thread was that 'proper' battery chargers are better for the battery than the split-charge system. If the battery can be charged directly from the hookup, either while we're away and at the same time as the hookup is running the fridge etc, or via a lead from the garage at home, so much the better.
<edit>[i]oh and you should run the fridge from the mains rather than 12v[/i]
It's a 12V compressor fridge
'proper' battery chargers
You want a zig unit
The zig unit will take a feed from the van (the one currently going through the split charge relay) to charge the battery when moving - google twin caravan electrics for an explanation.
Ah, gotcha. But that still only leaves me with a couple of days of fridge time from the leisure battery.
I suppose I'm still at the same question: can I charge a leisure battery at the same time that it's being discharged by other stuff. I suppose at the moment that is what's happening when I'm driving - it's being charged by the split charge but it's still powering the fridge.
Is it 'ok' to charge and discharge a battery at the same time?
Yes. What happens is that if you're drawing more current than the charger provides you discharge the battery. Less and your battery remains charged and all power comes from the charger.
Whoop! That's the answer I was after 🙂
So then, a system as below should work then:
240V hookup -> 240V (decent, staged?) battery charger -> Leisure battery -> 12V stuff
[i] and in parallel[/i]-> 240V socket -> 240V stuff
If there's no 12V stuff running, the battery gets charged, if there is some 12V stuff running then it gets charged more slowly (or not at all). If the hookup isn't connected, all the 12V stuff runs off the battery and the 240V socket doesn't work. Simple. Probably.
A caravan works like this when its on electric hook up.
The leisure battery is being charged but certain items such as some lights,fan and water pump are still 12v so are draining the battery.Works ok on caravans.
Caravan fridges also run of 240V too.. I wonder if it works better off 240V than 12?
Run ya fridge on gas I do gets even colder with gas most of them do run of gas why are you messing about with the charger anyway if you can plug in on site when you get there you hook it all up put it on 240volts and your battery will trickle charge on its own and if it doesn't your battery's faulty or a fuse ???? Cheers Andy
[i]Caravan fridges also run of 240V too.. I wonder if it works better off 240V than 12?[/i]
[i]Run ya fridge on gas I do gets even colder with gas most of them do run of gas [/i]
It's a 12V compressor fridge, no ability to run on 240V or gas.
[i]why are you messing about with the charger anyway if you can plug in on site when you get there you hook it all up put it on 240volts and your battery will trickle charge on its own[/i]
The battery will only trickle charge when hooked up (and indeed that's what I want it to do) if there's a charger to charge it. I can't just attach 240V +ive and -ive wires to the battery terminals...
joeegg - good point, I hadn't thought about it like that.
I think there might be a problem in that the fridge may draw more than the charger can provide, so may eventually flatten the battery even when it's being charged. You'd need to look at the numbers to be sure though - I assume that's why caravan fridges run directly from the 240v (or Gas) when on site.
I wondered that. I've just had a look at the specs of the fridge on the interweb it's 45W, which at 12V and with my maths gives a draw of just under 4A.
Saying that, there would seem to be this doo-hicky that I could fit that would automatically swap the fridge between 240V and 12V:
http://www.cooltechleisure.co.uk/power_products/waeco_mps35_mains_adaptor_P69.html
It would appear that the zig units are rated from 12.5 amps, so would probably be OK - that fancy charger unit looks like a good idea idea though.
Do you need automatic switching? A mains 12v power supply is under £10, just unplug the cigarette socket and plug the mains supply in when you are on hook up, swap back when you start moving. It's more of a faff so it depends how often you move around.Saying that, there would seem to be this doo-hicky that I could fit that would automatically swap the fridge between 240V and 12V:
EDIT: £15 at maplin, probably less on ebay: http://www.maplin.co.uk/12v-5a-car-socket-power-supply-42702
[i]Do you need automatic switching?[/i]
Not necessarily, but by the time I've bought a hook-up kit (£100ish)and decent charger (£100ish), possibly even a new battery if they won't replace it on warranty (£100ish) and messed about fitting and making a neat job of the wiring/fusebox wotsit/sockets etc, for an extra £50 I might as well do a 'proper' job.
You should never use more than 50% of your battery's capacity, so if you want a 4 amp draw for 24 hours (96Ah) you will be needing at least 200Ah of battery capacity -= and even then you will have to charge immediately.
We run 2 x 120Ah leisure batteries charged via split charge and mains hookup when parked up at home. How well this works for you depends upon your pattern of usage. We have managed 6 week alpine roadtrips with no hookup or power deficiency. We never use hookup (always "Wild") in Scotland at the weekend and the Eberspacher doesn't seem to make a noticable dent in capacity.
The major difference is our fridge is 3-way, and runs on gas when stopped and 12V on the move. A 4 amp draw is a lot for a constant drain.
Go for the best integrated system you can manage and seriously consider a gas fridge, although there will be installation issues to consider to ensure a safe exterior-only vented installation.
The money might be better invested in a new, gas fridge. Everything else (chargers, lighting, TV, etc) will run happily on a battery so you can keep your existing set-up, have a bit more freedom where you park and save hook-up fees.Not necessarily, but by the time I've bought a hook-up kit (£100ish)and decent charger (£100ish), possibly even a new battery if they won't replace it on warranty (£100ish) and messed about fitting and making a neat job of the wiring/fusebox wotsit/sockets etc, for an extra £50 I might as well do a 'proper' job
Cheers for the input chaps. Unfortunately I can't really go the gas fridge route without a serious reworking of the interior.
I reckon with the setup I have in mind I'll get three days' worth of 'unhooked' power (so good enough for weekend trips) and for anything longer we can hook up.
Edit - just saw your last post.
Solar panel for additional charging?
Yeah, thought about that TJ, but
a) they're pretty expensive anyway and
b) if we're somewhere where it's dead sunny, so hot, so the fridge will be working a lot, we'll want the van in the shade. A permanent fix one would therefore not really be suitable, and a standalone one out in the sun risks being nicked (see (a))
go outdoors or towsure do a cheap ~£30 campers mains hoook up kit this has 3 240v plugs on the end with an RCD and a blue 16a camping socket on the other, fit the plug end in your camper and run cable through wall/floor of van (fit grommet to prevent chaffing) and plug tother end into campsite hookup..
Fit a socket outside your house of the mains ring to charge at home.
Fit a 20A 3stage charger (~£70)- (dont fit a ctek small charger you need ~20a output to be able to charge batt and feed 12v appliances at same time) into the camper and wire with as big a cables as possible direct to the leisure battery, leave the existing split charge in place..
Plug into mains at home for a few nights before your trips to fully charge LB, plug in on site if available..
Dont bother with Zig panels, overpriced and not designed for decent batt chargers ie ~20a.
Cheers, that's useful. Those kits look good actually, if only to be able to be used for parts (can't believe a 'separates' kit is twice the price)
Care to recommend a suitable 3stage charger?
Just remember you might only get a 5amp supply on the continent, so you arent going to have a lot 'spare' for charging when the fidge is running on 12V. You also need a 2 pin plug. I think our charger is a CTEK.
Yeah, thought about that. If we're plugged in, and I fit one of those auto-switch wotsits on the fridge, the fridge will be running on 240V. That means that all that will be running off the battery will be the water pump, lights and (occasionally) the stereo i.e. basically b*gger all. So, there should be enough 'spare' on the hookup (especially overnight) for charging the battery and keeping it in a tippety-top condition for when we're camping off the grid in the wilds of Gloucestershire.