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Engine vibration effect on LiOn?

Old 08-25-2007, 10:10 PM
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3d-aholic
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Default Engine vibration effect on LiOn?

I had a LiOn batterys go out after about 9 flights and 2 charges. One of the cells in a 2 cell pack...just gave up. Fortunately, I was on the ground.

This battery was mounted with foam all the way around in the engine box.

Has anybody had any negative experience with LiOn's being affected by engine vibration? Not saying that vibration is what killed the batterys but I'm pre-supposing its one possibility.
Old 08-25-2007, 10:30 PM
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Default RE: Engine vibration effect on LiOn?

Vibration effects Lithions the same way it effects any other battery. Too much is bad, mostly for the wire connections. Sounds more like you had a bad cell or left the switch turned on. If you're using a Reliaswitch unplg the batteries when they will be stored for more than a day or so.
Old 08-25-2007, 10:44 PM
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Default RE: Engine vibration effect on LiOn?

The voltage never went below 8 volts on the pack and I never charged it above 8.38 and never more than about 1/4 C. Its easy to remember since I only charged it twice besides the initial charge.

I took the battery apart and the weld joints were still good although on the cell that died it looked like the welder was on there for a long time.
Old 08-26-2007, 12:54 AM
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Default RE: Engine vibration effect on LiOn?

It is good to check the real capacity of the battery because there isn't other way to say if the chemical-constelation inside is OK,
i.e. charge it properly and discharge it over a resistor which pemiots like 100-200 mA current, i.e for about 8V that would be
like 50-100 ohms, what ever you have available and plug the mA-metter in series time to time so you can see how much is
the current. If you do not 80% of the written on the pack capacity, then some cell or both are permanently damaged, isn't it.
Those "inteligent" chargers, checkers, cell-ballancers etc. are some time a bit "stupid".
Old 08-26-2007, 07:32 AM
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Default RE: Engine vibration effect on LiOn?

The battery is gone...already exchanged. Trying to make sure of preventing anything in the future. And, the battery failed, nothing to do with the charger or anything else....I'm 100% sure of that.
Old 08-26-2007, 09:18 AM
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Default RE: Engine vibration effect on LiOn?

In fact still there isn't better choice than NiCd for any RC where the weight is not so critical.
Old 08-26-2007, 11:14 AM
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Default RE: Engine vibration effect on LiOn?


ORIGINAL: NikolayTT

In fact still there isn't better choice than NiCd for any RC where the weight is not so critical.
Yeh...too late.

I already got a couple dollars invested in the LiOn. I'm using NiMH on the ignition though. No problems with the ignition.
Old 08-26-2007, 11:34 AM
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Default RE: Engine vibration effect on LiOn?

Three(3) "escape" scenarios:

1. Make Lights to your Gas plane with LEDs; there are many versions on eBay, just type LED
and you will see such which distribute light almost in 180 deg hemisphere and you can fly
much nicer in cloudy days; when the Smoke is not visible enough - lights make lot of fun
and LiIon are nicely light-weight.

2. You can still make some Electric RC planc with those LiPoly, there they seems the best one.
In fact that might be better because you can save(!) a great deal of money if you do not crash
your gas plane due to battery falure, while an electric park flyer or el.glider is lot of fun where
there are size or noise restrictions.

3. Alternatively, there might be some lot more expensive solutions, coming from companies
which make those Multuiple-Servo Controllers. In some of them I have seen Battery
Care-Taker Unit, EXACTLY very good for taking care for LiPoly, and I hope the better device
would be the one where you plug the cells individually, i.e. inside that device should be built a
Cell Monitor. I am afraid though such unit due to limited market is going to be too expensive.
Unfortunately, I do not keep refence what the maker name was but I believe those who fly
either Giant-scale or Jets they use them whole the time, i.e. you can see their models.

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