Dual battery setup for 2.8 1GD

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

I have been following this thread closely. Having just ordered a new GX the modifications will soon start! Re. VSRs..... all anyone seems to talk about are those made by Redarc. The question is will any other brand like Ironman, ABR,Pirana , Baintec etc do the same job at [mainly] cheaper prices? Secondly should such a VSR be mounted closest to the main battery or the secondary battery. My set up will eventually have to feed a third battery in the camper. Do I need another VSR between the 2nd and third batteries to stop the charge/ discharge equalizing between them? Thanks.

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

I would think any (quality) isolator would be fine 404pug, the isolator would live as close to main battery as possible - with the exception of drivesafe's model that can live anywhere along the cable run.

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

TA. What about the need for a second VSR between batteries 2 and 3? My big user of power will be the 25 year old Engel in the car [ ie . battery2] Mainly lights in the camper.

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

I would have thought you'd simply unplug the camper from the prado and then batt #3 in the camper is isolated?

[InnerCityBoy Junior Member Find all posts View Profile Close InnerCityBoy]

My set up will eventually have to feed a third battery in the camper. Do I need another VSR between the 2nd and third batteries to stop the charge/ discharge equalizing between them? Thanks.

I would recommend doing something to isolate the camper battery from the dual battery under the bonnet. Last trip I did, my camper battery failed and drained the under-bonnet battery down while the car was sitting parked with the camper still connected.

There are any number of ways to achieve this ... a VSR would work (as you have suggested); a relay switch that is triggered by the ignition; if you install a DC charger in your camper to charge your camper battery (like a C-Tek or Redarc), they essentially have a VSR built-in; and of course simply pulling the lead out when you stop

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Hi 404pug, there is actually big advantages to leaving the house and auxiliary batteries connected.

While events like InnerCityBoy’s can occur, they are very rare.

Whereas by leaving all the batteries connected, you give your setup a number of advantages.

The obvious is that you have a larger battery capacity available, meaning you can go longer before you need to drive or charge the batteries.

But also, by spreading the load over more batteries, you lessen the current draw on each battery, and this helps to extend the operating life span of the batteries..

Even is you don’t use all the battery capacity available before you drive again, because none of your batteries were as low as they would normally have to be, you will be able to fully recharge them in a shorter drive time.

Lastly, by just leaving all the batteries connected, you simplify your setup and save money at the same time.

[sweetpea Senior Member Find all posts View Profile Close sweetpea]

Hi 404pug, there is actually big advantages to leaving the house and auxiliary batteries connected.

While events like InnerCityBoy’s can occur, they are very rare.

Whereas by leaving all the batteries connected, you give your setup a number of advantages.

The obvious is that you have a larger battery capacity available, meaning you can go longer before you need to drive or charge the batteries.

But also, by spreading the load over more batteries, you lessen the current draw on each battery, and this helps to extend the operating life span of the batteries..

Even is you don’t use all the battery capacity available before you drive again, because none of your batteries were as low as they would normally have to be, you will be able to fully recharge them in a shorter drive time.

Lastly, by just leaving all the batteries connected, you simplify your setup and save money at the same time.

The house battery in my camper does very little; it runs the LED lights, power for the pressure water pump and charging for the tablet and kindle.

When I travel remotely I use a VSR to isolate the starting battery to ensure I can start.

The auxiliary battery is for safety and powers the HF radio and is therefore isolated by another relay from the camper.

The camper battery is for everything else which, as stated above, is almost insignificant.

We travel quite lightly and don't have an electric winch, a microwave oven or a plasma TV and we leave the nesspresso machine at home.

For our needs, it is just easier to isolate all the batteries when the alternator stops. It doesn't suit everyone.

YMMV

S.

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

Thank you all. I have time to digest as I am told my new car is 8 weeks away!

[Jimbo! Lurker Find all posts View Profile Close Jimbo!]

Hi Guys
Ive followed this thread, but am still not sure there was agreement on the best way forward for a duel bat system for the 2.8L.
I have one (a 2.8L) now, and want to install the second battery in the next couple weeks. Primarily to run a 50L fridge in the back, and leave my caravan connected during short stops so the van fridge keeps power.
Has anyone heard any developments on the best solution?

[Lski Member Find all posts View Profile Close Lski]

Hi Guys
Ive followed this thread, but am still not sure there was agreement on the best way forward for a duel bat system for the 2.8L.
I have one (a 2.8L) now, and want to install the second battery in the next couple weeks. Primarily to run a 50L fridge in the back, and leave my caravan connected during short stops so the van fridge keeps power.
Has anyone heard any developments on the best solution?

Jimbo, I went with the isolator in my 2.8 and wrote a brief report here (4/4) which may assist you...
http://www.pradopoint.com/showthread...Moreton-Island

[InnerCityBoy Junior Member Find all posts View Profile Close InnerCityBoy]

Jimbo - you won't find agreement on this forum - some swear by DC chargers as the best way to fully charge a dual battery (whether under-bonnet or in a camper trailer), others claim (correctly from what I can tell) that they're slower than directly charging from an alternator charging, especially during the bulk charge phase for a battery that is heavily discharged.

For what it's worth I charge my under-bonnet dual battery direct from the alternator (through an isolator) and find it works well. I have a DC charger in my camper trailer to charge the camper battery which also works well. I don't, however, have any hard numbers on how quickly the batteries get charged.

Personally I would charge your under-bonnet battery direct from the alternator and see if it charges the battery suitably for your needs. You can choose to add a DC charger later if needed.

[Jimbo! Lurker Find all posts View Profile Close Jimbo!]

Thanks Lski, that report was great.

[swh2959 Lurker Find all posts View Profile Close swh2959]

Excellent thread. Thanks. I am going to simply use my Pirhana DBE 150S dual management system I took out of the 3.0L and put it in my new 2.8L. I have a very similar set up to InnerCityBoy but simply disconnect car and camper trailer when parked up [electrically anyway]. This set up has worked well for years for me. I do have panels for when parked up for any length of time.
What I can't find is an ignition switched power source on the drivers side rear engine bay. I have searched the forum to no avail. The green wire to the wiper motor I have read about seems to be constant 12v. Please advise.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

The green wire in the pre updates at least is definitely acc switched. I use it to trigger my compressor. Surprised if it is constant 12V.

[swh2959 Lurker Find all posts View Profile Close swh2959]

The green wire in the pre updates at least is definitely acc switched. I use it to trigger my compressor. Surprised if it is constant 12V.

Well after your post I thought I better check again - so I did - and on my vehicle the green wire to the wiper motor is constant 12v. In fact I checked all 5 wires going to the wiper motor and none are ignition switched power sources.