I’ve had my Rustler VXL for about a year now and have been content running it on a 7-cell 8.4v Ni-HM 4300mAh Battery Pack. With the correct gearing this was good to take the truck up to about 45mph. Well the battery has been slowly dying over the past couple of months and I was barely able to get 5 minutes runtime out of it in the end. So I decided enough was enough and bought myself a 3-cell Li-Po 11.1v 4000mAh Pack from eBay. The only trouble is, when I tried to test it out, I found the battery didn’t fit in the tray, it was slightly too long. Also, the wiring comes out the side of a Li-Po pack, not the centre, another problem needing to be solved. So here is what I did.

Tools needed

Dremel
File
Safety glasses
Steady hand
Patience

1. I used a mixture of the Dremel drill type cutting bit and a routing bit to attack the chassis with. First up I made a slot on the side of the battery tray for the connector to pass through tidily. Use your file to smooth all the burrs off the plastic, you don’t want it nipping your battery wires.

2. Next up was the toughest part, taking a hole out of the rear bulkhead. It’d be easy to just cut the entire section out, but I wanted to leave a strut across the top, not only will this help maintain chassis rigidity, it also helps hold the battery firmly in place. Take your time with this, as it is tough to get the angle of attack right. You’ll get there in the end. Again make sure to file all the burrs off after you’ve finished.

There we are, job done! The battery I was using was a fairly tight fit, if yours isn’t I recommend putting a block of foam in the hole to prevent the battery moving about. Also it’s handy to place a strip of ribbon across the tray before you fit the battery, it helps with removal.