Wednesday 2 March 2016

Secondary Battery System for Camping Trip

So, I've done a few research into 4WD battery system (dual battery system) since I had few colleagues asking me what secondary battery system is best for their 4WD camping-bush-trip. The more I look into this (in Australian market), the more I am impressed of how expensive these battery systems are. By simply looking into REDARC website, one should wonder, why on earth battery management system can cost in the order of thousand of Australian dollars (excluding batteries). There is nothing 'smart' with lead acid batteries! Boy oh boy!!

It is true that you need some charging management system so that your car is protected from over-loading in charging deep-cycle batteries. But, do you really need to spend thousand dollars computerised battery charging system?

"People don't buy for logical reasons. They buy for emotional reasons" rings so true in this 4WD market. Just looking around the car park at my work, people spent literally tens thousands of dollars to upgrade their 4WD (or cars, generally). Nothing wrong with that of course, here is me being hypocritical, willing to spend hundreds of bucks accumulating second-hand batteries to satisfy my emotional needs! Luckily I can't afford those yet.

Anyhoo, for those who want to go camping trip, and simply need pure battery function (no emotion involved), then I got a surprise for you! Please don't buy those off-the-shelf power pack (the like of ArkPak) with batteries from camping shop, they are a RIP-OFF!! If you can tinker a bit, then you can save literally hundreds of dollars!!! (yup, that's right, 3 exclamation marks)

Here is my proposal (no need to tinker your car wiring either):


Component list:

  1. Cigarette Lighter 12V plug from Altronics (click here)
  2. DC – DC converter (to be set to 13.8 Volt and 5 Amp). Get it here.
  3. 12V 100Ah lithium battery
  4. Low voltage protection switch
  5. 12V cigarette lighter socket


Technical note:

  • The setup above is charging the lithium battery one way only, i.e. no current back flow from lithium to your car system.
  • Since you plug it to your car's cigarette lighter socket, it ONLY charges when you turn the engine on. Do keep it connected all the time to ensure the battery charged, always.


The whole lot above can give you up to 1000Wh of electricity and cost less than AUD1000. Forget those expensive ArkPak or the like that can cost you more than double of what I proposed above. Well, yes, you do need to tinker a bit, but hey, I'm talking to those who are adventerous right? The electric is so simple: red to positive, black to negative. Come on, it's not rocket surgery (or brain science)!

If you feeling even more adventerous, you can replace the supply (item 1 and 2) with solar panel (minimum 60 Watt) with MPPT module. For the MPPT, I can recommend Genasun. Please, please, please, simply skip crap 'charge controllers' and save yourself troubles.

Happy camping!