Batteries/gearing/run time

[knucklebuster]

I posted this in another dialogue and don't want it to get lost. OK, I'm just anxious for some input.

I ran stock a few times as a teenager. I really didn't experiment much with gearing. When I became interested in RCs again I began adjusting gear ratios almost every run to turn the 6 gear. If any of you run these, press on.

I continue to use Tekin chargers. My original works like new, one I picked up with the $35 RC10 false-peaked until I shortened the output leads to decrease resistance. I purchased 1500 NiCds (I'm CHEAP) and began playing with "toys" again.

I assumed NiMH were the norm for racers and only provided a little more juice and 1-2 minutes extra run time (+/- 500-900mAh). In general, what are run times for 2400NiMH batteries with mild modified motor/gearing? I'm not looking for your coveted gear ratios for the track, just some ideas. Basically, if I throw in another chunk of change for a charger and 6+ batteries am I gonna have sooooo much more fun and run time?

[qctires]

In general, what are run times for 2400NiMH batteries with mild modified motor/gearing? I'm not looking for your coveted gear ratios for the track, just some ideas. Basically, if I throw in another chunk of change for a charger and 6+ batteries am I gonna have sooooo much more fun and run time?

Track time is five minutes with optimum gearing to mfinish and maybe leave some juice for another 2 laps or so. For bashing, (not on trace track) with a re-cycled set of 2400s, and lower gear ratio, maybe 7 minutes. It depends on how many winds you are using and your ESCs capability. That is also running with no drag brake. Just my 2 cents.

[Eau Rouge]

Honestly, the original NiCd batteries from the 1200-2000mah rate were geared to last 4-minute races (or 8-minutes for 12th scale). In modified, most of the time, they geared to dump just after the finish line with no mistakes, and no more runtime. The fast guys developed "bump boxes" with parallel battery packs to "jump" the cars on the start line to give a little more punch for the race. Back then, you NEVER ran the car even a foot before the race, because you needed all of the runtime you had in the pack.

Today, with current 3800-4300mah NimH batteries, you can run for eons more than the old packs. Hell, they make AA transmitter batteries now with more aH of time in them than the old SC Sanyos.

BUT, each car's runtime is determined by many factors in your car, including: rear tire diameter, friction in the drivetrain, motor brushes and springs, comm trueness, armature balance, and most importantly, how much throttle you are using through the pack. An oval will use more amps than a road course or a dirt off road track, and running at full speed up and down the driveway is completely different than racing on a track.

Also, how good are you packs? Are they matched? Were they good to begin with? How were they maintained and taken care of? Were they discharged properly before storing? You could potentially cut the run life of an old NiCd in half by improper care and/or storage.


What I'm getting at is that it's almost impossible to gauge with a stopwatch how long any pack of batteries will last in any given car. Every factor that makes these cars run determines, to some degree, how long the car will run and how fast it will be.




But, yes, the new NimH batteries make the old NiCd packs we used to use look like the R/C dark ages. They are THAT much better. I can run a 12th scale stock motor for over 13 minutes on one charge, when 15 years ago, I could barely get to 7 minutes before a major performance loss.

[badhoopty]

i'm glad someone who has alot more experience than i posted that nimh's are way better than nicd.

i dont run my buggies much, but i recal 20 or so years ago the batteries sucked and maybe lasted 5 minutes. nowadays with nimh i never feel severely dissapointed with runtime like back in those days.

on my crawlers i can get 30+ minutes runtime on a charge with nimh cells.

[justinspeed79]

I remember my first NIMH experience. I put a Team Orion Team-Matched pack in my B2 and was blown away. Since I have been using NIMH bats there has actually been times when I stopped running the car before the batteries dumped.

[knucklebuster]

I run Novak T4s and and a Futaba 112 escs. With stock-mild 16T and final drive ratio around 9 I get around 8 minutes run time. The futaba runs hot with a 16T (thanks Carloco). I'm tryline to determine a baseline for what I have. The T4s are ready for hotter runs (I think). I won't cry on this board if there's a meltdown.

I discharge 1500 NiCd non-matched Panasonic batteries out of the bag, peak charge with 15+ year old chargers and want more run time. My runners are all 6 gear with full bearings with the exception of the one trany with bushings (aargh). Mabye after all these years I'll actually get a STEALTH! Based on your responses, I"m in for a few dollars more.

BTW I just finished painting a used body for the $35 RC10. I had to paint white due residual paint after stripping yellow paint with blue taped stripes. I put one decal (STEALTH) on the body. That pan will needs some drilling, a new trany and a new name. It's not a $35 RC10 anymore!