Twin battery set up.

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Hi all! After last weekend I realise I need to get a 2nd battery attached for auxillary use i.e. for my powerful lamp for night time shooting. Anyone give me some ideas what I need to do, also what size/type of battery etc. Any suggestions/advise greatly appreciated.
Cheers, Nige. Wink

Mmmmm

Put them in parallel if you think the alternator can cope!

Disagree. Firstly, it depen

Disagree.
Firstly, it depends on what vehicle we are talking about here. Fourtrak/Rocky or Sportrak/Feroza. The former has plenty of room for a second battery, the latter less so.
I have twin N70 size batteries in my Rocky, charging through a simple split system set up. This keeps the primary battery fully charged, while allowing the second battery to become discharged if need be.
If you connect both batteries in parallel, its possible to flatten both.

Cheers
David

Growing old is compulsary, growing up isnt, and MUD MAKES EXCELLENT TOOTHPASTE.
Please visit http://groups.msn.com/AussieDaihatsuRocky/_whatsnew.msnw
All views and advice offered are my own, from my own experiences. Take such advice at your own risk.

Growing old is compulsary, growing up isnt.
MUD MAKES EXCELLENT TOOTHPASTE.
I use billion dollar satellites, to find Tupperware.
Please visit http://groups.msn.com/AussieDaihatsuRocky/_whatsnew.msnw
All views and advice offered are my own, from my ow

Forgot to mention

Forgot to mention it's a Fourtrak. What are N70 size? Currently (pardon the pun!) it has a 72A battery fitted. I can get a larger tray fabricated no problem but I would like to know how it should be wired up correctly. Sounds like you suggest in series. I intend then fitting a 2nd cigar lighter socket for my lamp.

Cheers, Nig.

Sorry Nige Terminology los

Sorry Nige

Terminology loss due to different countries. N70 is a popular large size of battery here in Oz.
http://groups.msn.com/AussieDaihatsuRocky/davidsrocky.msnw?action=ShowPhoto&PhotoID=64

http://groups.msn.com/AussieDaihatsuRocky/davidsrocky.msnw?action=ShowPhoto&PhotoID=281

These two pics show the dual battery tray in mine. In the second, you can see the continuous duty solenoid on the left, which controls the charge of the second battery.

Dont hook the batteries up in series. You will have 24 volts, and do serious damage to your vehicle. My opinion, you need some sort of isolating system which charges both when engine running, but isolates the second battery when not running.

Cheers
David

Growing old is compulsary, growing up isnt, and MUD MAKES EXCELLENT TOOTHPASTE.
Please visit http://groups.msn.com/AussieDaihatsuRocky/_whatsnew.msnw
All views and advice offered are my own, from my own experiences. Take such advice at your own risk.

Growing old is compulsary, growing up isnt.
MUD MAKES EXCELLENT TOOTHPASTE.
I use billion dollar satellites, to find Tupperware.
Please visit http://groups.msn.com/AussieDaihatsuRocky/_whatsnew.msnw
All views and advice offered are my own, from my ow

i suggest you look at a split

i suggest you look at a split charge relay as used to charge caravan batteries . this allows the 2nd battery to be charged from the vehicle alternator, it doesnt allow things powered from the 2nd battery (normally the interior fittings in the caravan) to draw current from the main vehicle battery, or provide any power from the 2nd battery to the starter motor. the lights powered from the 2nd battery cannot then flatten the starting battery, and the wiring is done with normal "thin" vehicle wiring. in this case the 2nd battery does not have to be the same capacity as the main vehicle battery, it can be any old car battery or even a 12v leisure battery.

the other alternative is to wire a 2nd identically sized battery in parrellel (positive to positive and neg to neg) with the first using the thick battery/ starter type cable, this effectivly gives a double sized battery, the disadvantage being if u power lights without the engine running u will still eventually flatten both batteries.

this caravan split charge syt

this caravan split charge sytem is the way im thinking of going with mine,
5 pairs of spotlights on the front,
and a spotlight on the rear acting as a worklight,
copled with a serious sound install (1,200w r.m.s)
all put huge drain on the battery,

although the caravan type split charge wont start the forutrak directly,
i have thought about adding 2 battery cut-off switches and hardwiring the second battery in useing battery lead wires,

1 switch would cut the feed from battery one,
while switch 2 would then kick in battery 2

this way i would never be without power,

well that the thought anyway

appreciate some feedback before i do it,
again im capable of doing the schematics and wiring,
and if theres other members think this may work,
i'll give it a go,

and if its successful
post up a schematic
which may assist others

Like the sound of this

Thanks for your suggestion, this is what I need to do I believe. When I get it done I shall post some pictures. Cheers, Nige.

Get an automatic isolating so

Get an automatic isolating solenoid like David has in his rig.

This way your starting battery cannot go flat!! This is why you are putting in a twin battery system.. so you can still start your car at the end of the day!

Wiring in parallel still allows the starting battery to go flat.. and if one of the batteries has an issue or they are not the exact same models, one will drain power from the other.. hence losing all charge.

You can buy kits to hook it all up that includes the solenoid which allows the secondary battery to be charged at the same time as the main battery by monitoring the voltages of each battery.
It also isolates the main battery from going flat when using accessories because you hook all your extras to the secondary battery.