Thread: 18v powertool battery to start quad

Hiya all

Looking for some input on an Idea I have been mulling over.
I have a yamaha kodiak 450 that I use for hunting infrequently, because it doesn't get used much the battery always goes flat between uses.
It is an auto so no crash starting, it has a pull start but it's a pain to use, very high compression.
I have been jump starting it off a makita 18v battery and a couple of bits of wire, which works although it's a pain to lift up the seat, sketchy holding wires etc. The other thing I think that's going on is some kind of voltage leak as when I use it at night the lights start to get dim and flicker.

So I had been thinking of making a more permanent set up using the battery connection of an old powertool to hold the battery, run a couple of decent wires off it to the battery leads on the quad, and mount it all securely where the battery normally goes, the idea being that I have lots of makita batteries so can just swap them out as needed and carry a spare one under the seat too.

Just thinking about the electrical side of it, wonder whether I need to put in a resistor or some other way of stepping down the voltage from 18v-12v or just not worry about it.
Also if I need to put in a diode so the bike isn't trying to charge the battery as I know the makita batteries have all sorts of clever electronics in there. (Possiblity that the generator on the bike isn't working anyway)

The whole plan here is to have a bike that I don't need to keep buying new batteries for as they seem to drain beyond recharge levels, and use batteries that I already have so I can just plug them in and away I go.

I've seen there are a few electronic geniuses on here so hopefully you can throw in your 2c.

Cheers