Building new NiMH Packs...

While shut-in sick over the last few weeks, I took an opportunity to build a batch of 5 cell NiMH 3600 mAh packs for some of my airplanes. They're bonded, soldered, and covered in this heavy-duty heat shrink sleeve. One of these is going in my Kadet Senior first, once I figure out where the fuel tank leak is coming from. 

More battery problems, Kadet Senior...

Wow...I've been working on these airplanes since back in November of 2018. When you stop flying for a few years, everything goes bad. I've repaired my portable glow driver, my power panel, my electric starter, my fuel pump, and pretty much all of the batteries in all of my airplanes. Oh well, at least it's winter and I have time to do it. When I pulled the Sig Kadet Senior down, I discovered a bunch of problems...bad flight battery, leaky fuel tank, and a broken exhaust header on the engine. Here, you'll see the bad battery and the packing from around the fuel tank that shows the evidence of a fuel tank leak. Hopefully, by the time warm weather is here, I'll be all repaired and ready to fly...here's a few pics from the tear down of my Senior. 

Hangar 9 Twist Battery Check Out!

I can't believe, that after 2 years in storage, the Tenergy 5 cell 2000 mAH NiMH battery in my Twist actually checks out to be good. It looks like the 'Red Neck' battery maintenance system described in my previous post actually worked. Over 2 years of hitting the battery with approximately 25 mAH of charge per day while in storage, and it cycles as if it were new. 

 It's nice to get lucky every now and again :-) Now, it's time to move on to the next airplane and see how it checks out. 

Dave AMA119484
http://www.RCDave.net

More from the Mothballs...

Still getting things ready to go after a 2+ year break... I pulled this 12 year old Hangar 9 Twist .40 down, and put it on the Accu-Cycle. It was stored on my "red-neck" battery maintenance system for the last couple of years... That consists of a conventional 50 mAH charger connected to a Christmas tree timer. I have it come on for 30 minutes/day, and then back off. I never bothered to check it, other than to verify that the charge light was still coming on when the timer was passing power. So far, it looks as if the 5 cell 1500 mAH battery is fine. One more cycle to verify, then on to the next bird. So far, so good!

Dave AMA119484
http://www.RCDave.net

Checking Flight Batteries...

Well, here we go, after a LONG period of inactivity. It's been about 2 years since I've had any of my birds in the sky, other then little park flyers and such. I installed new batteries in everything about 2-1/2 years ago, flew a few times, and put them up. Now, once again, all of my batteries are shot. I'm trying to cycle them and see if they're worth using, but I have a bad feeling they'll all need to be replaced. In these photos, you'll see an old 16 cell NiMH RC Car pack I've cut open to cycle cell groups to see if I can salvage any of it for use as a 4 or 5 cell flight battery. So far, these cells seem to cycle at about the right mAH rating. Next, to leave them sit a few days and see if they loose any charge from internal leaks...

I use a pair of Hobbico Accu-Cycle units on 12 VDC supplies, and keep them cool by pushing air through their ventilated cases with a small 12 VDC muffin fan. These work pretty good, but Accu-Cycle units will generate a lot of heat in the cycle mode with the discharge rate set to .300 mAh.

Dave AMA119484
http://www.RCDave.net

RX & TX Battery Maintenance on the Cheap!

Here's a tip on something I've been doing for 30+ years with great results. Most of us are guilty of charging our airplanes & transmitters for a day of flying, but never making out to the flying site. Our airplanes will sit around a few weeks until one day we have an unscheduled opportunity to go fly, only to find out that our gear isn't ready and waiting...This is especially common on systems where the batteries may be a little older and the batteries don't hold a charge quite like they used to, due to the internal leakage that comes with age of Nicd and NiMH batteries.

There are a number of trickle chargers and such out there to combat this problem, but I found a simple cure that keeps my gear topped off and ready to go very inexpensively. I use the standard chargers that came with my radio systems, in conjunction with a cheapie Christmas tree lighting timer. These timers are often found at Walmart for $3 or so, and can easily handle the very low current requirement of multiple chargers. Connect the chargers to the timer, set the timer to come on for maybe 30 minutes once or twice daily, and forget about it. It's that simple, and I've never had an issue as a result of doing this. Here I have several transmitters and chargers in maintenance mode...

Here's a closer look at the chargers in my workshop, ganged up on a timer. 

 

All of the airplanes in my ceiling mounted aircraft hangars are wired fr maintenance when hanging in storage. Notice the charger in the upper LH edge of this pic...
 

Another timer in the garage feeding some of the aircraft in another ceiling hangar. If I want to put a solid overnight charge on, all I have to do is flip the switch on the timer to the "manual on" mode. 
 

A Hangar 9 Twist and a Spoiler ARF hanging in storage while in maintenance mode. 

Another timer for a different batch of aircraft. It doesn't matter what the time on the timer is set to, nor what time I have it come on for 30 minutes... Very simple!

Dave AMA119484
http://www.RCDave.net