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-   -   12v starter Lipo battery? (http://www.rcuniverse.com/forum/batteries-chargers-84/10926640-12v-starter-lipo-battery.html)

skypiratescotty 01-25-2012 06:10 AM

12v starter Lipo battery?
 
Hi There
Just curious, i want to make my 12v starter for nitro planes portable by strapping a Lipo battery to it. Is this a bad idea? I'm looking at Lipo packs and not sure what mah or "c" rating will work. Thinking 4s (14.8v) and around 3000mah 20c. I know the voltage is high but i figure short 5-7 second burtsts for engine starting would be OK. Anyone tried this or have any ideas?

Thanks
Scotty

Goldenduff 01-25-2012 06:58 AM

RE: 12v starter Lipo battery?
 
Yes, I do this and it is fantastic! I use an 11.1v lipo but my biggest glow is .55. Works fantastic- my lead battery took up half the space of my starter box and didnt maintain a charge.

Max amp output is (mah x C) /1000. So your lipo could provide 60amps. Not a problem but you could use a cheaper (lower C rating and or lower mah capacity) and probably a 3cell lipo too. But if you have the 4cell lying about I don't see a problem with it.

I disconnect the lipo and store it away from my starter box because of their volatile nature, my starter box looks too much like a bomb already with the fuel bottle, tubes and wires- no need to add a lipo in there too!!!!

p.s.I actually connect my lipo to the power panel to power glow driver as well but you could make a very portable starter by connecting it directly.

vicman 01-25-2012 09:33 AM

RE: 12v starter Lipo battery?
 
I use a 4s 4400 mah lipo for mine and love it!
You want to do like GB and unplug it between flying days as there is a small amount of drain. If left long enough you could over draw your batteries and mess them up. Otherwise it's one of the best things I've done in a while.

richrd 01-25-2012 09:44 AM

RE: 12v starter Lipo battery?
 
+1
I use 3 cell 2100mH 20C works better than the motorcycle battery ever did
BTW check often for over discharge, but mine lasted for weeks then just charge to 80%
rich

Goldenduff 01-25-2012 10:19 AM

RE: 12v starter Lipo battery?
 
80% is a storage charge? If flying a lot go the full 100%!!Agreed , best thing I've done for a while too!

richrd 01-25-2012 11:17 AM

RE: 12v starter Lipo battery?
 

Quote:

ORIGINAL: Goldenduff

80% is a storage charge? If flying a lot go the full 100%!!Agreed , best thing I've done for a while too!

YEA splitting hairs, but if not flying soon after charge may get puffing etc etc... 3.9V is the number i shoot for an recharge at 3.5V still only do couple times a summer
iam a little on the safe side :-) but my batteries are 4 years old so it seems to work for me
riich

Goldenduff 01-25-2012 01:14 PM

RE: 12v starter Lipo battery?
 
Didn't mean to split hairs- just didn't want to get the wrong end of the stick

skypiratescotty 01-25-2012 01:48 PM

RE: 12v starter Lipo battery?
 
Awesome!!!! Thanks for all the input. I'm still thinkin 14.8v 20c anything from 2000-4200mah as I want some crankin power. Most of my engines are .46- .76 but when I hit the 1.00 and 1.20 2-strokes I don't even want to consider the starter might not turn them. Actually, all my engines will flip start but gettin em primed is a pain so a strong starter will really help. Plus, this is just a side project for me to tinker with and have something not many if any of the folks at the field have.

Thanks again
Scotty

drumduan 01-25-2012 02:00 PM

RE: 12v starter Lipo battery?
 
hey scotty, the brilliance is the simplicity- 5mins tinkering time and you will have a more portable, more powerful, more compact, more reliable etc etc starter!

Not sure what the amp draw on a starter is but if you need to replace the lipo I think you could get a cheaper lower C and or mah one.

Party on,

vicman 01-25-2012 07:02 PM

RE: 12v starter Lipo battery?
 
Most of my flying is with Jetts and Nelsons and I have no problem kicking them over.

Now how bout a lipo glo igniter[8D]
I charge mine 3 times a year.

Goldenduff 01-25-2012 11:30 PM

RE: 12v starter Lipo battery?
 
My lipo powers a power panel subsequently powering my glow igniter.<div>
</div><div>You would need a form of voltage regulator if connecting directly?</div>

Mikecam 01-31-2012 11:08 PM

RE: 12v starter Lipo battery?
 
1 Attachment(s)
I use 2 of these on my cheap hobbico 90 starter. Most of the starters you can run up to 24 volts for the extra cranking power. My setup fully charged is about 22 volts. Using a bigger battery with the same volts will not get you extra torque but it will last longer.
I laughed one time when a fellow flyer flooded his DLE 30 and I brought out my starter to turn it over and he said no way. I said lets try and guess what it turned it over. :D

http://www.hobbyking.com/hobbyking/s...ter_pack_.html

http://www.hobbyking.com/hobbyking/s...dProduct=10264 One of these to put the battery's in series.

They work fine even at 2C but get a little warm on the gassers. I would use some 3S life higher C rated battery's next time. Leave them fully charged for months and no worries.

When/If my Deluxe torqmaster 90 goes up in smoke I'll get a sullivan, they are rated to 24 volts. I also kept the wire and panel banana plugs and added an xt60 connector so if I run my life's down I can still pull out the panel ready wire and start that way.

http://www.hobbyking.com/hobbyking/s...ePo4_Pack.html These would be perfect, would fit nice into the starter handle as well.

Goldenduff 01-31-2012 11:47 PM

RE: 12v starter Lipo battery?
 
Larger capacity enables higher amp draw (capacityx C = max amps) so it does give extra cranking power?

skypiratescotty 02-01-2012 04:58 AM

RE: 12v starter Lipo battery?
 
1 Attachment(s)
Hi All
OK, so this is what I came up with. I found a NIB vintage Royal Heavy Duty starter for $20. With leads on I hooked it to my 12v Lb battery and it would barely turn my GMS .76, but once I connected it to a 3000mah 14.8v 20c Lipo it will easily crank my Magnum 120 2-stoke. It'll start my buddies YS 170 4-stroke easily too. I have no doubt that this would really give a ton of extra punch to any 12v starter, in fact I'm gonna connect it to my cheapy Tower Hobbies starter just for sh*ts and giggles. I know the battery is a little much but it was on sale for $22 so for under $50 I have a starter that will turn anything as big as I plan on flying.

Scotty

The_Shark 02-01-2012 07:36 AM

RE: 12v starter Lipo battery?
 
so cool, i was just going to post this question. i have a 1500mah 30C 3s pack that i want to use for a bump box, the battery looks too small, but i think it will work just fine.

richrd 02-01-2012 09:59 AM

RE: 12v starter Lipo battery?
 

Quote:

ORIGINAL: skypiratescotty

Hi All
OK, so this is what I came up with. I found a NIB vintage Royal Heavy Duty starter for $20. With leads on I hooked it to my 12v Lb battery and it would barely turn my GMS .76, but once I connected it to a 3000mah 14.8v 20c Lipo it will easily crank my Magnum 120 2-stoke. It'll start my buddies YS 170 4-stroke easily too. I have no doubt that this would really give a ton of extra punch to any 12v starter, in fact I'm gonna connect it to my cheapy Tower Hobbies starter just for sh*ts and giggles. I know the battery is a little much but it was on sale for $22 so for under $50 I have a starter that will turn anything as big as I plan on flying.

Scotty

is that a hard pack ???
just a FYI i made a hard case so the battery does,nt get all dented because if a dent gets to a soft pack strange things may happen "fire is one problem"
rich

skypiratescotty 02-01-2012 11:54 AM

RE: 12v starter Lipo battery?
 
hey Shark, i don't know what a bump box is but 3s is 11.1v and charged prolly close to what, 13? 3s should be good for any 12v application but i just needed more and the starter can handle it for short bursts. i mean, i don,t run a starter more than 4-5 seconds at a time.

rich, preciate the advice on the case. i just slapped this together to see how it would work and for right now am just very careful when i handle it and set it down. i do plan on making something real nice with aircraft plywood i have lying around to give a new starter an old skool look.

scotty

Mikecam 02-02-2012 06:07 AM

RE: 12v starter Lipo battery?
 

Quote:

ORIGINAL: Goldenduff

Larger capacity enables higher amp draw (capacityx C = max amps) so it does give extra cranking power?

Go try it on your starter, hook it up to your truck battery and tell me if it suddenly turns over gassers.

drumduan 02-02-2012 06:50 AM

RE: 12v starter Lipo battery?
 
Very sadly I do not have a gasser!

I put a question  mark after the "statement" because you can't hear inflections in text, it was a question not a statement so I wasn't saying it would work.

"I use 2 of these on my cheap hobbico 90 starter. Most of the starters you can run up to 24 volts for the extra cranking power. My setup fully charged is about 22 volts. Using a bigger <font color="#000000">battery</font> with the same volts will not get you extra torque but it will last longer"

A "bigger" battery with the same volts can give more power. I have an 11.1v 2000mah lipo rated at 20C, so it can give me 11.1v x(2000mah x 20) = 444watts. If I use an 11.1v 3000mah lipo rated at 20C I can get 666watts out of my power system. That's 30% more power with the same voltage but an increase in the available amps. I appreciate when using a starter to use these amps you may need to change the gearing rather than simply changing a prop but it still stands that you can get more power from a bigger battery with the same volts.

skypiratescotty 02-02-2012 07:04 AM

RE: 12v starter Lipo battery?
 
i don't crunch numbers or even really care to but results are what pulls my britches up. when i connected the Royal starter to a 12v lawn tractor battery or the battery in my F-150 it still was WEAK but once i connected it to a 14.8v 3000mah 20c Lipo it easily cranks a Magnum 120 2-stroke. i've got a Sullivan Dynatron and a 22.1v 3000mah 30c Lipo on the way and I can guarandangTee ya it's gonna crank up something or twist my arm off trying!! LOL

Scotty

drumduan 02-02-2012 07:18 AM

RE: 12v starter Lipo battery?
 
I do tend to agree (results being what matters, not the maths) however....

The lawnmower battery (?Pb) will drop its voltage under load a lot more than the lipo so that could account some of the difference.

Also a bigger battery can give more power- splitting hairs I know but it is important sometimes (you can smoke a smaller mah lipo of the same C rating than a higher mah lipo because the higher mah can deliver more amps).

richrd 02-02-2012 09:12 AM

RE: 12v starter Lipo battery?
 
Do'nt forget guys when we connect up the LiPo an the starter my leads went from 2 feet w/ clips to 1 inch with deads
guessing about 2 volts loss in those long cables, more experaments but iam to lazey an it works now:D so leave it alone ha ha ha
rich

Goldenduff 02-02-2012 09:32 AM

RE: 12v starter Lipo battery?
 
Agreed!

skypiratescotty 02-02-2012 10:38 AM

RE: 12v starter Lipo battery?
 
well now, it would look pretty silly walking around draggin a Lipo 5' behind you cuz you didn't cut the leads!!! very true though, the shorter the lead, the more DC power there is.

dirtybird 02-02-2012 01:11 PM

RE: 12v starter Lipo battery?
 
I have a Miller persuader mounted on a standard 12V Sullivan starter.
I use 8 A123 batteries on it for 24 volts. It starts my G-62 with gusto, I bet I could start a small Honda with it.
BTW I have used 4 A123 batteries to start my motor home when the MH battery was dead.
With A123's you don't have to worry about:
Fire
Storage charge
Over discharge
Storage temperature
Time discharge


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