I've been looking at a combo 12V Battery, with 7 mAh and it comes with a wall charger so i'll be able to charge the thing over night .... i'm just wondering if this battery will have enough juice to not only charge my 4.8 rcvr pack and 9.6 tx pack, but so i can use the electric starter a few times too.... any suggestions would be most helpful, thanks!!!

I have one of those sealed gel type batterys you are talking about and i only need to charge it once every couple of week's i use the battery to charge my RX and TX packs on the way to the field as i normally go spur of the moment and still have plenty of charge to use the starter lots. I presume you are talking about using a fast charger like the supernova or triton charger both of these are ideal as i can charge my RX and TX in an hour each from flat but i would not reccomend charging over 1c with the RX and TX packs, also make sure that you charge direct to the packs not through switches or the TX charge point as i'm not sure how much current they can handle.

I have a Hangar-9 Double Vision charger that is directly compatible with my TX and RX. I just wanted to make sure that that size, 7 mAh, was going to be enough for a day of charging, starting, and flying.

Actually, it's probably 7 Ah (or amp-hour). That's 7,000 mAh. That's probably enough to do a complete recharge on a set of TX and RX batteries, along with a full day of starting with an electric starter, along with lighting a glow plug. I am using a 7 Ah gel cell battery in my flight box, and I have taken it out for two half days of flying inbetween recharges...although I admittedly don't use it to recharge flight batteries.

The short answer: yes, it's fine.

Yes as MSabol said it is 7 Ah and it is suitable for a few recharges plus starts at least as i only charge mine once every couple of weeks

Go to Radio Shack and get a "cigarrette lighter" adapter. Cut one end off, then add connectors like Sermos or Deans to the end. Add the matching connector to your charger, then you can plug it into the cigarrette lighter on your way to the field.

By using connectors you can also put a matching set on your alligator clips and still use it with a 12 volt battery.

Then buy a pair of 6 volt RC car battery packs and wire them in series. You can then attach them to your starter and be "portable". Of course this will require a manual fuel pump and glow igniter with a battery, but you also get rid of all those cords, and you won't need a power panel.

The 14.4 volts supplied by the 2 "car" packs will provide a bit of a boost to your starter, yet will not harm it. (As long as you don't spin it over for 5 minutes at a time.)

If you have a charger capable of charging 12 cells, you can also charge your "starter" pack on the way to the field.

I've been set up like this for a while now, and I can leave everything in the vehicle for days at a time. Never have to bring anything into the house for charging. (One of my 12 volt chargers can also charge my glow igniter.)
Dennis-

There are some good ideas there DB in fact i quite like that setup myself, as my power panel as started to fail on me i think i will take a trip over to maplins today. Cheers

I use a digi pulse 6 station charger for my transmitter and receiver batteries. It can be programmed to the correct mah level and then goes automatically into a trickle after charging. For cycling my batteries I use the Hangar 9 "sure cycle" and do this about once a month during flying season. For the 12v battery, I have a product called 'battery tender' and it works great. It charges the 12v battery up to capacity then automatically goes into a trickle charge. The wall chargers that are common can overcharge the 12v battery and greatly reduce its lifespan. I know this does add expense to what you are needing, but it does save on battery costs over time.

BTW: You can find the battery tender by just doing a search on the internet. I ordered mine over the phone and received it in just a few days.

http://www.hughesrc.com/

I found the website and added the link for you. I have the JR. size of charger.

I am not sure why you wouldn't just put the Tx. and Rx. batterys on the over night charger before going to the field?!? Some batterys aren't rated for quick charging and will not last long if you fast charge them all the time. [8D]

Actually, a;though you have a valid concern, it is misguided. You do more damage by doing an overnight charge (8 hrs or so) on cells that need only 4 hrs of charging (75% full....). From empty, "standard" cells (the ones that come standard with most TX/RX bundles - 600mAh) need 16 hrs of charge approx. Basically, the wall-wart chargers are designed as trickle chargers, and perpetually trickle charge at about 40mA.

Anyone who has charging/cycling issues should read http://www.rcbatteryclinic.com/

In fact, everyone should read http://www.rcbatteryclinic.com/

It all makes so much sense then, and, Fastsky, you will then willingly retract your suggestion.... ;-)

gus

While most of what you say is true, this most definitely is not. Wall warts are C/10 chargers NOT trickle chargers. A trickle charge is about C/100 and can be left indefinitely without damaging a pack, while a C/10 charge rate will eventually ruin a pack.

I see this mistake made a LOT, and want to do my part to prevent others from "learning" wrong info.
Dennis-

We can all stop the 'arguments' by buying a GP Triton charger ... hehehe ... it will settle all your battery problems! Now ... I better go get myself one! I discharge my NiCads after a couple of charges and for NiMH you just charge her up. Never used an electric starter so my 7mA battery will last for over a month.

I also fly electric and have a Dymond Super Turbo, Triton, SuperBrain 959, GWS MC 2002 and a Schulz. I charge all my batts whether
they are nicad, nimh, li-ion, lipoly gel cell etc. on them. RX and TX packs never over 1C. I only use my 12 volt gel cell in my field box for
hobbico starter. I do have a glow igniter that is used from the field box but generally use a hot shot portable. I have found that the less wires you have hanging from the field box near a moving prop, the better off you are!!!!

Dave...

Gus, Yes you don't want to be overcharging the batterys. However since it is impossible to know how much charge is left in the receiver batterys after a days flying the easiest way to make sure you have a charge for the next day is to put them on a C/10 charger(140ma rate for 1400 mah pack) and then remove the charger before heading to the field. This may add a few extra hours more charge to the pack that isn't needed but at this rate and charge time won't hurt anything. If you leave the same batterys in the same plane it can be checked how much is taken out of the battery but I have different planes and packs so its hard to keep track of. I have several battery packs and check them a few times a year with a Sirius Super Test just to make sure nothing is going bad. I also run "Hobbico Volt Watch" in most of my planes. [8D]