Fitting a second aux battery

[4ePajero]

To me this is getting WAY to complicated.

The way I see it:

• You have a battery to charge.
• You chose to charge it with a DC-DC charger, which claims it can use min. 10.5V input voltage.
• The input (charging source can be one of at least the following sources:
  1. The alternator
  2. A solar panel
  3. Another (charged) battery
• In the case of using the alternator, you have to protect the cranking battery from running flat (because it is coupled to the alternator)
• In the case of using another battery as charging source, you have to protect the charging battery from being depleted below a chosen voltage

How you achieve this with plugs and switches can be sorted out once the above is confirmed.

[SimonB]

Ok so I have all the goodies, the box is made and sitting in my garage waiting for the varnish to dry. Cost me nothing as I had a some 4 and 6mm plywood lying around (as opposed to the cheapest (and ugliest) battery box which was R200).

Still need to go collect a few Brad Harrisons from Powermite. I'm not paying more than double (R65) at Outdoor Warehouse.

Manie said he'd get back to me on a potential solution for charging direct from the first aux battery so nothing is being wired up yet. I suspect however I'll keep to the idea as per CATS's redundant setup, but we'll see.

[SimonB]

A couple of piccies. Still need to wire it all up and attach the lid.

[4ePajero]

Nice!
Why the charger outside? Heat?

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[SimonB]

Gerhard

Yeah for cooling. There's a fan in the charger and I it was to make that fan's job as easy as possible.

[SimonB]

My project is almost complete... the "system" has been on "test" for most of the day, running the fridge and the inverter charging camera batteries. I'll leave it until it flattens the battery until the low voltage cut-off kicks in.

I spent most of the afternoon re-installing the new modified battery tray (it was too small for the new DC batteries) in the engine bay and trying to run the second set of cables into the cabin. My fingers are too small and too weak for these electrical cabling jobs. But it's done and now it's a matter of sticking all the connectors on and powering it all up.

[SimonB]

Amazing how these projects always explode... Not literally however, my wiring is 100% so far.

I was never happy with how I originally wired in my radio and TPMS so I have redone these as well with their own dedicated fuse box

I am still looking for some way of drawing power only when the ignition is on for the TPMS (previously connected to aux battery). So any bright sparks for this?

[4ePajero]

Connect power supply to be connected via a solenoid, that is triggered by the ignition.

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[SimonB]

Gerhard

My problem is sourcing ignition power in the first place... I dont know where to draw the trigger from.

[4ePajero]

Back of ignition switch is usually best.

You either get the correct wire by inspection (AVO meter or test lamp) or from the wiring diagram.

You have the wiring diagrams?