If you like power models, you'll love this

If you like power models, you'll love this

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Discussion

Red V8

Original Poster:

873 posts

227 months

Tuesday 30th June 2009
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SlipStream77

2,153 posts

191 months

Wednesday 1st July 2009
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22.2 volts of raw power?

Last time I checked, power was measured in Watts.

Holst

2,468 posts

221 months

Wednesday 1st July 2009
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SlipStream77 said:
22.2 volts of raw power?

Last time I checked, power was measured in Watts.
Most electric motors will spin faster if you apply more voltage.
These trucks will probably draw around 100amps peak. So the total power with these cells will be 2.2kw or almost 3hp.

Im not sure how many cells these trucks usually use, probably four so fitting six cells will give a decent power increase.
Larger helicopters use six, eight or even twelve cells (thats 50V).

It looks like quite good fun but I think you would break something pretty quickly.

Roop

6,012 posts

284 months

Saturday 4th July 2009
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How boring is that bloke...? Slux is a great truck. Unusable performance unless you have acres of space, but amazing all the same.

Stickers

1,387 posts

199 months

Monday 6th July 2009
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Holst said:
Im not sure how many cells these trucks usually use, probably four so fitting six cells will give a decent power increase.
Larger helicopters use six, eight or even twelve cells (thats 50V).
It will all depend on how many are in series/parallel & as it uses Lipo's, 12 cells would give 44.4v, even @ 6 cells (22.2v) 6A, the truck will have plenty of power to tap into.

Volts = Power (think current/running water) Amps = distance/time per hour (think amount of fuel in tank) Watts = V x A (home appliances maximum is 3.120 KW).

I've been running Lipo's in RC A/C for over 7 years & the 'RC car' guys have struggled to make the change from Ni-Cad/NiMH amidst fears of 'exploding' batteries & scary tales of fires while charging.

Power is supplied to the Spitfire below via 11.1V 6000mA 12cells 3S4P Li-Po (x3 in series - x4 in parallel) & that equates to 3.7v x3 = 11.1 & 1500mAh x4 = 6A.........I use two of these batteries in parallel to give me more air time, so I'm actually getting 12A @ 11.1v.



mattmoxon

5,026 posts

218 months

Saturday 11th July 2009
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That's mental - though I prefer being able to gun it and not flip the truck over. As cool as that is, I think I'd rather run the packs in parallel and double the running time. As far as things breaking on that - maybe, I have never had a drive train failure on my Savage 25, aside from a fried clutch and a stripped spur gear/slipper clutch. They are very resilient in general, I have had it land nose in from a 6' jump bounce end over end with no damage (other than a few scuffs) at all.

Matt

Holst

2,468 posts

221 months

Saturday 11th July 2009
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Stickers said:
I've been running Lipo's in RC A/C for over 7 years & the 'RC car' guys have struggled to make the change from Ni-Cad/NiMH amidst fears of 'exploding' batteries & scary tales of fires while charging.
The problem with the RC car guys is that they are racing to a set of rules.

If you want more power in your plane then you just fit a bigger motor or more cells.

If your limited to two cells in your car then there is the temptation to overcharge the cells to get some extra power.
With NIMH cells you could overcharge them by quite a margin and get some extra power (at the expense of cell life)
When they tried the same with LiPo the cells exploded.

Stickers

1,387 posts

199 months

Sunday 12th July 2009
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Holst said:
The problem with the RC car guys is that they are racing to a set of rules.

If you want more power in your plane then you just fit a bigger motor or more cells.

If your limited to two cells in your car then there is the temptation to overcharge the cells to get some extra power.
With NIMH cells you could overcharge them by quite a margin and get some extra power (at the expense of cell life)
When they tried the same with LiPo the cells exploded.
That should stop the Buggers cheating thumbup

Roop

6,012 posts

284 months

Sunday 12th July 2009
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Stickers said:
Holst said:
The problem with the RC car guys is that they are racing to a set of rules.

If you want more power in your plane then you just fit a bigger motor or more cells.

If your limited to two cells in your car then there is the temptation to overcharge the cells to get some extra power.
With NIMH cells you could overcharge them by quite a margin and get some extra power (at the expense of cell life)
When they tried the same with LiPo the cells exploded.
That should stop the Buggers cheating thumbup
Hrm, not quite true. The problem was that of impact resistance. NiMH and NiCd cells break out on impact in a crash and can even rupture, generally there is no safety issue though. With LiPo it as a different issue. The r/c car boys have had to wait for LiPos in a nice solid case before they were allowed to be raced safely. Especially so given a lot of racing these days is indoor. The problem was that although LiPos had the capacity they didn't have the current rating until recently that would satisfy car use. 3200 cells with 25C is about the minimum you'd want in a TOCA running a modified motor. The current has to be delievered from 2 cells the same size as a 6-cell NiMH stick. Tough ask until 2 yrs or so ago...

HereBeMonsters

14,180 posts

182 months

Sunday 12th July 2009
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I've seen lots of NiMHs explode, but never a LiPo. Catching fire and slowly smouldering, yes. Especially funny when running in a mate's car with a classic Alfa shell.
"They all do that mate, nothing to worry about..."

vdubbin

2,165 posts

197 months

Monday 13th July 2009
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HereBeMonsters said:
"They all do that mate, nothing to worry about..."


Thanks for genuine Monday morning LOL!