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Use 2 cell lipoly with no regulator???

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Old 01-08-2006, 02:12 PM
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WRK
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Default Use 2 cell lipoly with no regulator???

Wondering if you can use a 2 cell lithium poly battery pack for a plane with out using a regulator?

Thinking about it, the voltage would not be much higher than a freshly charged 5 cell Nicad battery pack which is used with no regulator so in that case the radio system is seeing close to 7.5 volts at first before the battery voltage starts to come down.
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Old 01-08-2006, 11:20 PM
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Default RE: Use 2 cell lipoly with no regulator???

my l packs start out at 8.31 volts. i am running a reg on this end i need to help kept the companies in business
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Old 01-09-2006, 10:09 AM
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Default RE: Use 2 cell lipoly with no regulator???

I saw a post from Bax (the Futaba guy) on this question and IIRC he said it's the servos which have more of a problem with the higher voltage.

He didn't recommend it.

I'm just putting together my first model with Li-Ion packs so I don't have any experience to answer your question, but from all my research on the question, I'll be using regulators on both the rx/servo and engine ignition batteries. Even though the new ignition modules for the engine I'm using say the higher voltage is okay, and it is a two cell pack, I think the proven method is the way I'll go on this one. I've got way too much $$$ in this model to risk it for the price of regulators...
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Old 01-10-2006, 05:59 PM
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Default RE: Use 2 cell lipoly with no regulator???

I tried a Hitec 5955 on 7.4V. It lasted about 3 minutes before it toasted the amplifier. I was putting a steady load on it. You might be able to get away with it in an airplane since the load would be intermitent. I wouldn't try it.
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Old 01-10-2006, 08:18 PM
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Default RE: Use 2 cell lipoly with no regulator???

dirtybird, do you think that Hitec would have fried on an unregulated, 5 cell nicad pack, that was fresh off the charger? I've seen the voltage close to seven.
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Old 01-10-2006, 08:23 PM
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Default RE: Use 2 cell lipoly with no regulator???

I don't think so. If it had a large load the voltage would quickly drop to around 6V. If it didn't have a load it would not be bothered.
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Old 01-11-2006, 05:49 PM
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Default RE: Use 2 cell lipoly with no regulator???

thanks.
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Old 02-02-2006, 06:04 PM
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Default RE: Use 2 cell lipoly with no regulator???

Can somebody list sources for regulators for receiver batteries?

Would a 3 cell lipo (11.1 volts) cause damage to a transmitter without a regulator?

Thanks.

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Old 02-02-2006, 08:23 PM
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Default RE: Use 2 cell lipoly with no regulator???

Using Li-Po's in a Tx sounds like a project for "The Handyman's Corner" where the motto is "if it ain't broke, your not trying hard enough"
Seriously, I can't imagine an advantage, but I can think of a lotta negatives.
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Old 02-02-2006, 09:44 PM
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Default RE: Use 2 cell lipoly with no regulator???

Coop02,
I have been using JACCIO regulators in my jets for the last (4) years or so. You can get them in a couple of different voltages- I have used both 5.1 and 5.7 volts. Available from Central Hobbies in Billings,MT.406-259-9004. The last ones I bought were $29.95 each.
Good Luck,
Al Watson
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Old 02-02-2006, 11:01 PM
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Default RE: Use 2 cell lipoly with no regulator???

PilotPete2: Well, the one big advantage is being able to put a huge capacity battery in the transmitter which will operate it for many hours (or days) without recharge. A Lithium Ion battery would probably be safer than LIPO, but I have been using lipos in electrics and never had a problem.

AlW: Thanks for the info. I'll check it out.
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Old 02-03-2006, 07:51 AM
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Default RE: Use 2 cell lipoly with no regulator???

go to radicalrc.com and get a 2300mAh Tx battery pack... fly for DAYS without charging....
agree with the above post... putting LiIon in a TX just is more of a hassle then it is worth when I can get a 2300mAh battery for MUCH less and just plug it in......

as for regulators...

I use MPI regulators...no problems.... may switch to Fromeco sometime soon...
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