New to electric:need battery/ gearing help

[pro4]

I was wondering if you guys could tell me all about the terms and stuff of batteries and gearing.

First what are volts, amps, discharge rate, etc.?

How many amps should I charge my battery at?

What gearing would you use on a lehner 5200 with uforce75?

What are the basics of gearing?

Thanks for the help

[elecracr]

Each cell of a battery is 1.2 volts, adding up to 7.2volts for a six cell battery pack. In order for me to tell you what charge rate i need to know what battery you have. You only need to discharge your batteries if they are Nicad. Pretty much with gearing, the higher pinion, the gear that goes on the motor... the higher it is, the hotter and faster your motor will run. But if you gear lower, you get more torque and lower temps. The opposite applies with your spur gear.
We will also need to know what car and setup you are running to tell you about gearing, if i were you just make an edjucated guess then check for heat in the motor and esc very frequently untill you all get a reliable setup.

[pro4]

I'm going to run a gp3300 6 cell pack(can you fit 7 cells on a pro4 while keeping the extra cell on the same side of car? It doesn't look like it will fit?) Anyways the packs are on ebay and there is a 1.17s and a 1.18s? What's the difference?

1.18s- http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=34063&item=5952707249&rd=1

1.17- http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5948424027&ssPageName=STRK:MEWA:IT

[pro4]

As for gearing I was told by my lhs. 98t 64p spur and start with a 25t pinion and go up until you like what you see.

[ElectricThunder]

The lehner motor has gobs of torque, so at that gearing it should be just fine. You can probably gear a lehner with an FDR of like, 7:1 or something and still have some torque on tap. Just start small on the pinion and increase till you find what you like.

[pro4]

Uh, I can't read that. Can you change language?

[elecracr]

As for the batteries, im not sure if a 7cell will fit... But i do know that 1.18 volts will be a slightly better pack than the 1.17. This means that the 1.18 one will be .06volts better for the whole pack, only the most experienced racer will notce a big difference with that. The best thing you can do to improve your lap times is to practice your driving skills, you have plenty of power, but the question is can you make it around the track without wrecking while using that power?

[pro4]

What is the discharge rate? Do I always need to discharge my battery, how far should I run it down?

I got a reedy quasar charger. How many amps should I charge my pack at?

Thanks

[murphy3688]

you shouldnt have to discharge since theyre nimh. just put it back in the charger and go. if you were to discharge, 20-30 amps is an average discharge rate, down to .9v per cell (5.4v for a 6 cell pack).

lower amp charge (such as 3 amps) will decrease "punch" but increase runtime, higher amp (such as 5 amps) will give you more "punch" but you might lose some runtime. 4 to 5 amps is a good starting point (at least i think so). good luck

[evaderstracr]

what is the difference in run time of 3 amps to 4?

[pro4]

Do I run my battery completely out of juice, or what? Thanks for all the help

[murphy3688]

you prolly wouldnt notice a difference in runtime between 3 and 4 amps. i dont. its more likely youll notice a difference in "punch" rather than runtime. namely, between 3 and 5, youll feel more power. its hard to count runtime in your head, so you might not even notice it. many "pro" racers charge the gp3300s at 5 amps.

pro4- no, never let batteries discharge past 5.4v for a 6 cell pack. but since you own nimh cells, you will never have to discharge. when you want more juice, just put it back on the charger to peak and youre ready. many say discharging it once a month (or every three or four races) is a good guideline for nimh.

[ITurnLeft]

I EQ my cells weekly, charge @ 6A and I don't believe in blind discharging. Blind discharging is when you look at the total pack voltage and stop discharging when it reaches 5.4v (as suggested earlier in this thread.) The logic behind it assumes all the cells are equally charged. In a perfect world, that's correct. Sadly, cells discharge at different rates and become imbalanced. An EQ tray restores that balance and gives you 6 equally powerful cells. If you are just starting out, this isn't a major deal because bouncing off the wall one time during a race will negate any advantage a few extra millivolts is going to give you. But, once you are to the level where you need every last bit of power from your packs, you'll care greatly about these things.

As for your gearing.. You should be able to hold your finger on the motor for 4-5 seconds without having the agonizing pain force you to remove it and cry. So put on a pinion, run a few laps and check the motor. Too hot? Drop a tooth. Ice cold? Run a few more and check again. If it's still cool, go up a tooth and repeat. Keep in mind also that your tire size is going to dictate your gearing. Taller tires need smaller pinions, and shorter tires need larger pinions.

[pro4]

Since I don't have a charger with any sorta screen on it, how can I tell the voltage? But while running my batts. how far should I run them down? Thanks for all the help for the electric dummy

[murphy3688]

a good stopping point would be when your car starts to slow down to the speed you can walk. BUT IF YOU HAVE NIMH, just peak it back and store it.

[ITurnLeft]

"BUT IF YOU HAVE NIMH, just peak it back and store it."

AFTER the pack has cooled. Never charge a pack while it is still warm from a previous run.