Thread: Dual battery system

I believe a DBS would go under the passenger seat or in the rear cargo area

My 2nd battery is in the back. It has DC-DC charger built in. Very neat. Wired to a main battery feed underneath.

Now I have to go and check both those positions..... just something else to think about. But what went in that hole under the back floor cover originally?
AlanH.

Have put battery plus charger under floor in back. Easily removable to access 48v system

Hi Alan, you need to do a fair bit of research before you commit to a specific type of dual battery system in your new Defender.

If you only want to run a fridge and are not concerned about any form of backup for your cranking battery, then a DC/DC + Lithium battery setup will meet your needs.

BUT, the short operating span of the cranking battery in the new Defenders is proving a problem, where their cranking battery can go flat in as little as a week if the new Defender is not driven regularly and unless you use a more expensive Drop-In type lithium battery, this is something a standard lithium auxiliary battery setup is of no use for.

I am working on a new Dual Battery setup for the new Defender, which will be specifically purposed to help maintain the cranking battery for much longer periods on non use time but still be used for running a fridge and other basic accessories.

My new Dual Battery System for the new Defender is some time away yet.

The fundamental question is what type of battery will suit your power requirements. Lithium batteries have changed the game. They come in all manner of shapes sizes and capacities. They can be put in all sorts of places a conventional battery can't. (In the engine bay isn't one of them due to heat). So start from what your needs for power and work forward to the solution.

At least for the moment, I'm eschewing a fixed dual battery system and opting for a lithium power station that can be topped up from the accessory socket in the rear when driving and solar panels when conditions are right when we are stationary. If push comes to shove I can get a powered camping site and charge it from a 240v mains power supply.

When travelling we rarely stay in one place for more than two nights and drive a minimum of 4 hours a day when we move. The 35 litre fridge is all we need to power when camping.

As an aside, I've found the stowage capacity of the new one not much less than my old Defender. I have had to rethink what I carry and how it is stowed but all I need can be carried including a large swag inside and not on the roof!

As advised always start with what you need the power for - how much and how long for. Then how much charging capacity you need to replenish your use and design from there.
For just a fridge and a couple of lights then keep it simple.
I want to replace gas cooking with induction so intend to put in 200Ah of battery with a 250A BMS and inverter.
Charging will be DCDC - we rarely base camp at present and some solar down the track.
There's plenty of examples of setups on the New Defender AU FB group. Worth joining as you do your research.