Did I Do Something Wrong....
 

Sorry for the long post, I am a bit wordy.
My wife bought me a NexStar Select EP with the Hobbico Dual Peak Charger and the two needed Electrifly 3600 battery packs ( I also have a glow trainer but that is a long story. ) I took the Peak Charger and made it panel ready for my field box as I understood that I needed to connect the Peak Charger to a 12V DC battery ( I have a TorqueMaster LC 12V 7Ah battery in my field box ). Fisrt question is, how long does it take for these things to be fully charged for the first charge and then subsequent charges. I was under the impression that it would be less than one hour as the manual says the Dual Charger will automatically cut of after 57 minutes to prevent over heating. When I first plugged them in, it took off and seemed like it was quick charging them. I stopped babysiting them after four hours. At that time the LED on the Dual Charger was still blinking amber stating the it is still charging. It is supposed to go green when complete. I decide to uplug it and let it sit over night. I plugged it back in yesterday and after about 30 minutes the whole thing cut off. Come to find out my field battery (which prior to starting the dual peak charge, I had charged for 16 hours ) was completey out of juice. So I am wonderinng, am I not suppoed to be charging things the way I am or do I have a defective field battery as it is new as well. Thanks.

RE: Did I Do Something Wrong....
 

Your field battery just doesn't have the capacity. At best, you could get one full charge out of it. Even fully charged it only has approx 7000 mAh of capacity and to charge an almost empty 3600 Electrify you're using half of it, or more as there is loss between supply and what's going into the battery. As your Electrifly batteries charge the voltage of the field battery drops to the point that the charger can't do its work. Try it off of a car battery and see what happens. More than likely your batteries will charge up fine. I've even had this problem charging large LiPo packs from a car battery, the charger complains that the input voltage is too low. Guys who are really "into" the electrics will often use a DC power supply, for the charger, plugged in to an AC outlet at the field or have a deep cycle battery they bring for charging.

P.S. It's possible your field battery is defective. Did you charge it before trying to charge the Electrifly? Even so it won't be very satisfactory as a source for your charger due to its limited capacity.

Edit: Spelling correction.

RE: Did I Do Something Wrong....
 

Jim, thanks for the reply. I suspect you are correct that the field battery does not have what it takes to charge the Electrifly's. I guess I just assumed that it would work. Oh well, I am a newbie. So now, can someone point me in the correct direction as to what I product need to buy to charge the Eletricfly's if I do not have a car battery laying around.

RE: Did I Do Something Wrong....
 

If you're not able to use, for example, your car battery, you can purchase a 12V DC power supply. They are available at hobby shops and Radio Shack. Prices vary depending upon how many amps the unit will supply. I suspect that a 10A power supply will be sufficient. Remember though, that at the field, unless you have a 120V AC outlet available, you will need to charge from your car battery.

RE: Did I Do Something Wrong....
 

http://www.hobbypeople.net/gallery/158300.asp

RE: Did I Do Something Wrong....
 

Thanks so much for your posts Jim and Clay. I just would rather not pop the hood everyime I needed to charge them up. The 12V DC Power Supply is exactly what I am looking for. Also, I do have an an 120V outlet in the bed of my truck if I were to need it at the field. Thanks.

RE: Did I Do Something Wrong....
 

Please do not take this the wrong way - I just really have to ask the quesiton.... If you have a 120 volt outlet in the bed of your truck, what is the power source? Inverter or generator???

If it is just an inverter off the truck battery, then you will kill the truck battery even faster. If you have a generator, then I want to go out flying with you:D Unlimited power!!!

Another suggestion is to fully charge both batteries the night before you plan to fly (along with your TX and RX batteries). Then the next day, just put the batteries on the charger for 10-15 minutes to "warm them up".. The NiMH batteries give you better performance if they start out a little warm. That will get you two flights in before you even start to chew up your charging capacity.

Lastly, I'm currently using one of these for my limited charging.. 18Ah battery, air compressor, 12v outlets, 400 watt inverter, LED lights and car jump start. It will also be my air compressor for retracts...

RE: Did I Do Something Wrong....
 

TEberg, no I will not take it the wrong way. I asked a question and you are giving me a polite answer. I have an inverter in the back of the truck and was going to use that, but as you point out, that would have been another mistake made by me. ( That is why I am asking questions. I am really new to all of this, so your answer really helped me out on that one. However, I do have a generator as well, so I could just throw that in the back of the truck and like you said, unlimited power. Ha HA Ha. Actually did not think of that.
I had planned on charging all of my battries the night before, but after asking this question originally and finding that I the best thing for me would be to get a 12V DC power supply as Jim, I kind was looking as getting a second set of packs for so I can fly on one pack while recharging the other. Man, I have not even got to the field to begin with an instructor yet (too cold ), and this stuff is getting expensive.

RE: Did I Do Something Wrong....
 

The best way to charge large batteries at the field is to use your car battery. Keep an eye on your car batt voltage and start it up every so often to keep it from getting too low. If your field has 120V outlet, then get a good 12V power supply and use it (that's what I do at a couple of the fields I go to).

This is a great power supply, I got 2 of them on sale a couple weeks ago for $35 each and free shipping! Looks like they are back up to $70, but it's still the best value per Amp output I've seen for a 12v supply:

http://www.hobbypeople.net/gallery/158301.asp

RE: Did I Do Something Wrong....
 

You do have lots of choices. The easiest and cheapest is to pop your hood, attach the charger to the truck battery and charge. Yeah, I would start the truck after a couple of charges to make sure the battery is ok. The generator is a viable alternative. I don't think charging 3600 mAh batteries is going to strain the truck battery, but better safe than sorry. Sending DC to an inverter to convert to AC that powers a DC power supply for your charger seems a little complicated. I usually try to take the simple route but you need to do what you feel comfortable with.

Depending upon how often you want to fly you probably need two or three sets of batteries. That way, one set is always charging and you can fly often. An alternative is to get LiPo's which will charge more quickly (45 min - 1 hr), or A123 which charge very quickly (15 min), but you purchase convenience and speed with $$$. Maybe that's best left for later when you get more deeply into the hobby.

RE: Did I Do Something Wrong....
 

Thanks phk abd Jim, I guess the best thing to do is just use the truck battery at the field and get myself a couple of sets of batteries and rotate through charging and flying them. That 12V DC power is a good one, but man there goes another $70. Not to mention the Electrifly 3600's are $50 per pack and I need two for a flight. So, if I only get one extra set plus the charger I am looking at $170 more even bothing to head to the field. Well, like they say, "The only difference between men and boys is the price of thier toys".

RE: Did I Do Something Wrong....
 

I have to ask. Why convert 12v DC on the truck to 110v AC and then hook it back thru a 12v DC power supply? Why have to pop the hood and hook up to the battery either? Couldn't you just get a cigarette lighter plug adapter at Radio shack and solder on an extension to banana plugs for the charger?

Just asking?

RE: Did I Do Something Wrong....
 

If that will work, it would be easier and cost effective. My soldering skills are also in newbie form, but I could get it. Has anyone done this before.

RE: Did I Do Something Wrong....
 

The cigarette lighter method would be fine for NiMh batteries, but not a good habit to get into if you get LiPos... One guy in our club burned down his car and did $20,000 worth of damage to the interior trying to top off a small LiPo with a cigarette lighter charger.

RE: Did I Do Something Wrong....
 

The cigarette lighter plug will probably put out enough Amps for your charger (probably good for 20A+), although the "auxiliary" sockets in some vehicles are only fused for ~10A (they're not meant for a cig lighter, just 12VDC accessories). Most vehicles switch the power to the sockets off with the ignition/accessory switch, so you may have to leave your keys in the car to keep the sockets powered up.

As mentioned above, be sure to have a safe surface to put the batteries & charger on in case they overheat, puff, or catch fire. It would be best to have everthing outside the vehicle, on the ground or other safe surface.