Power options for camper van (self build)

Hi Erin, you have asked a biggie. Perhaps the best thing to do would be to read the information available in 'Topics, Power & Electrics' on this site. Look Here
Then come back here to the Forum with any specific questions. Good luck.

after my follow up to Allan and clarification of my needs, i am again wondering whether a standalone 12Volt battery system 150ah (possibly two) not connected to the main vehicle battery, and recgarged with a battery charger as required (as will mostly be in powered locations,apart from a day or two each trip) would suit my needs as detailed above.

Can any one give me any advice on how long a 12volt AGM 150ah battery wouold last using:
80L compressor chest fridge above freezing
12 volt Palsonic lcd tv (up to 3hrs per day)
Small water pump maybe 20 mins per day
3 x 42 led interior lights
Basic Sound system used a few hours per day

I am also considering running a small inverter for laptop charging.

All replies much appreciated.

Erin

Hi Erin, There are a lot of variables in estimating your power consumption. The fridge for example will vary dependant on ambient temperature and your usage. The other appliances will vary by their individual power ratings. However, taking a guess at your consumption, I would suggest the following. Other readers may have specific figures from experience but they may not mirror your appliances or usage.

For a 24 hour period:
Fridge, based on averaged continuous consumption of 2 Amps = 48 Ampere hours.
TV, say 8A for 3 hours = 24Ah
Water pump, say 3A for 20 min. = 1Ah
LED lights, say 0.5A for 4 hours = 2Ah
Sound system, say 2A for3 hours = 6Ah
Computer charging via inverter, say 3A for 3 hours = 9Ah
Giving a total of 90 Ampere hours.

With a 150 Ah battery this would be a drawdown to 40% remaining State of Charge. 50% being considered desirable for an AGM battery so a little more consumption than recommended but not too bad. Provided of course that you are able to replace that consumption by recharge the next day. You would need to do this by driving for several hours with the camper battery connected to the car alternator, or with a solar panel of perhaps 180W rating (assuming good absorption conditions), or with an adequate battery charger if mains power is available. Of course, if mains power is available, all those appliances could be supplied by the mains and a battery would not be needed at all.

Rule of thumb would also suggest that a 150Ah battery would satisfy the average conservative camp but the real issue is the ability to recharge that battery before it discharges below 50% SoC. The battery will also not always be 150Ah, with age its capacity will diminish.

Hope that helps.

I would advocate a different approach Erin, which is simpler
and I think more effective for a single vehicle scenario.
It fits in better for the more isolated type of places we tend to go.


You need 3 elements for success.

1/ Larger capacity main vehicle battery. 2*80AH overlander type batteries should do you.

2/ Secondary means of charging batteries. E.G. Permanent roof mounted solar panel 80-120watt.

3/ Warning device for when batteries get low E.G. accurate Voltmeter with alarm.

From these 3 key elements you work on the efficiency of each attached device as you can and money allows.


Some key basic points about the above.

A/ The batteries are primarily charged by the car engine, and as such the batteries are spect to accept a high short term (>60 amp) charge rate.

As you get time - A selectable means of high idle speed (1000rpm) will assist.


B/ The solar panels contribute a little but there main purpose is to provide
a way to re-charge if your batteries somehow go flat.


C/ Low battery warning devices and low volts cut outs on fridge etc are there
to enable things to be turned off before its to late.

D/ Adopt a connection standard - I use 12v cig lighter plugs (copper plated lion
type) but only because I'm into this stuff and generally re-wire everything for better performance.
There are better (Hella) type items.


As time permits accessories such as a mains charger are useful if you spend time at CV parks.
This should connect straight into your battery , but I do not know your specific van and so cannot reccomend this without testing.




P.S. Forget the 12v microwave - they are just not efficent in your senario.

So, after considering a few options, i am going to go with:

1 x 150 ah AGM house battery
Ctek dual unit connected between house and cranking battery
2x 50watt solar panels on roof (as these have been given to me)

No microwave or hairdrier :) unless connected to 240volt

LED lights in camper, 1x80l compressor fridge, small water pump, invertor to recharge laptop every couple of days.

Running the engine for an hour or so if necessary to backup solar panels.

From research this seems to be feasible. Will an auto-electrician be able to install this for me or do i need to find a solar specialist i wonder?

Hi all

I have progressed a little in my plans for powering my camper and am ready to engage a tradesman to wire it all up. Advice needed on options for mains charging in conjunction with the ctek dual as my solar panels have turned out to be no good. Eventually i would like to buy a panel or two but cost prevents it at this stage.

I have a 150ah agm house battery, and a ctek dual to charge from the main battery while vehicle is running. My question is what mains charger to use to supplement this in case i am stationary for more than a couple of days? Can this be permanently connected to the battery? Would i be better off with another battery wired in a bank as the maximum i will be going without running the vehicle would be say 5 days? I have estimated with my usage a maximum of 3 days for the one 150ah battery without discharging it below 50%.

Many thanks for reading....