Quote:
Originally Posted by RicksterRC
Characterizing a battery is harder than just a volt or ampmeter.
Though I guess you could do it...
There is specialized equipment for this specific purpose.
Early on, someone posted graphs of various batteries, but I don't think I've seen one of the 120mAH vs 130mAH and nothing on the "new 150mAH".
The important characteristics of a battery for a heli are:
1. Weight
2. Capacity (mAH = milli amp hours = energy = how many milliamps can it supply for an hour). Not everyone ends the timing at the point that the heli can no longer fly, so this is always suspect.
3. C rating = power. Higher C gives more punch.
"C" is the rating of the max current a battery can/should put out relative to it's "capacity". A 20C, 120mAH battery can be discharged at 20 times 120mA = 2400mA. Note that you'll get somewhere less than 1/20th an hour out of it.
1/20th hour is only 3 minutes, but you're not always pulling 20C, so it lasts longer.
The fact that we get 5 minutes indicates about 12C average.
Exceeding 20C will cause heat and possible damage.
A 25C 130mAH battery can discharge at 25 * 130mA = 3250.
So while the capacity is only 8% more, the max current is 35% more.
Even when not drawing max current from a battery, those with higher C ratings will lose/waste less energy in heat.
This probably helps offset the increased weight with only 8% more capacity.
The 130's are heavier, but have a noticeably more punch.
Most people report that the extra capacity outweighs the extra weight and they get longer flight times.
When I switch from a "dead" 120 to a fresh 130, I almost always shoot my Corter into the ceiling from the extra punch. Very noticeable (especially after the 120 being low).
Extra punch = If you're dropping fast and punch full throttle, the 130's can keep you from hitting the ground when the 120's wouldn't have been able to.
I think they last longer, though I haven't really timed it.
I put two layers of duct tape on the bottom of my 130's to help prevent damage as they do hit ground when you land (especially when you "land" hard).
I'd like to see a report from someone who has the 150's before I replace all the 130's I have.
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A nice tutorial on our LiPos, RicksterRC. There is more to it than mAh, for sure. FWIW, the two batts I got with my original RTF are the longer ones. I threw in 5 batts when I ordered my BNF and they are shorter than the first two. I've not timed anything or done any precise measurements but I just don't notice enough of a difference that I can recognise between the two. The
only thing that I
think I've noticed are the longer ones seem to 'hang on' through trimming yaw just a
little bit longer. The advantage is being able to escape from doing something stupid on a low LiPo (don't ask) Other than that, the shorter ones seem to keep a great charge and when they're done, they're done.
I'm just trying to get a temporary fix until I order a new tail motor.
