|
Jim Messer -> Sanyo 1400 AE battery problem (4/4/2008 1:09:14 AM)
|
Let me begin by saying that I am not new to this hobby, having now been into R/C for over fifty years. In that time period I have lived through many different battery problems - going back to the olden days of lead/zinc cells that, if you were lucky, would last an entire flight.
So this new problem is one I never expected to witness.
I will start by saying that in my giant scale airplanes, for the past several years, I have been using two flight packs made up of 4-cells each - Sanyo KR1300SC mah that I make myself from individual batteries with solder tabs. These twin packs have provided at least 1 to 1.5 hours of flight time in my giant size airplanes. I use 1300 mah cells because my chargers can be programed from 50 to 140 mah charge capacity, so by setting them at 130 mah, that is the correct charge rate for these batteries. In the last ten years, I haven't had any problem that I can remember.
Last week I looked into one of my big planes, and noted that the date on the battery packs was 2/06 - so I thought - I'll get some new ones, although they were still holding a charge and flying the plane as good as ever.
So I went to TOWER (where else) to purchase some new batteries. Lo and behold - the KR1300SC batteries that I have been using for the past ten years are no longer available. So I look over the list and order 16 of the Sanyo KR1400AE batteries, which are about a buck each more expensive, and which I thought to be an even better battery than what I had been using.
After making up four new flight packs, I replaced the two-year old batteries with the new; charged them for 24 hours, and checked them both with a volt watch and a meter. Whereas the old batteries always showed full charge on the volt watch, they also showed about 5.6 volts on the meter fully charged. After 4/5 ten minute flights, the volt watch in the plane usually still showed at the top or one light below.
My first concern was that the new KR1400AE batteries only showed 5.1 volts after a 24 hour charge, but did show the top light on the volt watch.
Anyway, it's off to the flying field today, and I only had the volt watch to depend on, as I had left my meter at home. Guess what? After one flight of less than ten minutes, when I landed the volt watch was down to the 3/4 green light, and about ready to go into the yellow. I didn't dare to make another flight.
My brother, Bill, purchased these same 1400AE batteries about a month ago, and he told me that he was having the same problem - and he too has concluded that there is no capacity in these batteries.
Next step: Get on the phone with Tower, and talk to a young lady who questioned my receiver, my servos, and the like. She didn't seem to comprehend that the older/cheaper batteries were clearly outperfroming these new ones at least by a factor of 5 or 6. Bottom line - too bad for me - she says there is nothing wrong with these batteries, and nothing can be done about it, and because they had been soldered to, they were un-returnable. (How else could I find out their performance if I didn't put them to the test?)
I write all this to warn others that the Sanyo KR1400AE batteries are in my opinion garbage, and should not be used in a valuable airplane. For me, that lesson cost 60 bucks - down the drain.
So today, I reordered 16 Sanyo KR1500SC batteries, that should be more in line with those I have experience with. No sense in risking a $3000.00 airplane with batteries that aren't 100% reliable.
So - if you need to buy new batteries, better stay away from those KR1400AE Sanyo batteries, unless you are flying a tiny R/C airplane.
I'd be curious to know if anyone has an explanation for this poor performance, or has anyone else witnessed any similarity. How about you battery gurus, that know all there is to know about batteries, chiming in here. I'm not too old to learn, and would appreciate some kind of meaningful explanation if there is one.
|
|
|
|
