Aero120 Posted February 2, 2009 Share Posted February 2, 2009 Hi, I've had an mcx for a couple of weeks and its great. Having an Ic outdoor heli I find it fun and easy to fly and so its not had too many knocks. However the flight time has suddenly dropped to just over a minute before the onboard Led starts to flash and the power reduces. I've replaced the charger batteries and checked the heli to make sure nothing is binding. The recharge time has also dropped so it seems either the battery has lost capacity or the charger is stopping too soon. Has anyone had a similar experience? Quote Link to comment Share on other sites More sharing options...
Ultymate Posted February 2, 2009 Share Posted February 2, 2009 Paul, if it's powered by lipos their performance drops off considerably in cold temperatures are you flying in a cold environment? Quote Link to comment Share on other sites More sharing options...
Aero120 Posted February 2, 2009 Author Share Posted February 2, 2009 I fly in in the house and its quite warm in here. But I'll try warming the battery in a pocket and see how it goes. Thanks. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted February 2, 2009 Share Posted February 2, 2009 hello paul-let the lipo cool between flights-they're not keen on a quick discharge and quick charge straight away afterwards--over time i've seen a few die prematurely due to this ken anderson. Quote Link to comment Share on other sites More sharing options...
Aero120 Posted February 2, 2009 Author Share Posted February 2, 2009 Thanks Ken. I have let them cool for a short while but I have been charging and discharging in quick succession to get as much airtime as possible! Ultymate I've tried warming the battery in my pocket but no difference in its performance. Quote Link to comment Share on other sites More sharing options...
Andy Dockerill Posted February 2, 2009 Share Posted February 2, 2009 Paul, There may be several issues here. The supplied charger chargers at about 3 times the rate you should recharge lipos at 3C instead of 1C. 110mA battery should be charged at 0.1A not 0.3 which the supplied one does. It is possible that the battery has been cooked. So if you have a decent charger use that to charge the lipos. More likey is that the connector wires that go into the small white plug where you plug in your battery are loose / damaged . This is well documented on other sites. Just this morning i re-soldered this plug because all five of my batteries were giving less than one minute flights. I know my lipos were all ok so did the fix and all is good again. Hope this helps but if you're into Ic engines dont know if you will have the gear needed. Andy Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 2, 2009 Share Posted February 2, 2009 Are we sure about the recharge currents being 3C Andy - where do you get that data? Itcould equally be that the supplied charger merely does a "fast" charge which involves only charging to 90% capacity or so. Quote Link to comment Share on other sites More sharing options...
Andy Dockerill Posted February 2, 2009 Share Posted February 2, 2009 Timbo, I don't know if the forum rules allow a direct link , but a well known RC group of forums has a very large thread about the MCX. It has been discussed heavily and mods suggested to reduce the charge rates. I myself simply connect the Mcx charger to my Sigma eq with patch leads so I can charge at 1C. Edited to point out rewired inside Mcx charger and batteries removed etc!! Andy Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 2, 2009 Share Posted February 2, 2009 Yeh Andy - no problem with the link mate - lets have it ! Is it RC groups ?? Quote Link to comment Share on other sites More sharing options...
Aero120 Posted February 3, 2009 Author Share Posted February 3, 2009 Hi, Thanks for the info Andy. I've got some 3 cell Lipos for an EDF so I have Sigma Pro Peak Lipo charger and some knowledge of Lipos. I agree that 3C instead of 1C is bad news. That would fit with Kens info. I've certainly been battering the battery to keep flying the little beasty. Got a couple of new Lipos on way to work today and just flown it with a new pack and its back to decent flight times. I'll see about stripping the charger tomorrow and fitting leads to plug it into the Sigma. Is that OH88 on your Avatar Andy? Quote Link to comment Share on other sites More sharing options...
Andy Dockerill Posted February 3, 2009 Share Posted February 3, 2009 Timbo, yep its on RCGROUPS. I've included the link. It's in multi rotor helis- Blademcxmods. The thread deals with lots of topics regarding the mcx but this link takes you to a fairly typical post from someone who obviously knows more than I would ever care to know about batteries and charging. http://www.rcgroups.com/forums/showpost.php?p=11081642&postcount=778 (Hope the link works- followed your instructions Timbo but couldn't see an " insert" button on the window that opens). Paul, interesting the heli is back to normal flight times with a new battery. Kind of points to the old ones being shot. And no, not OH88, XA97. Andy Quote Link to comment Share on other sites More sharing options...
Aero120 Posted February 3, 2009 Author Share Posted February 3, 2009 Andy, Thanks for that. It makes a lot of sense. What's the best way into the standard charger? Are there screws under the rubber feet? I thought OH88 was unique in having the yellow extend below the side windows, but it obviously has a twin. Just a thought, more for bigger Lipos, but do many people have access to a fire extinguisher incase a pack turns critical? I had a word with a chap who services fire extinguishers at work and he recommed a blue "dry powder" type which would put out a lipo fuelled fire. Also copes with petrol which is handy as my Extra has both petrol and a Lipo pack for the ignition . Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 3, 2009 Share Posted February 3, 2009 Hi Andy - not read the whole thread yet...but looks like some good stuff there for this little wonder. I have changed the word "insert" ( in the linking tutorial ) to "OK" The tech guys keep changing the system a bit here and there, and I dont always remember which bits to mod Quote Link to comment Share on other sites More sharing options...
Andy Dockerill Posted February 4, 2009 Share Posted February 4, 2009 Paul, The avatar is one of the two Helis used by herts police. It's either XA99 OR XA97. They are flown by The Chiltern Air Support unit for Herts, Beds and Thames Valley Police. a better pic is here. http://www.flickr.com/photos/planegeek/170751747 I believe they are G-CPSH Eurocopter EC135T2 but I could be totally wrong. ( I know less about full size helis than RC ones lol). With regards to lipos I charge mine in a brick built out-house-shed. I've seen the videos and read some horror stories and should really use lipo sacks or something like an old ammo box but thats all for another thread. How are the batteries going? Still getting full flight times on the new battery? Yes peel off the rubber feet to get access to the screws. I drilled two small holes in the case and soldered on some wire connected to 4mm bannana plugs. I'm no expert but if you require a couple of pics I could sort something out for you. Obviously an alternative would be to make up some patch leads to fit between your charger and the battery directly. I could n't find a source in the UK. I think they might be LOSI connectors but not sure and as I have plenty of wire and 4mm plugs it was an easy job. Regards Andy Quote Link to comment Share on other sites More sharing options...
Andy Dockerill Posted February 5, 2009 Share Posted February 5, 2009 Paul, MCX CHARGER REMOVE RUBBER FEET TO ACCESS SCREWS WIRING INSIDE SLIGHTLY OUT OF FOCUS BUT A CLOSE UP Think its all self explanatory. Andy Quote Link to comment Share on other sites More sharing options...
Aero120 Posted February 5, 2009 Author Share Posted February 5, 2009 Thanks Andy My Lipocharger won't go as low as 110 mAh but it can get nearer than the standard unit. I'm going to put those leads in as you have and hopefully have a battery pack life of more than two weeks! Quote Link to comment Share on other sites More sharing options...
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