Battery power for camping

[madcampbell]

I spent two weeks camping in cornwall and used the back of the surf as a dumping ground for all the stuff we did'nt want to be kicking round the tent.
However using the back window all the time took its toll on the battery. We didn't drive anywhere one day but still used the back of the car via the rear window. The following day the battery only just had enough power to start with a struggle.
Questions....
If I fitted another battery could one be used just to start the truck and the other be switched on while the engine was not running.
On a yatch they have a dial that allows you to use the one battery just for running the lights and bits at night then you switch to the other for starting.
Can it be done??and how? what do you do? how does the charging all work?
I only have a single battery
Cheers
Mark

[codlord]

Questions....
If I fitted another battery could one be used just to start the truck and the other be switched on while the engine was not running.
On a yatch they have a dial that allows you to use the one battery just for running the lights and bits at night then you switch to the other for starting.
Can it be done??and how? what do you do? how does the charging all work?
I only have a single battery

There are a number of ways you can implement 2 batteries, but probably the easiest is what I intend to do soon (I got exactly the same issues you have), have two (decent) batteries and an isolator switch, so you can isolate one battery while camped up, then you will only be drawing power off one battery. When you want to start you un-isolate the battery and have both batteries available for starting.

See here for the sort of switches you will need (including the marine dial one you talk about which allows you to have one, both or none) but I will just be installing a normal on/off switch for one battery I think.
http://www.vehicle-wiring-products.c.../battisol.html

Obviously if you only have one battery now you will have to install another first. See here for some basic info on installing a second battery, although this was from my old surf where I tried to install a dedicated leisure battery:
http://www.showmesome.info/hilux/workshop/battery.htm

Basically you will just need to connect your 2nd battery earth to the chassis and the two batteries positive to positive with your isolator switch inbetween. with proper high-amp battery cables though (all cables and connectors can be bought from the same place as above):
http://www.vehicle-wiring-products.c...N/BATTCON.html
http://www.vehicle-wiring-products.c...es/cables.html

[madcampbell]

There are a number of ways you can implement 2 batteries, but probably the easiest is what I intend to do soon (I got exactly the same issues you have), have two (decent) batteries and an isolator switch, so you can isolate one battery while camped up, then you will only be drawing power off one battery. When you want to start you un-isolate the battery and have both batteries available for starting.

See here for the sort of switches you will need (including the marine dial one you talk about which allows you to have one, both or none) but I will just be installing a normal on/off switch for one battery I think.
http://www.vehicle-wiring-products.c.../battisol.html

Obviously if you only have one battery now you will have to install another first. See here for some basic info on installing a second battery, although this was from my old surf where I tried to install a dedicated leisure battery:
http://www.showmesome.info/hilux/workshop/battery.htm

Basically you will just need to connect your 2nd battery earth to the chassis and the two batteries positive to positive with your isolator switch inbetween. with proper high-amp battery cables though (all cables and connectors can be bought from the same place as above):
http://www.vehicle-wiring-products.c...N/BATTCON.html
http://www.vehicle-wiring-products.c...es/cables.html

Thanks for that very helpfull answer
Cheers Mate
Mark

[SeanH]

I think I should warn you though, if you drain only one battery that gets charged as a twin, ie what you guys are saying, then the battery that doesn't get 'flattened', will end up getting overcharged by the alternator causing the plates to buckle.

I'm not just ranting, it's happened to me, quite an expensive mistake!

May I suggest using a twin battery set-up like mine has as standard, it'll take a lot more use to flatten both of those!

[codlord]

May I suggest using a twin battery set-up like mine has as standard, it'll take a lot more use to flatten both of those!

What do you mean by "a twin battery set-up like mine has" - can you elaborate.

Thanks

[TJG]

Mine came with two batteries too, it runs 2 80amp/hr batteries. If you managed to drain the battery in a weekend and you wern't using it to power a fridge or havy duty lights I would suspect the battery and get a new one.

[codlord]

Mine came with two batteries too, it runs 2 80amp/hr batteries. If you managed to drain the battery in a weekend and you wern't using it to power a fridge or havy duty lights I would suspect the battery and get a new one.

I have 2 batteries, not sure what spec (but they don't look particularly meaty) - I was running an electronic coolbox for more than 24hrs, a 12v strip light for quite a while and the back window up and down a fair bit - that was enough to make a non-starter though.

[TJG]

Fridges kill batteries, that is why on towbars the circuit to power up the 12v for the fridge in a caravan is dead until the engine is running.

If I want to use a 12v coolbox I take one of those jumpstart pack things with me, that will last about 12 hrs, so I don't run the fridge at night and it just about strugggle through the weekend, working on the assumption that by the last day you have scoffed all the food and the last few hours it will just keep cold by residual. Also get a mains adapter and run it for a day or so before you go to make sure it is nice & cold to start with.

My 12v outlet doesn't work without the ignition on, so if you do use the car socket make sure fans etc are all turned off.

[Newboy]

I think I should warn you though, if you drain only one battery that gets charged as a twin, ie what you guys are saying, then the battery that doesn't get 'flattened', will end up getting overcharged by the alternator causing the plates to buckle.

I'm not just ranting, it's happened to me, quite an expensive mistake!

May I suggest using a twin battery set-up like mine has as standard, it'll take a lot more use to flatten both of those!

In a boat if you have a 2 batteries set up, a device is fitted (can't remember the name) so that the engine will only charge the battery that needs charging. Otherwise the good battery will act as a greedy ba*tard keeps asking for more and the crap battery won't get charged at all.

[Grimreeper]

In a boat if you have a 2 batteries set up, a device is fitted (can't remember the name) so that the engine will only charge the battery that needs charging. Otherwise the good battery will act as a greedy ba*tard keeps asking for more and the crap battery won't get charged at all.

Think what your looking 4 is a split charge unit.....it only chages the 1 thats flat.
On models with twin batteries they are only low amp batts connected as 1.....if you ant to use 1 for starting and one for camping stuff then you should replace 1 with a higher ampage batt for starting and the other use for leisure through the split charger. then no matter how flat the leisure batt gets you will always have 1 2 start from the when the starter batt is fully charged it will switch and charge the flat 1. Thinking of doing it with mine when it comes to needing new batts.

[mrkeeg]

I think I should warn you though, if you drain only one battery that gets charged as a twin, ie what you guys are saying, then the battery that doesn't get 'flattened', will end up getting overcharged by the alternator causing the plates to buckle.

I'm not just ranting, it's happened to me, quite an expensive mistake!

May I suggest using a twin battery set-up like mine has as standard, it'll take a lot more use to flatten both of those!

So will this bad happen in a system like that described here?

http://www.showmesome.info/hilux/workshop/battery.htm

... since the 2 batteries are linked during charging?

Thanks
Keegan

[AndyLala]

The problem comes with a simple relay connected dual battery system.

The flat battery and the 'full' battery are connected together, when the ignition switches on... (engine not started yet)...

Full battery dumps its contents into the flat battery until they have an equal amount each... you now have two half charged batteries.

You could set the relay to switch when the engine starts running or trip the switch line on teh big relay with a timer relay... but that gets rather messy.

I have done the following and for the moment, it will suffice. These are supposed to run the starter alone until the engine is started, or there is sufficient in the pair of batteries to crank the engine. I installed the base model DBi from the following people.

http://www.ibs-tech.ch/

They also do some rather natty solar panels that with a regulated feed trickle charge your 'leisure' battery, and provide enough to run a 'camp' light and the fridge. I use a red top as the starter, and an Exide Maxxima as my leisure unit. I am investigating whether the http://www.ibs-tech.ch/lbp_e.html low battery protection circuit will give any major benefit, when running the fridge...

If you want to really go for it...
These guys do some real big jobbies for serious use with the engine not running, tail lifts, eberspacher/webasto, etc...

http://www.adverc.co.uk

But that is real expensive. You will need you alternator modded, and some serious storage capacity.

[mud-ge]

just a thought ,but would it not be simpler to carry a truck battery or high out put car battery use this all weekend then take it home to charge with a trickle charger ,with this option you could always add a solar charger from some one like towsure and be able to top up through out the day

[MattF]

just a thought ,but would it not be simpler to carry a truck battery or high out put car battery use this all weekend then take it home to charge with a trickle charger ,with this option you could always add a solar charger from some one like towsure and be able to top up through out the day

Personally, I would use a split charge setup with a third battery,
separate from the main batteries. Screwing up the starting
ability of the beast is bound to happen at some point. I stick to
the motto of a part for every purpose.

[mrkeeg]

Thanks for the info Andy.

I don't really need to get into the advanced stuff.

If I understand you then, the problem only arises between when you turn the key to start the ignition, and when the truck is actually running - in that time, the main battery is significantly drawn down by the auxillary (even if I'm only using 10gauge wire between them?)

I suppose none of the current circuits are already designed to only be on when the truck is actually running (vs with the ignition on but not started, as you say is the danger) - otherwise I could run the switch off of that.

I spose I could have a manual switch in the cab, no relay at all, and just flick it on to connect the batteries for charging while I drive?

Hmm...

Keegan