rod replied:

All you need is a Hella 4650 type switch (approx $30.00) plus you cabling (12mm dia stuff) and connections. It will NEVER EVER wear out or fail.

rod replied:

All you need is a Hella 4650 type switch (approx $30.00) plus you cabling (12mm dia stuff) and connections. It will NEVER EVER wear out or fail.

David replied:

Hi A. Stephens dual battery systems dont always have to be expensive, if you are handy and know a little bit about electronics (not a lot, just a bit) then maybe a DIY kit is the answer.
I bought a dual battery kit from JAYCAR electronics about 18 months ago for about $50.00, it took me about 3 hours to build & about 1/2 an hour to install in my GQ Patrol, i then added an electric solanoid so i could link my main & auxillary batteries together if i was using my winch, the solinoid cost about $20.00, the most expensive item was the second battery at about $120.00, the battery frame i made up out of some scrap angle i had lying around, the whole setup cost around $200.00 including battery cable.
The JAYCAR kit automatically charges the main battery first then switches over to charge the auxillary then constantly switches between the two when need be, the both batteries are monitored from a panel inside the cab, a system similar to this when i was looking around at the 4wd stores was going to cost anywhere from $450.00 upwards not including battery, if you would like to know anything else about this you can contact me at www.workin4u.com/atrekcamping, hope ive helped, David.

Tony replied:

Hi, I use a Pirahna 150 amp system because it promised to do what I wanted (and so far it has). It all depends on what you want a dual battery system to do. For myself, I wanted to be able to run a fridge and 12 volt lights and keep the main battery totally isolated so I could not possibably have a flat starting battery when Im in the Cape or Simpson Dessert. My winch runs off the main battery but I always have the engine running when winching. Ive fitted the biggest batteries that will fit in the space available. If for some reason the batteries need to be in parrallel, I can always run a large amp jumper lead across, but the need has never arisen. Remember, "you get what you pay for" is usually pretty spot on. Cheers

mark C replied:

I have to agree with Tony. You get what you pay for. We run 4wd tag alongs and cant afford to have a failure of your vehicles heart - the electrical system. We installed a dual system using very expensive batteries ($400 each). They are both a cold cranking and deep cycle battery in one unit that will accept high rates of charge.
To date ive had no problems with the system and its always ready to go.
Just consider what the hassle/expense you are up for if in a remote area when your electronic system fails and you will get the best available. .

Jude replied:

I agree with the first guy, we have had a simple cheap system for at leats five years and the same system on our old vehicle for 3 years prior. The simple use of turning the switch is easy and with no electronics it is easy to override if necessary(not that we have had to)
I think the main thing is to get the right battery and make sure it is a deep cycle battery for for your second one as they are suitable for running fridges, lights etc. We had a deep cycle battery for 4 years and only got rid of it as it was 4 years old.

Nigel replied:

I bought the Rotronics independant isolator (approx $400) as it charges each battery seperately (which results in a quicker charge). It also allows me greater choice of batteries, as the two batteries dont need to be similar type/size as they are never joined together for charging. Choice of system will ultimately depend on your needs - I didnt like the idea of a manual system coz I would probably forget to flick the switch.

Rob replied:

The Hella Voltage Dependent Relay offers a relatively inexpensive way of automatically managing 2 batteries.
http://www.hellamarine.com/pdf/Produktfolderndversion-neu.pdf