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| Electronics Discuss radios, chargers, etc... |
Topic Review (Newest First)
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| 11-09-2014 09:20 PM | |
| cosmith |
Re: Newby RX Battery Question I tend to agree with others here...if you are buying a new battery anyway, get a Life battery. They are better in every aspect, and depending on your source they don't have to cost more. Also, if you are concerned about voltage, keep in mind the 6.6v you will get from a Life is less than a freshly charged 6v NiMH. |
| 11-09-2014 07:26 PM | |
| kip51035 |
Re: Newby RX Battery Question I just checked my battery drawer and there is still three cells from 24 cells that came with my used German radio in 1964 they still work fine. Over the past five years I have thrown out a coffee can full of NICAD and NMHi batteries that quit working or started to leak. Age does not seem to be a factor in a cell going dead. NMHi batteries should be charged at 1/15th to 1/20th of their capacity until they get warm. Full charge on a NMHi pack should produce 1.36V to 1.38V per cell. Like I said before the voltage comes up really fast but the capacity takes a long time to fill. Check the voltage and record it then put it on the shelf for a month. Plug it into your aircraft or what ever and operate it for twenty minutes. if one cell goes down to less than 1.1V or the voltage drops of quite rapidly, do not use it. I have replaced many cells in both receiver and transmitter packs. I just went through about twenty pack that I had not been charged since last January. |
| 11-01-2014 04:48 AM | |
| floyd |
Re: Newby RX Battery Question I've just recently bought some brand new 2850 mah NIMH for my camera that charge the same way as all my NIMH do. They won't get a full charge unless I charge at .3mah maximum. I can put almost 3500ma into them at a low .3mah charge rate before the charger goes to trickle. Floyd |
| 11-01-2014 03:35 AM | |
| davidmc36 |
Re: Newby RX Battery Question I know what you mean about the old NiMh. I have a few non-RC use batts that won't charge on the smart charger, just kicks it off with High Voltage Error. The only way to get a decent charge into them is with a dumb wall wart low ma charger until they start to feel a bit warm. Wouldn't put them in a plane though. The new ones work fine on the smart charger. |
| 10-31-2014 09:31 PM | |
| Flypaper |
Re: Newby RX Battery Question That's the proper way of doing it Floyd. I have a number that are quite old and still going strong. I have had the odd bad one. |
| 10-31-2014 08:23 PM | |
| floyd |
Re: Newby RX Battery Question I've got 4.8 and 6 volt NIMH battery packs that are over ten years old that still cycle like the day I bought them. But not one of my NIMH will get a full charge unless I charge at no more than .3 MAH. Any higher charge rate and they won't take a full charge. And I've tried more than one charger with the same results. The voltage goes too high and the charger kicks to trickle before they get a full charge. Floyd |
| 10-31-2014 07:57 PM | |
| davidmc36 |
Re: Newby RX Battery Question 5 year old NiMh? Crap shoot at best. I had a couple that were bought new and did not get into use for nearly a year. I would not trust them until I had done tests with large resistors hooked to them to see what the voltage looked like under heavy load. Although resting voltage is a half-decent indicator of state of charge, it tells you nothing about how it will stand up under load and a regular chemistry NiMh that sits on the shelf for a couple months could be @ 50% or less. I always top up a NiMh right before I head out to fly, even the LSD variety. For a five cell NiMh I put a 5 ohm 10watt resistor on it and made sure the voltage did not sag very much. Left it for about 30 minutes to see where the voltage fell to. From there I could calculate within reason what the actual capacity would be. It worked out to about 95% of what the label said it should be so I was happy with that. I use only 5 cell NiMh for planes that have Rx battery, gives a bit more "overhead" for periods of high demand. Most of the electrics run off the BEC. As new planes get built they will be getting LiFe |
| 10-31-2014 12:06 PM | |
| bhughes |
Re: Newby RX Battery Question In that case one life pack around the 2300 size would be just right |
| 10-31-2014 10:52 AM | |
| Skinner |
Re: Newby RX Battery Question This 1/4 scale SIG J3 Cub has a Quadra 35 gas engine in it and it is a pull start! LOL. Therefore I dont have to worry about an ignition system drawing on the battery, just the RX and 5 servos (2 ail, 1 rud, 1 ele and the throttle). Kip - This battery was charged and has been sitting for almost 2 weeks. This morning it still read 5v when I checked it. I just set up all the surfaces and ran the engine for a bit this morning. Hopefully I will have time (and the weather) to maiden it on Sunday. Thank you for your help so far. |
| 10-31-2014 10:27 AM | |
| bhughes |
Re: Newby RX Battery Question Throw that nimh unreliable heavy old junk out and buy a life pack. Life batteries are awesome use them all the time. And yes I even use the same batt for the receiver and ign. If I was using a powersafe receiver I would use the deans off the life pack for the receiver. And the jr style lead for the ign. Been doing it for a couple years no problem. If you charge a life pack today you don't have to let it sit for 5 months and check the voltage. Cause it will be the same unlike nimh which can loose a couple hundred mah in just a few hours. |
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