Second battery

[Deleted Member]

With all the gadgets that i have in my truck and for future projects,i was thinking of putting another battery in the T2 with a split relay to charge it and a small fuse board to run all the gadgets.
How easy is it to fit another battery and split relay or would it just be easier to get my local auto electrician to do it??
I have another battery!

 

[CHASTER]

Hi Steve.
Starting with the last part of your post ; it's always easier to call in the experts ; downside is that they usually need payment :roll: No job satisfaction there either.
Seems that maybe what you are seeking is increased CAPACITY as a larger reservoir to back up your extras when you are drawing more current than the alternator can produce. Good scheme; especially if you already have a (decent)spare 12 volt battery available.
Can't see why you should need a split charge relay. When you connect the two batteries in parallel (pos to pos / neg to neg) the alternator will just see them as one ( albeit, bigger) battery and divide its output charge between them as needed to bring them both up to equal and optimum voltage.No problem there so long as both batteries are in good condition.

I would be hard pushed to find space under my bonnet to site an additional battery. Perhaps you are luckier
If you need to site the battery remotely from the original battery it is ESSENTIAL that the cables used are auto grade,copper, as short as practical and as large a cross-section area as possible. A bit if consolation here though; you are really only concerned about the positive cable. No NEED to install a seperate negative all the way back so long as the negative side is well and truly earthed at both ends with short thick straps or cables to substantial chassis or body parts which give a negligable resistance electrical path back to the negative side of the original battery.
Another point to remember about remotely sited lead acid batteries; they need ventilation--hydrogen----bang----say no more !
Adding an additional fuseboard is really useful when you have a shedload of extras. At least you can readily go to it for isolation /repair purposes. Having said this; you must know what you are doing when it comes to cable and fuse sizes. 8)
Hope the above makes sense and helps.
Good luck if you take the plunge Steve. :wink:

 

[(RIP) PLANK]

I have done this on a couple of tranists to operate beacons radio etc wen the vehicle is standing still. I used a smartcom auto swith relay and a leisure battery for the second battery as it meant i could listen to the radio run work lights etc and still start the van to go!

If you join the two batteries together + to + and - to -, as chaster rightly said it will work fine, but you could still flatten both batteries when the vehilce is using power via accesories, and the batteries dont have to be a matching pair!

with the relay option you can also use the second battery as a 'swap' for you caravan battery when you are away from mains. and even use it to jump start you other battery should it ever fail!

It may also be a less troublesome option if you are concerned about the wiringin side of things!

 

[Deleted Member S]

Hi Cosmic, I would mout the second batery on the N/S in front of the air box & I think some Mistrals have one there :roll: I would also fit a split charge to save the main battery for start up & as Plank has said you can always jump start yourself if the main battery ever go's flat.

 

[Deleted Member]

Thanks all for the informitive replies,i think infront of the air intake is really the only place that another battery could go.
Will have to get a mounting plate weilded to put the battery on,i prefer the idea of a split relay so that both batteries are independant of each other.
I'm sure i seen somebody on the forum with a mistral with twin batteries,or anybody that has twin batteries to see how it all works..
Excellent advice as usual,thanx again!! :lol:

 

[Deleted Member S]

Hi Cosmic there is an old Patrol in the breakers down the road from me so if you want I could have a look to see if it's still got the battery trays in it :smile:

 

[Deleted Member]

That would be great m8!i'm going for this now,next project if you like :lol: :lol:

 

[(RIP) PLANK]

further to sweety's comments that is what i have dione on transits the battery tray bolts diwn and a petrol vans battery is on the oposite side to a diesel, so eith a petrol battery tray you are half wy there!

I dont htink its this straiht forward for a T2 and i dont have one here to check but most cars sem to have all sorts of threaded holes that go unused so maybe you can take advantage of them for a battery mounting!

if you llready have an auxilliary (grey topped) socket on your tow bar, the wiring for a seconf battery should allready be there!

 

[jims-terrano]

I've been looking into this for some time now and the split charge system is def the way to go for me. My biggest obstacle is the battery tray, need to fabricate one for the near side. I am lead to understand that the alternator has a connection that is live when the engine is running, not just when the ignition is on.
I have a 20' aerial mast to go one the side of the truck and need to run a radio in repeater mode which means it does twice as much transmitting and will run the car battery down easily.

Let me know how you get on Cosmic

Jim T

 

[Deleted Member]

if you llready have an auxilliary (grey topped) socket on your tow bar, the wiring for a seconf battery should allready be there!

Does the wiring go up into the engine bay!! think this would be the easiest option being that i have the grey plug and don't use it for the caravan as everything has been changed to mains...

 

[(RIP) PLANK]

generaly speaking yes it goes into the engine bay often via a relay, i dont see why you couldnt charge your second battery from this, and then run your auxuilliary socket from the second battery.