Plastic magic and LiPo batteries, chargers, etc…

[Guido SambucettiParticipant @guidosambucetti90794]

Hello there,

Many years ago I transitioned into this hobby from my youth´s kit model building. I still have several unassembled kits with which I loathed to depart, somehow expecting to find one day a way of installing some form of RC in them and see them sailing as I dreamed to in bygone years…

And after reading Tony Dalton´s article on his experience in motorizing a Baby Bismarck I saw a way of finally turning my old fantasies into realities and, after a few seconds of running in circles like that cartoon bear that didn´t know what to do next, I sat down and read the article over again, with greater attention to details and my notebook at hand to find out more information on the components needed and (being a NiMh guy) several doubts sprang to my mind, as follows:

LiPo´s seem to have much more capacity than NiMh but in one post I read that someone kept them in a fire-proof bag while charging and someone else installing alarm lights for low battery in his ships. Are they really that dangerous?

What special abilities are needed when soldering battery tabs to their wire?

Will a NiMh charger suit them or do they need a specific one?

I´d really thank any advice on these, as I have the impression that LiPos mean, maybe, too big a change.

Cheerio!

[Guido SambucettiParticipant @guidosambucetti90794]

[ashley needhamParticipant @ashleyneedham69188]

Guido. LiPo batteries MUST have a Lipo charger to charge them up, or you will be needing that fireproof bag…

Lipo batteries need more care taken of them, as they can easily be ruined by over charging or over DIS-charging. If small and light is what you need, then you dont have much choice.

BUT , plastic magic conversions do not generaly need that much power, and so you can get away with smaller motors running at lesser voltages and so fewer Nimh batteries. There are plenty of small 3V motors (for instance) out there, which could be powered by 6V of AAA Nimh batteries (as you need 5v normally for the receiver) which would be more than adequate for a lot of plastic vessels.

There are no rules on this, every conversion is different, unless you are following the same path as someone else with exactly the same model.

Ashley

[Colin BishopModerator @colinbishop34627]

As Ashley says, Plastic Magic conversions will work perfectly well with cheap conventional setups.

Colin

[Malcolm FraryParticipant @malcolmfrary95515]

Just a few years ago the choice was industrial cells, shortened AA size, but recently the capacity and availability of AAA cells have both improved a great deal.

A standard servo can be considered as a parts mine, yielding a nice motor of about the right size for a wide range of models plus a viable ESC that will run on the receiver battery. The only problem is coupling the motor, but many markets have a stall that sell 5 of them for about £1. They tend to call them "disposable lighters". Anybody got a use for a collection of small gas containers lacking flint springs?

Soldering batteries. Speed and cleanliness. Speed because you want the soldering to have happened before the insides of the cell gets hot. Cleanliness helps the speed. A big iron with a tip about the same size as the area that needs soldering, preferably very hot, helps is vital. Untagged batteries need a bit of attention. They are usually plated – the plating needs to be broken by application of fine emery in the area and given a dab of flux to aid tinning. Best to practice on an old dead battery until you can pick up the battery and shake it about a bit with the bit of wire that you have just soldered to it. In smaal models, its best to not use battery holders – the batteries are your ballast and need to go where you want them, not where a holder dicates.

[Guido SambucettiParticipant @guidosambucetti90794]

Well, thanks a lot for your advice. As you say, it´s not always indispensable to spend a lot of money for a modification so I´ll stick to good old NiMhs. I´ve soldered bateries before with good -albeit not too tidy- results and they are really efficient. I suppose I´ve let myself being dazzled by new hi-tech, haha!

But I still have to find the courage to dismember a servo for its components, though! I´ll try it one of these days and let you know what comes of it.

Thanks again!

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