Project Slash – LiPO and spring preload changes

The next step in the Slash project was to add a LiPO battery into the mix. The XL5 ESC is compatible with 7 cell NiMH batteries, or up to 2S LiPO batteries. The switch over is trivial: turn it on, then press and hold the power button for about 12 seconds and it will switch from red to green. This enables the low voltage cutoff (or LVC). Without the LVC, the LiPO battery can discharge too much, and that can ruin it (as in, it will no longer hold a charge), or even catastrophic failure (as in a fire – if you google “lipo fire” you will find some scary videos).

Then I dropped it (the car) on the ground, and pulled the trigger. Wow, it is a lot more lively with a LiPO battery than with the NiMH battery. It really came alive. Even with the stock brushed motor, it was a lot peppier than with the NiMH battery.

I also timed it. From the first rip of the trigger, until the LVC cut in, I got 22 minutes, 45 seconds. Or about three times as long of driving than with the NiMH battery.

Additionally, the car was a LOT more fun with the better battery. Alas, it put a pretty big grin on my face. The car became more responsive, snappy even. It was an eye opening experience.

I also put in the large spring preload collets in the front shocks. I was driving at a wide open parking lot, and the manual recommended the adding of collets for hard, high-traction surfaces. It made a big difference in the handling.

Probably the best 22 minutes of my week!

Next up, I am going to do some work on the shocks. The common thread is that they need the aluminum optional shock caps. The Traxxas “Ultra” shocks – the ones that come stock on the base Slash, have plastic bodies, and plastic caps. Even minor bashes into hard things (like curbs or rocks) tend to pop the plastic caps off, so the recommendation is to keep the plastic shock bodies, but to upgrade to the optional caps. I will also take this time to change the shock fluid from the stock 30 wt to 50 wt (I have 70 wt for the rear) that should help firm up the front.

Tomorrow, I will charge it up again, and let ‘r rip. I will also bring out my Losi Super Baja Rey to extend my run time.

So far, I am totally grooving on the Slash. More than I expected. Plenty more upgrades planned.

(sorry, these posts are out of order. This SHOULD have been posted a few weeks ago)

Product Manager in Tech. Guitar player. Bicycle Rider. Dog rescuer. Techie.