<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">The lipo pack is lighter.. Guess that's one good thing Troy. Probably the only real benefit except holding voltage over time. Although, even though in a transmitter, I would say the battery should be discharged for storage, and charged the day before anyway. So even holding the voltage over time may not be a real benefit. But the weight thing would be nice.. <br><br><div><strong><em><font color="#0000bf" face="comic sans ms" size="3">Chris </font></em></strong></div> <div> </div> <div> </div> <div> </div><br><br>--- On <b>Tue, 9/23/08, Troy Newman <i><troy@troynewman.net></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;">From: Troy Newman <troy@troynewman.net><br>Subject: Re: [NSRCA-discussion] JR 10X conversion to LiPo<br>To: "General pattern discussion"
<nsrca-discussion@lists.nsrca.org><br>Date: Tuesday, September 23, 2008, 2:03 PM<br><br><pre>Vince,<br> <br>While its not recommended there are several people that have done it. I<br>will say that because you will hear of XXX people that have done it with<br>no problems.<br> <br>JR does NOT recommend it and here is why: The output of the system is<br>driven by a specific design voltage. In the 72mhz stuff the output<br>transistor would get hot if the system was run at the higher voltage. A<br>3S lipo pack comes off the charger at about 12.4-12.6V....A fully<br>charged stock battery pack comes off the charger at about 11.5 to 12V.<br>Here is what I think you should look at. The Lipo pack will maintain is<br>"over voltage" condition for a long time. It will stay above 11.5V<br>most<br>of the time you spend flying it. Where as the Nimh or Nicd packs will<br>fall off to about a 10.5V range and slowly come down from there. The<br>high voltage
condition is only for a few minutes maybe the first flight.<br>The lipo high Voltage condition is a long time maybe 5-8 flights.<br> <br>The issue with the 72mhz equipment was the output transistor would get<br>hot and start to weaken causing loss of range and possible a failure.<br>This is the same problem as running your TX on 72mhz and leaving it on<br>for long periods of time with the antenna down. The module gets hot.<br>This is un-needed wear and tear on the output transistor. Continued<br>abuse like this will weaken the output transistor...In the lipo you are<br>running it in a "high" volt condition for a longer period of time<br>every<br>time you charge the system up. So yes it will work on day #1 and Day<br>#2....but What happens on Day #50 or 9 months down the road. 1 yr later?<br>Its not a good idea as it will weaken the system and it could cost you a<br>model.<br> <br>Fast forward to the DSM technology. Again we have a similar
situation.<br>The output of the system was designed to be run at a given voltage. That<br>voltage is the 8cell (nicd or Nimh) packs. Not the extra 1V of head<br>voltage carried in the 3S lipo packs. I'm not in on the design of the<br>DSM output and can't tell you if it has a similar issue to the one in<br>the 72mhz. However in the 12X manual it states clearly....<br> <br>"Q: Can I use a 3-cell LiPo pack in my transmitter?<br><br>A: No. All current JR and Spektrum transmitters are designed to operate<br>using a 9.6-volt transmitter pack. A fully charged 3-cell LiPo pack puts<br>out 12.6 volts. This higher voltage can overload the power-regulating<br>transistor, causing damage and or failure, possibly in flight. Many of<br>our customers have experienced failures using 3-cell LiPo packs and<br>their use in JR and Spektrum transmitters is highly advised against. The<br>12X system will operate for over 8 hours using the included 2000mAh
NiMH<br>battery."<br><br> <br><br>This being the case the 12X is the latest system from JR. SO if it is<br>not Lipo capable the others are not either. Will it work? Yes, are you<br>taking a chance and risking your model YES.<br><br>I don't understand the rave with the lipo TX packs. The 12X pack that<br>comes standard is a 2000mah pack. A replacement pack would be a<br>2000-2100mah pack also... So you are not going to get more flight time<br>per charge. The only thing is the lipo will not self discharge as fast<br>as the Nimh. However I find the Nimh packs last for a very long<br>time....Still flyable (10.5V) after sitting for a month untouched. One<br>note I usually charge my TX packs with the wall C/10 charger overnight.<br>I sometimes will use a Sirius charger on them or a peak detection<br>charger for a quick field boost if its getting low. However This is a<br>rare thing. 90% of my charging is with the slow c/10 charge rate. At<br>this the Nimh
packs provide extremely good service life and hold their<br>charge well. A guy that is always fast charging his nimh batts will have<br>trouble with the Nimh technology. It doesn't do as well with this type<br>of use.<br> <br><br>By the way JR makes a 2500mah nimh that I have placed in my 9303 and<br>also have installed in an old 10X battery case. It works great as well. <br><br> <br><br>Hope this helps you.<br><br>Troy Newman<br>Team JR<br><br> <br><br>________________________________<br><br>From: nsrca-discussion-bounces@lists.nsrca.org<br>[mailto:nsrca-discussion-bounces@lists.nsrca.org] On Behalf Of<br>vicenterc@comcast.net<br>Sent: Tuesday, September 23, 2008 3:35 AM<br>To: General pattern discussion; General pattern discussion<br>Subject: Re: [NSRCA-discussion] JR 10X conversion to LiPo<br><br><br>Jerry,<br> <br>Are you using regulator? It looks like JR does not like the high<br>voltage. Probably, I am going to try to call or e-mail JR to ask.
I<br>wonder if there is a difference between the 2.4 modules and the old<br>modules in regard taking higher voltage. New TX are designed to work<br>with LiPo. Just wondering.<br> <br>JR sponsored pilits. Can you find out?<br> <br>Thanks for all responding.<br> <br>--<br>Vicente "Vince" Bortone<br> <br><br> -------------- Original message -------------- <br> From: Budd Engineering <jerry@buddengineering.com> <br> <br> > Yep, and I couldn't be happier. <br> > <br> > True R/C 2500 mAh LiPo's, $30 each, fits inside the 10X<br>battery holder <br> > with a minor amount of trimming with the Dremel tool. I bought<br>one <br> > set to try, liked it so well I bought another and converted<br>the spare <br> > battery pack. That way I can charge them out of the<br>transmitter (not <br> > that it matters, the charge rate is so low that the risk of a<br>mishap <br> > is about the same as with NiCads or NiMh). <br> > <br> > I
screwed around with a couple sets of NiMH's for the past<br>several <br> > years, they were a total waste of time, the self discharge<br>rate got to <br> > where I had to re-charge them if I didn't fly within a day or<br>so of <br> > the previous charge <br> > <br> > The LiPo 's pea k up at 12.5 V, essentially the same voltage<br>as a good <br> > set of NiCads, and discharge almost linearly, so it's easy to<br>assess <br> > their state of discharge. <br> > <br> > http://home.comcast.net/~truerc/ready_pack/ready_packs.htm <br> > <br> > Thx, Jerry <br> > <br> > Budd Engineering <br> > jerry@buddengineering.com <br> > http://www.buddengineering.com <br> > <br> > On Sep 22, 2008, at 8:56 AM, vicenterc@comcast.net wrote: <br> > <br> > > Has anyone done the conversion? <br> > > <br> > > Thanks, <br> > > <br> > > -- <br> > > Vicente "Vince" Bortone <br> > >
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