Vapor Trails,

I don't think it was the connector itself as it's tight and the engine wasn't running. It's something about the battery out of the dean lead because I had voltage through the balance connector but nothing to the board. I'm not a battery expert so I have no clue why TWO batteries would shut off but they were not delivering current to the board with some fairly benign wiggling of the servos while setting up programming. The last time for "no current" was the following morning when I was trying to power up the board...nothing. Here is the explanation from another fellow's experiences with the same batteries. These are the TBM 6800 Li Ion (not trying to bash them, just providing information):

Originally Posted by bmclaughlin View Post
Hate to disparage any product but I too have used the Troy built packs for many years, 2600's, 5200's, the 2800's and 5600's and now have issues with the new 6800 MA packs, Lost my 50% Pitt's Challenger with an unexplained electronics failure on flight number 25.... all electronics functioned properly the next day when checked?


Convinced myself it was a Power board failure. Just put a new set of the 6800MA's in my DALTON/PAU 300 and after Couple of engine tune sessions and working out a header leak al was working fine. Put the cowl on and the following weekend fully charged was about to go up for the Maiden, checked the controls before going to the starting pad and hit my snap switch and all electronics shut off! Nothing had any power. Unplugged the batteries, plugged them back in and everything was fine! Rowed the sticks and then hit the snap switch again and all shut down. Tried various things and found it would not power up on just a single battery but would require 2????? Took it all home and found that if I put a v-meter on the deans output reading 8.25V... tapped a small screw driver on the back of the deans charge lead and not even a spark, meter instantly 0.00V. Unplugged meter and plugged back in 8.25, both batteries same result..... grabbed a 5800MA that was 5 years old and likely had not been charged in 6 months and a single battery powered up the plane and worked fine under any load. Then did the same with the V Meter plugged in the deans with it and brushed the back of the JR plug to again created a momentary but fairly low draw short ( no expert but you can't pull huge current through a JR Plug).... it generated a small spark and the V meter barley dropped and continued working. Have tried to Contact TBM but can't reach on the phone. Bought some 5800MA Duralites and planes was maidened this weekend and all is fine.


I only use LiOns - I like the capacity Vs. weight and in must cases my batteries are not mounted in and easily accessible place for balance reasons and never remove for charging.


Will no longer use the Brand from TBM but until I went to the new 6800MA batteries had NEVER had an issue and I have had dozens of them.

Dielectric grease will not help in high vibration or intermittent connections it is non conductive grease to prevent corrosion or moisture intrusion

Hi, some Li-ion packs will have a circuit protector that will shut off the batteries when it detects too high a discharge current. Sometimes you have to remove the load and then re-attach. I do not know if the packs you have contain a circuit protector but this might be the issue. As far as Deans goes, I have seen mating issues, especially with knock-off females. But in general I have also seen this with two supposedly good actual Deans. This is one reason I am starting to offer XT-60s on new products as I get them out this year. I will recommend the XT-60 over the Deans for quality of connection and service life.

Originally Posted by Deckeriv

Okay, think I found the culprit. When I went into the shop to begin the elimination process, after turning on the transmitter, I had no power to the board. I had a new pin switch so I installed that and still nothing. So it's not the switch. Checked the batteries at the balance lead and they appeared to be fine. Since a friend had problems with these 6800 batts on the deans lead I took them out and plugged in a new battery I had laying around. Pulled the pin and instant power. I'll get the batteries replaced and do a lot of servo exercising before the maiden but the batteries now make more sense than anything. Got a new board coming just to be on the safe side but I suspect the batteries. I am still going to send the board to Bob to inspect and get a clean bill of health but right now I think it's not a board issue.