Took my beater 1/8 XRAY 4x4 buggy to a field near home. I never noticed it behind the small neighborhood government center before so I wasn't familiar with it. Great place. I brought the dog so she could get some exercise. R/C is great for luring. Anyway, the site has a huge crater-like depression 120+ feet across at the bottom. Probably 15 - 20 feet deep and a 50 degree incline all around to jump in and out of. A huge open field surrounds the crater and the surface is cut grass. Easily big enough for high speeds. I didn't think to scout around the crater. About 5 minutes of blasting around, I launched off the opposite rim. Next thing I saw after the buggy descended out of sight was a splash.
Instantly I knew it was a death sentence. Electronics are: a hefty Tekin T8 Gen3 motor with RX8 Gen3 ESC, Futaba CB700 HPS servo and R334SBS S/R receiver. Also, a 6S SMC 5200mAh battery and a cheap LiPO alarm. Everything is exposed in the build except a small receiver box.
The buggy was upside down and completely under water with only one rear tire just breaking the surface. I pulled it out, disconnected the battery and went home. 10 minutes later I was blasting every millimeter of every part (battery too) with compressed air. I blew out every droplet of water I could see from every crevice and connector. Then I propped it up with everything still intact and installed. I then hit it (including the battery - removed but next to the car) with hot air from a heat gun about 18 inches away such that everything was hot to touch but not uncomfortable. I left it like that for 2 hours to assist in evaporation.
After everything cooled down I put a fresh battery (same brand and spec) in it and turned it on. It ran perfectly - 100%. I put in on some blocks and ran it with enough RPM to slightly grow the tires and let it run like that for 30 minutes - to dry the foam. Yes, plenty of run time unloaded. I took the submerged battery, now dry and cool, and gave a gentle 2C charge to full capacity. Cell resistance was 2.5 - 0.8 milli ohms across all 6 cells. Just like when new and like the other battery of same (almost new) age. 5 days later I measured the cell voltage and they only dropped a couple of thousandths of a volt each - impressive. No swelling of the pack and no heat with discharge. I thought about replacing the battery at least - lithium and water is probably a bad combination. But, there is zero evidence of any problems with the pack. I haven't removed the shrink wrap covering, so ultimately, who knows...
I expect to be servicing some related issues sometime in the future (suspension, diffs...) and maybe replacing an electronic, but for now I have a clean buggy that seems no worse for the mishap.
Cheers.
Instantly I knew it was a death sentence. Electronics are: a hefty Tekin T8 Gen3 motor with RX8 Gen3 ESC, Futaba CB700 HPS servo and R334SBS S/R receiver. Also, a 6S SMC 5200mAh battery and a cheap LiPO alarm. Everything is exposed in the build except a small receiver box.
The buggy was upside down and completely under water with only one rear tire just breaking the surface. I pulled it out, disconnected the battery and went home. 10 minutes later I was blasting every millimeter of every part (battery too) with compressed air. I blew out every droplet of water I could see from every crevice and connector. Then I propped it up with everything still intact and installed. I then hit it (including the battery - removed but next to the car) with hot air from a heat gun about 18 inches away such that everything was hot to touch but not uncomfortable. I left it like that for 2 hours to assist in evaporation.
After everything cooled down I put a fresh battery (same brand and spec) in it and turned it on. It ran perfectly - 100%. I put in on some blocks and ran it with enough RPM to slightly grow the tires and let it run like that for 30 minutes - to dry the foam. Yes, plenty of run time unloaded. I took the submerged battery, now dry and cool, and gave a gentle 2C charge to full capacity. Cell resistance was 2.5 - 0.8 milli ohms across all 6 cells. Just like when new and like the other battery of same (almost new) age. 5 days later I measured the cell voltage and they only dropped a couple of thousandths of a volt each - impressive. No swelling of the pack and no heat with discharge. I thought about replacing the battery at least - lithium and water is probably a bad combination. But, there is zero evidence of any problems with the pack. I haven't removed the shrink wrap covering, so ultimately, who knows...
I expect to be servicing some related issues sometime in the future (suspension, diffs...) and maybe replacing an electronic, but for now I have a clean buggy that seems no worse for the mishap.
Cheers.