ORIGINAL:
Now, my question is this. Do most of you electric R/C pilots out there typically have enough batteries on hand to last the day, or do you charge in the field? If you charge in the field, what sort of setups do you use?
Is there typically Electric available at the field?
Do you charge from your Car battery?
Do you have larger batteries you charge your packs from?
Some sort of available alien technology I'm not familiar with?
Thanks for taking the time to read my question.
I usually have 2-3 battery packs that will fit any one of my planes. Normally several planes use the same packs so I don't need a zillion battery packs. I also have 2 chargers with me.
In normally go to the flying field for 4-8 hours at a time so having enough packs for the day was never part of my plan. Having enough packs to handle a reasonable charge rotation is what I look for.
Mostly I fly Lipos these days and most of my planes are flown at 1/2 to 2/3 throttle most of the time. I can get 15 minutes or more of flying time that way.
Many are electric gliders where I make a 30 second to 1 minute run to altitude then I power off and look for thermals. Even if I don't find much lift, I can usually get 8-12 climgs like that so 30 minutes on a pack is common and I can easily go over an hour on a pack.
I you fly a pack, then it goes on a charger.
Fly the second pack, then it goes on the charger. The first pack may be done at that point.
If I have a third pack, I will go up again, or I switch to a plane that uses a different pack.
With NiCds there was a pretty fast turn around. In as little as 20-30 minutes, charging at 2-3C, a pack was ready. However they were heavy and did not last very long.
NiMh you could finish a pack in about 30-40 minutes at 1.5-2C charge rate. They took longer, but for the same weight, they lasted about 40% longer so it was a good balance.
Lipos take 45 minutes to an hour to charge, depending on your charger and the pack. Some of the newer lipo chargers claim to be able to safely charge at up to 3C. That would get lipos back to the charge rate of NiCds. My fastest lipo charger does 1.4C.
So it is a combination of your style of flying, how long you stay and how long your packs last. But I always charge at the field and I typically have two chargers going.
If you are getting the Electristar RTF, then you have a choice of lipos or Nimh. You only reason to go NimH is if you can leverage some of your car batteries and chargers. But those are likely to be 6 cell packs and either te wrong shape or too heavy for the plane.
Based on the recommended packs, the two NiMh packs, together weight 30 ounces. The two Lipo packs weigh about 12.5 ounces. 17.5 onces difference, in a plane is HUGE. Even though the two 2 cell Lipo packs will be slightly lower in voltage, I think you will get better performance on the plane with the lipos due to the lighter weight.
I don't know what the ESC or BEC are rated for but you can likely fit 3 cell lipos in there which will give you GREAT performance compared to the NiMh packs and still probably be 10 ounces lighter. It might be an upgrade for later as the ESC may not be able to handle the 3 cell packs or you might have to change the prop so you don't over amp things. But that is a consideration for later.
Go LIPO
If you get into planes, you will go to lipos or A123 packs eventually. The capacity to weight ratio is just too good not to go there. In cars, it may not matter, but in planes weight is everything.
If you are going to be flying planes of similar size and weight, just get lipos that will fit the current and likely future plane. Then invest in a second charger and a third pack for the next plane.