how long do receiver batteries last? Should you have more than one when you go to the field? Is it better to have two Flat 4.8V 600mAh or more more MAH battery? Should you get a charger that can be charged using your car battery instead of going back home?

We could spend time re-typing what has been covered on the battery forum more than once. Or even better, you should check out Red Schoefeld's website. NOBODY knows more about the batteries that we use than Red. Spend some time on his website, you won't be sorry.

[link]http://www.rcbatteryclinic.com[/link

Hope this helps

thanx

Now that I look through the website, It gives 2 much information which confused me even more. I just need to know the basics. Sometime's too much information is no good.

NJAIRSTRIKE,
I'm sorry that in 4 minutes you thought there was too much information there. But I'm not one to give advice when there is a BETTER source for that advice. The fact of the matter is that there are is a lot of false information or just plain myths concerning the batteries we use. The info on Red's site goes a long way to removing the false info and busting those myths. IMHO I think that anybody with even a passing interest in this hobby should spend some time on Red's site educating themselves on the batteries we use. It's sad to see somebody lose a $300+ airplane because a $20 battery went bad from neglect.

Just me .02 cents worth

They last until you use up the energy stored in them. This will vary based on the size of plane, flying style, condition of the batteries, how easily the control linkages move, etc. Bottom line, it's not possible for anyone here to answer your question. In case you haven't already heard, you should get a battery tester so you can check the receiver voltage at the field.
I never bring more than one per plane. I find it way too troublesome to remove the wing, pull the battery, wrap a new one in foam and put it back in the plane.
Battteries come in many different shapes and capacities. I have 300 MAH, 600 MAH, 650 MAH, 1350 MAH, and 1650 MAH packs. Each size is appropriate for its intended size. I've never used two receiver packs in one plane. If you need more capacity, get a pack with a higher capacity.
I've managed to get by for years without needing a field charger. I know some people who show up at the field and the first thing they are doing is hooking up their charger. Personally, I think this shows a lack of planning, it's pretty easy to plug in a plane the night before.

One more thing, Red's site has lots of useful information, perhaps you could spend a bit more time there.

I use mainly NiMH batts for RX packs. I get 1000 -1200mAh packs and those will typically last me 5 or more flights (~ 10 mins or so each) in my planes, which have 3-4 Futaba S3004 servos on them (standard BB servos). I don't do 3D or much aerobatic stuff yet, and flying "harder" will run that batts down quicker. I put a 1200mAh NiMH pack in my latest SPAD, and got 9-10 flights (averaging about 8-9 mins each in the air) before my VoltWatch batt meter read in the "low" range. I have a 2200mAh NiMH pack in my Raptor 50 Heli, but that has 5 high torque digital servos and a gyro, so I get 4-5 flights out of that.

I'd say if you're just starting out, and already have a 600mAh NiCd pack, try it and see how many flights you typically get out of it, and upgrade it if you want more. If you're looking to get a pack for your first plane, I'd recommend a 1000-1200mAh NiMH pack. I believe that is a pretty good tradeoff between additional weight and additional capacity. I find I can usually fly until I'm ready to take a break, and I can charge my batts while I BS with the guys at the club!

I'd highly recommend getting a good peak charger for use at home and the field. You will find youself needing to recharge your RX or TX batt at the field sooner or later. You can just hook this charger to your car battery, or most guys get a field box with a 12V sealed lead acid battery inside to power an electric starter, fuel pump, and the charger. Most guys get something like a 7Ah 12V batt for their box, but I've seen 4Ah batts, and I have a 12Ah batt in mine.

Here's a couple of good peak chargers... I have the dual output (two batts at once) MRC SuperBrain 969 Pro, but the single output 959 is half the price and also comes with an AC supply for home use. The Hobbico is a good value on a dual output peak charger, but it has no AC supply, just a 12V DC input...

http://www2.towerhobbies.com/cgi-bin...&I=LXEVC7&P=ML
http://www2.towerhobbies.com/cgi-bin...&I=LXAVN1&P=ML
http://www2.towerhobbies.com/cgi-bin...&I=LXCTZ5&P=ML

I also highly recommend installing one of the VoltWatch batt monitors on you plane(s). I have one on all my RC aircraft, and it makes monitoring/checking your RX batt pack a no brainer... just move both TX sticks around to get all your servos moving and watch the meter to see how low it goes under the load... if you're getting in the "low" range with all the servos going, it's time to charge up before you fly again...

http://www2.towerhobbies.com/cgi-bin...&I=LXMZ56&P=ML
http://www2.towerhobbies.com/cgi-bin...&I=LXHDJ2&P=ML

Hope that helps...

Thank you very much guys.