lipo pack

been looking at the idea of a lip pack and this seems the best amount of amps for a good price but im not sure whether its the amps or the c rating that your looking for to run a robot

http://www.ebay.co.uk/itm/320982959747? ... 293wt_1151

Nicd, nimh, and Lipo are fine to supply current req in fw , and hw if in parallel the most benefit of Lipo is the weight saving, and also they do kick out the amps :!:

well at the mo im using 2x 7.2v 3000mah battery in series to make 14.4v and its running 4 motors in 1 bot i think more power is required as the nimh pack can only do 30a peak probably and each motor probably uses about that when pushing something

14.4V then. That's a 4S pack, in Lipo it gives 14.8V nominal.
Even a cheap Zippy or Turnegy pack does 30C, and that means on 3000mah, it's 90A rated.

If you don't need the really high end packs, I can advice hobbyking.

Use Hobbyking for my stuff

Did manage to destroy one pack but that was my fault with a deep discharge due to sticking motors, thats roboting

i have found a 4s 2200 mah nano tech that says it can do 25c continous and 50c burst, dunno if that would do i assume the higher the c rating the mor amps it can draw in 1 burst

The C value is exactly what you write Plargen.
The times the rated amp value can be drawn from the pack . First -lower- value means you can draw that untill the low voltage limit is reached. The higher value is the amount of amps that will damage the pack if drawn longer than an instant.

so at 2200mah 25c continuous would be 55a and the 50c burst at 2200mah would put out 110a

That is correct as far as I understand the situation.

http://www.ebay.co.uk/itm/Turnigy-nano- ... 1670wt_919

this is the lipo i have been looking at

http://www.hobbyking.com/hobbyking/stor ... duct=29271

The place the other seller got it.

Price seems right.

mario you are correct in your statement about the C rating of lipo packs. Simply multiply the capacity of the battery by the C rating to determine the current it can supply.

I would always advise over sizing lipo batteries as you will damage them if you do a deep discharge.

Quote:

---

Originally Posted by terry

Nicd, nimh, and Lipo are fine to supply current req in fw , and hw if in parallel the most benefit of Lipo is the weight saving, and also they do kick out the amps :!:

---

As far as I am aware Lipos are still not allowed in a heavyweight with the exeption of one machine which is trialling them.Or have I missed an important announcement? Would like to know before I buy A123s

Yep sorry I didn't mean that Lipo was allowed in hw, I wrote it wrong ! Nipper has had em in a while now maybe they will be allowed sometime.

Still don't see any reason they aren't.......

For heavies LiFePo4 packs are allowed. LiPo ain't.

A123 is the first comemrcialy LiFePo4 battery making firm. But in the meantime, there are several factories/firms making their own batteries based on that chemistry.

And I agree with Gary. I don't see any reason to keep LiPo out of heavies.

Have a decent 14.4v LiPo pack for sale !

viewtopic.php?f=166&t=5198


Am sure we could do a deal !

60amps available for 4 drills at 14.4v is loads. We're running the same setup at 18v, and we can push all day long. It took a complete stall to burn a 15a fuse, and you won't stall when pushing (wheels will spin and prevent it). Even if all four drives stalled (not even worth thinking about likeliness-wise) you'd be pulling what your current batteries can supply.

LiPo will allow you to put more weight into armament but I don't think you'll see an improvement in power, save the little increase in volts.

If your speedos aren't holding back the current draw, which they will be if they can't transfer the amps without generating heat, check all other areas of wiring. Any connectors or solder joints or thin wires that aren't designed to do the amp carrying will hold the machine back.

14.4v well-delivered to 4 drills should put you above most machines in pushing power.

Edit: WAIT, wait, scratch that! You are running two packs in series, giving you just 30amps available, not the 60a I got into my head. Yes, you're likely not getting the full punch out of those motors if they can only have 30a. My bad, mate, we're travelling, blame it on the fumey tunnel we're currently going through!

lol :lol: i was estimating that the motors can draw about 30a each because i had a sabertooth 12a in my 2wd robot before and it cuts the power if they draw more than 25a and makes the robot judder a bit i'm guessing they would probably draw more if they stall

every robot ive seen make the jump to lipo has been improved by doing so...you will see a big increase in the acceleration of your robot more than anything,

4 Drills will run easy on a 3300mah pack 30c pack or similar and last a few fights.... the bigger the better though.

diablo runs on a 1300mah 6s pack that weighs about 150g :)

that's good to know :D , so far the 4wd robot can push scruffy round a basketball court for about 10min quite happily but it will be interesting to see the difference with the lipo's

It will make a big difference, but it will also (I hate to say it) potentially make using nylon gears impossible as they'll likely strip. Assuming you haven't gone to all metal already or intend to.

Speaking of which, does anyone have a source of the metal gears in drills? We could *cough* perhaps *cough* make use of such a source. :lol:

Edit: well then that's okay. :P

the drills i get of ebay already have metal gears so i don't :D have to worry about that lol

the gr1 gears might be compatible with most drill

http://www.gimsonrobotics.co.uk/spare-p ... _GR02.html

The gears you've linked to will fit most 36:1 drill gearboxes. There will be an two additional sizes released in the next week or so, adding the possibility for those with 36:1 drills to convert them to 24:1

just wondering if this looks like a good lipo to run 4 drill motors

http://www.ebay.co.uk/itm/Turnigy-Nano- ... 3ccb71bafe

its 154a burst

just spotted this

http://www.ebay.co.uk/itm/Turnigy-nano- ... 3a7adbc549