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lipo's and starters

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Old 05-18-2014, 09:20 AM
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Stick 40
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Default lipo's and starters

I have read some of the info on using lipo's for our elect plane starter. There was a statement of drawing to many amp's from a lipo and damaging it.

I have a new Sullivan 12/24 starter and want to use a lipo for the larger engines. One guy said the way to find out how many amps a lipo will put out is to multiply the "C" output say 35C times the rated cap. of the lipo. Like 35 times 5300 or 35X5.3 = 185.5 amps. Is that right.

next question how many Amps would the starter draw on a 1.2 saito ?

thanks

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Old 05-18-2014, 09:50 AM
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I use an ancient 3 cell 2200mAh lipo to turn my starter on engines up to .60 size. I haven't tried it on anything larger. Several guys at my home field are using similar setups. It all started when my field box battery died and I couldn't use my starter, tried it and it turned an engine right over. I getting ready to order a new 4 cell 2200mAh for my starter. The amp draw is minimal so I'm planning on buying the cheapest I can find.
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Old 05-18-2014, 01:22 PM
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I use two 3 cell lipo batteries for my Little giant 6-1 gear reduced starter. It will start up to a 170cc engine and only needs recharged every couple months. I have never even had a battery get warm.
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Old 05-18-2014, 02:09 PM
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I'm running a Dynatron starter off a pair of 7.4V 5000 mah 30C lipos hooked up in series for a total of 14.8V. No issues but I only spin up my engines for a few seconds at a time. If you have an engine that does not start fairly quickly, figure out the issue and fix it rather then continuing to spin it up with the starter.
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Old 05-18-2014, 03:11 PM
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I use a 3 cell lipo on my starter. Probably 2200 mah or so ( cannot remember ) . Very short leads as the battery is attached to the started with velcro. Starts Saito 150's 4 stroke and 40cc gassers. Charge every 2 months.

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Old 05-18-2014, 05:09 PM
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Stick 40
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thanks for the input,

The other question was is my way of figuring how many amps you can draw from a lipo

I have two 3cell 5300 Mah amp lipos that are rated for C35 discharge. one person said to multiply 35x 5300 Mah or 35x5.3 amps for a max draw of 185.5 amps. .

I would think that , if that is right I can use the lipo's with out worrying about them.
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Old 05-19-2014, 05:34 AM
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Total hogwash. C ratings on lipo batteries really don't mean much. They are useful sometimes for comparing batteries within a manufacturer for high performance applications, but that's it. Honestly, you aren't going to be able to pull enough amps with a starter to worry about it. If you notice that your batteries are getting hot when you use your starter (you won't) then that's an indicator that you're asking too much of them. But there are an awful lot of a guys using 3 cell 3000 mah lipos on starters with no issues at all.
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Old 05-19-2014, 07:03 AM
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A good alternative to standard Lipos for a starter battery is A123 batteries. Been using them for years with a couple Dynatron starters, one has a Miller reduction and the other standard. Big plus is that they can be left fully charged, no need to put them in a storage charge state, and they can be almost fully discharged without damage.

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Old 05-19-2014, 08:37 AM
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I use a 3 cell 1800, starts my ys120 no problem
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Old 05-19-2014, 05:41 PM
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this is where I am at now. I have two 3 cell 5300 Lipo's.

thanks

Last edited by Stick 40; 05-19-2014 at 05:45 PM.
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Old 05-19-2014, 05:46 PM
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good point, I am using them for onboard RX's now and like them. May look into this.

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