Rich Griff Posted November 7, 2022 Share Posted November 7, 2022 I have tried 4 max, component shop and wheelspin for a 3.2 volt 60mah Fe ( life ) battery for a Gadget Tini helicopter. Anyone know of a specialist battery supplier that may stock these please ? Thanks in advance, rich. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted November 8, 2022 Share Posted November 8, 2022 Look on the Internet / ebay .Lots of tiny cells available Any reason a li- po can't be used as you are far more likely to find one of those. Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted November 8, 2022 Author Share Posted November 8, 2022 Thanks Ed, will have a good look today. 3.2 volts, lipo voltage higher ( 3.7 v ? ), Half a volt, may "roast" the helo electronics/board... Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted November 8, 2022 Author Share Posted November 8, 2022 (edited) Thinking about this, perhaps a 3.7 lipo and a resister "potential divider" chain to tap 3.2 volts, diode even, but a diode may "reduce" voltage tooo much ( down to 3.1 or 3 volts ) ? Any thoughts ? Will continue search for life battery, perhaps there are some suitable voltage regs out there I could utilise ? Edited November 8, 2022 by Rich Griff Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted November 8, 2022 Share Posted November 8, 2022 Hi Rich I bought a dozen mini helicopter returns from a stall at Wings and Wheels some years ago. Every one had battery problems but most just hadn't been charged properly. They were all fitted with tiny lipo cells and were charged via a USB lead. It may be that Life cells were used as " they were available" as is often the way with these toy type helis. You could put a shockty diode in the circuit that will drop the voltage by approx .5 volt. Quote Link to comment Share on other sites More sharing options...
PatMc Posted November 8, 2022 Share Posted November 8, 2022 Best use 3.3v in any search for LIFE batteries as they are usually quoted as 3.3v per cell. A single resistor isn't a potential divider, & not a very satisfactory way to reduce the voltage. Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted November 8, 2022 Author Share Posted November 8, 2022 (edited) Potential divider, two resistors capable of handling the "power" , quarter watt maybe. Two resistors same value would half the voltage, divided, a " chain"...centre tapping in this instance So get the proportions correct and end up with 3.2v from 3.7v at the centre tapping... A feel some Kirchoff and nodal analysys brewing... My data book is AWOL...3.3 v reg ts2950cz-3.3 at 72p but need data book for further info.... No smoothing needed as DC to dc.... Wieght is the problem... Thanks for the Schottky diode suggestion, need my data book, wth are you ! Thanks for the suggestions so far....much appreciated... Don't think one of those super capacitors will give enough duration..... A sc was used on the twin motor indoor flying models in Bethesda. Edited November 8, 2022 by Rich Griff Quote Link to comment Share on other sites More sharing options...
gangster Posted November 9, 2022 Share Posted November 9, 2022 A potential divider is no way to drop voltage when the current demand is going to vary. The load is effectively a variable resistor across one side of the divider. A three terminal regular could maybe used and they can be varied from their nominal voltage Quote Link to comment Share on other sites More sharing options...
Peter Christy Posted November 9, 2022 Share Posted November 9, 2022 The problem with a 3-terminal regulator is that it needs a certain amount of "headroom" to operate. The voltage drop we are talking about here is very small, so probably not enough headroom for a regulator. Best option is an ordinary silicon diode of a suitable current rating (typically 0.6-0.7V drop). Germanium diodes are typically 0.3V, but are usually low current types. Some Schottky diodes have a very low forward voltage drop, so choose carefully! Whichever way you go, I would recommend a small smoothing capacitor after the diode (tantalum beads are very small!) to reduce potential issues with motor noise. -- Pete Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted November 9, 2022 Author Share Posted November 9, 2022 Head room yes, various currents yes, still looking for my data book which lists component data etc.. Keep it coming chaps, all good stuff... Quote Link to comment Share on other sites More sharing options...
Don Fry Posted November 9, 2022 Share Posted November 9, 2022 (edited) Left centre thoughts, to paraphrase modern speak, but is it not possible, the thing will go right nice on a common or garden LiPo 3.7v nominal. Save a load of hassle. Cheap too. It’s only a 12% or so volt increase. Edited November 9, 2022 by Don Fry Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted November 9, 2022 Share Posted November 9, 2022 I agree with Don, 1/2 a volt increase isn't going to fry anything, if it were mine I'd just do it and fit a LiPo. It seems LiFe cells only come in very limited sizes. Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted November 9, 2022 Author Share Posted November 9, 2022 Fry...magic smoke...thanks Don.... Mo has a lab powersupply that is fully adjustable that I can loan and do a bench test. If the helo survives, new lipo it is I think... Quote Link to comment Share on other sites More sharing options...
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