Thread: Home made 12v powerpack- Thumper

Our Discovery must have a slight earth leak & loses about .1v a day, so 10 days not getting used is a problem.The easy solution would have been a battery isolator, but no, I have to do it the hard way, so I made a Jump start pack as it was cheaper than buying one.
This is the finished unit.



It has 2x ciggy plugs, a hella plug, a battery charge indicator & jump leads via an Anderson plug.

It charges up whilst travelling via the cigarette plug in the car to the ciggy plug in the unit.
I joined two ciggy leads together so it can go in the boot or back of the vehicle



I bought a 32 amp battery off Ebay for $96.00 and cut the interiors out of a ryobi toolbox.
Looking at the inside during assembly.




I bought a Jaycar battery tester for $15.00 and used the internals. I drilled out the box using the casing as a template & poked the LED's thru. I also bought a waterproof switch for $5.00









This is it charging up - the 4 LEDS light up.

Some internal wiring, the black box on the jumper leads is a spike protector.



The all up cost came to around $180, less than half the cost of an equivalent off the shelf.
I had my doubts it would start a dead flat V8 but the thumper ads say the 30 amp unit will start a 5 litre Deisel, so i figured the AGL batteries put out more oomph.
How does it perform?? No bloody good . It barely turns over the V8 when the main battery is disconnected, it might be a good boost, but I wanted better..

So...... MARK 2






Not to be out done I bought another battery and a $27.00 tool case from Bunnings & basically swapped everything over. It has room for a 300w Inverter I had and weighs in at 29kilo's. I had to strengthen the case but it does the job no problem .

Originally Posted by jason7001

Neat box of tricks DeeJay

Benifit of being portable I can see
But:

For $303.00 ($180 for Mark 1 plus $27 for case and $96 for 2nd Battery) why couldn't you just fit a second battery ($100 - $150) with a Solenoid kit ($40 Supercheap) and have a fully charged battery to jump off anytime, not to mention couple up additional accessories to should the mood take you?

Be interested in hearing the reasons you went the Box'o'Tricks route

Cheers
Jason

It took long enough to explain to my missus how to connect up one end of the jumper leads
The Disco was probably an excuse to get it past her.
I already have 3x 100 amp batteries in my Landie, so it should be fine without any more batteries.

As I see it this, will be handy for the following.

Primarily to power my CPAP as I have sleep apnoea. ( 100 amp runs it 2.5 nights)
Run lights when I'm away from the vehicle - not too far though.
My daughter is in the scouts & I sometimes get invited along to camps but vehicles are not allowed at some of the campsites.
I go away once a year in my boat for 3-4 nights on the Gippsland lakes & take a battery out of the 4wd and jury rig up to the boat battery etc. I wont have to do that anymore.
I dont fully trust solenoids, I've had dual battery setups in 5-6 vehicles and have had failures. In the current (no pun intended) Landie I have the spare spare battery on a marine switch & a LED readout.

And finally as its totally seperate from the vehicle I can handle an alternator failure for example.


Big Guy,

Give me a thumper and live happily ever after.

I like the simple things.


Well this IS a projects forum.

I like to fiddle in the garage - I dont watch much TV
And I cant justify the $598 for a 60amp thumper, so there's 295 reasons