(That ought to get their attention)
Okay I got this battery which is a 4-cell 4.8V 350 MAH 2/3AAA NIMH. Its made by Great Planes and it says Electrifly. I got it charged up using the charger that looked like the right one according to Tower hobbies. I liked the Idea of this battery because its light weight and small to fit in my new footy.
Okay, here’s what ahappenned. The stupid battery has on it what appeared to be a “Universal Connector” this also according to the web site. I innocently thought Okay, that probably means I can just plug the silly thing into any old reciever. Right? WRONG!! So I plugged it into my Futaba two channel AM Reciever and I noticed right at that point that it started to get really hot. Much hotter than it was when it was charging. This didn’t make sense to me because I thought things got hotter nly when you add engergy to them. Anyway I then suddenly realised that the thing was starting to melt
so I immediately tried to pull it out but it was so hot I couldn’t touch it. Wen I finally ripped it out, I ripped out half the deck of the footy in the process. Never expected this.
My question: I have another one of these batteries of the same kind. Should I try again and pay better attention to where the red and black wires go? will it explode again? should I yell at Great Planes for not warning me about this? what’s the best way to get the same sized battery in there safely? where can I find another brand? already tried Towerhobbies. Will look again.
I have a big fat 500 MAH battery that works but I can’t make it fit in the little boat.
Never heard that Myself, if true, seems a bit restrictive if bolth types of batteries are readily available and one is lighter. Thats just one persons vote.
Dimly recall discussion about allowing micro servos like on Park Flyer Planes.
The batteries are really a very important part of the rule.If the rule allowed any type of battery I think you would see very different boats (footies)to what we have currently.The design displacment and ballast ratio are very much effected by battery weight on such a small yacht.
Bad luck with your batteries there John,I will let the others comment on that,not my area of expertise,asuming I even have an expert area!!
Cheers
Brett
Did you determine exactly what was shorting the battery terminals together? Fortunately, those thin wires will melt first, but can still get really hot!
NiMH cells can take some abuse and still work. If they vented (which probably didn’t happen in your case) then you’ve lost a significant portion of the capacity (BTDT). Si if you didn’t melt the covering, you can probably just replace the connector & wire, then cycle & test it for capacity, and probably put it back into use.
Hindsight will tell you to check your polarity on an untested/new connection, then put in a keyed connector, and use the same battery (or two) on the same radio. You didn’t hurt the receiver, did you?
I like the idea of using the AAA batteries, and you went a step further with the 2/3 AAA, but you need to learn to balance the boat the the AA cells too. Especially if you think you’ll be showing the innards to visitors. You want others to see the ‘correct’ way to outfit the boat so they don’t get the idea that it’s too complicated or specialized.
Sounds as if you are aiding and abetting the breaking of the rules when you say ‘like the idea of using AAA batteries’ and also praising the use of 2/3 size AAA.
Nothing wrong with using AAA cells in a sailboat, just don’t let people see you do it in a Footy. I have said that months ago. Mr. Storrow is welcome to outfit his boat any way he wants too. I’m sure he knows to switch the battery pack for regulated sailing, or to tell an onlooker that there really should be a pack of AA cells inside (which is best for beginners). Did you read the entire statement I made, or just the part you didn’t like?
Concerning your original problem. The universal connectors are great but they can be plugged in backwards - no key like on a Futaba connector. All you have to do is keep in mind that you want the black wire at the end of the rcvr and the white wire at the end of the slot where the main body of the rcvr is and of course the red in the middle. Sometimes I put a white dot on a receiver to remind myself where the white wire goes.
A lot of servos do not have black, red, and white wires. In one case brown equals black, red equals red and yellow/orange equals white.
There is a website that you might be able to find that talks all about this subject. It was mostly set up to talk about the total lack of similarity of the old Airtronincs and Futaba wiring, I believe.
I actually agree, now that I think of it, that keeping the battery rule a constant in the Footy is important for so small a boat where the weight of the battery is significant.
I think I’ll stick with good old trusty AA Nicads for now, the other ones were too freaky.
Do you think NiCads would be good for a biginner boat? The rule allows only AA cells, but there is no mention of the cell chemistry. In my mind, using AA NiCad cells is as difficult as using AAA alkaline cels, if not more difficult because of cell charging & care.
No. I wasn’t kidding. To use AAA alkaline cells, the only thing needed is a different holder, which you can buy already made up with a connector; the same as for AA alkaline cells. AA nicads need a charger, you can’t run them down flat, and need to cycle them to keep the capacity. Same with NiMH cells.
I know some older guys that won’t use rechargeables in ANY model- boat or plane, for just those reasons.
I continue to stay with NiCads. Four AA’s give me 6 volts. The Tx “tells” me when they are going “south” - whereas NiMh have screwed with me for the last time. Even here at work we have reverted back to NiCads for Police digital cameras. Too often a deputy would take three photos - and have number 4 lost because batteries went bad - no warning … one minute good, next minute dead (or low).
Now some of you (say) you don’t have this problem, but it might be a good time to explain to us (others) “How Come?”
The electronics side of things is my weak-point, so I’ll be interested in what people have to say.
I had always used NiCads, at both the transmitter and receiver end, but as my charger plugged into 230v (and was not switchable), I gave it away when we moved to the US last Fall. With the new season about to start, I’m in the market for a new charger and probably new batteries.
Maybe we should move this off the Footy thread and start a new one - we’ve gone off topic, and this stuff helps us all - not just the Footy guys.
How do you get 6volts from 4 cells that are supposed to put out a Maximum of 1.35 volts each? Were you referring to alkalines?
Wis-
I’ve had NiMH packs that stay full for weeks. You can get ones that go down slower or faster. It depends on the internal resistance, which depends on the way that batch of cells were made. F/E racers will select EACH cell in a race pack for that reason.
Yikes ! Dropped a couple of important words somewhere along the line…
"I continue to stay with NiCads. Four AA’s give me 6 volts. "
I continue to stay with NiCads [COLOR=red]for my transmitter. For my Rx, four alkaline AA’s give me 6 volts. The Tx tells me when they are going south. [/COLOR]
I didn’t include that I use the 1.5 volt batteries to give me maximum torque/speed for my Hitec 815BB sail servo. The Tx only has to get the signal there, while the Rx/servo (Y harness) has to provide the power and speed for sail control.
Sorry about that - I usually compose in Word (for spell check) and who knows where those data bits are now lying about?