New to park flying...
#1
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New to park flying...
And my question is if it makes sense to get 2 battery packs and a lesser-expensive slow charger, or one battery pack and a more expensive fast charger?
I just picked up a GWS Pico-F (the red baron one) and radio and all the goodies. I got one battery pack and the faster charger. On my way back to work, I was thinking 2 battery packs and the slower charger made sense as I could be charging one while flying (and it's cheaper).
Any thoughts?
-pete
I just picked up a GWS Pico-F (the red baron one) and radio and all the goodies. I got one battery pack and the faster charger. On my way back to work, I was thinking 2 battery packs and the slower charger made sense as I could be charging one while flying (and it's cheaper).
Any thoughts?
-pete
#2
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New to park flying...
Slow Chargers usually means trickle charger, ie. about 12 hours to charge a battery pack.
Fast Chargers usually charge at a rate of about 10x, or 10 times as much milliamp hours as the battery pack, for a much shorter time span. Anything I charge I feel for heat about every 15-25 minutes. If you got a "wall wart" type charger do not charge a battery pack you have flown, for as long as you would a DEAD battery pack. It only needs about 50% to 75% as long a charge on a wall wart type charger, as when it was completely dead, brand new.
More battery packs, mean more fun, especially if you have to drive to the flying field. I used 3 pacs when flying a Firebird, 4 packs when flying a Firebird XL, and 4 Packs when flying a Wattage Mini Max.
Your motor on the Pico-F will not get too hot to go from one pack to another in this cold weather. Hot days you may want to change packs slowly, so the motor and ESC cool down. Happy flying, and you made a good choice![img]i/expressions/face-icon-small-happy.gif[/img]
Fast Chargers usually charge at a rate of about 10x, or 10 times as much milliamp hours as the battery pack, for a much shorter time span. Anything I charge I feel for heat about every 15-25 minutes. If you got a "wall wart" type charger do not charge a battery pack you have flown, for as long as you would a DEAD battery pack. It only needs about 50% to 75% as long a charge on a wall wart type charger, as when it was completely dead, brand new.
More battery packs, mean more fun, especially if you have to drive to the flying field. I used 3 pacs when flying a Firebird, 4 packs when flying a Firebird XL, and 4 Packs when flying a Wattage Mini Max.
Your motor on the Pico-F will not get too hot to go from one pack to another in this cold weather. Hot days you may want to change packs slowly, so the motor and ESC cool down. Happy flying, and you made a good choice![img]i/expressions/face-icon-small-happy.gif[/img]
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New to park flying...
One minor correction...
Charge rate is expressed as a multiple of "C", the capacity of a pack.
C/10 is a trickle charge. For a 500 mAh pack this is 50 mA, and takes 15 hours or so.
A fast charge will often be 2C or 4C (1A or 2A for a 500 mAh pack), and should finish within half an hour or so. Chargers this fast should be peak detecting or they will overcharge the battery.
Don't charge at 10C, that's way to high! (I think you had that mixed up with C/10...)
Charge rate is expressed as a multiple of "C", the capacity of a pack.
C/10 is a trickle charge. For a 500 mAh pack this is 50 mA, and takes 15 hours or so.
A fast charge will often be 2C or 4C (1A or 2A for a 500 mAh pack), and should finish within half an hour or so. Chargers this fast should be peak detecting or they will overcharge the battery.
Don't charge at 10C, that's way to high! (I think you had that mixed up with C/10...)
#4
New to park flying...
I have been flying my Lite stick (Wattage) and I think it is the same as the Pico Stick. I am using a 250mah 7 cell AAA nimh pack in it. It has been the best battery so far. I have tried a whole bunch of nicd packs that did not last long enough or were to heavy. To charge them I use the micro peak charger from Dymond Model Sports. You can find it on sale for $25.00. It is ment for smaller packs, it charges at .3, .5 or 1.0 amps. So with the cost of this charger you can have several batteys and a couple of chargers too.
If the wind would go down I could tell you how long it flys.
Dru.
If the wind would go down I could tell you how long it flys.
Dru.
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Some general small pack observations.
For the smaller Nmh cells it is best to not charge greater than 2x...ie I usually run 300 nmh cells, and using the above mentioned charger ( VERY nice charger for small packs BTW)I charge at .5 amps. Takes about 20 minutes as the pack is usually not compleatly dischaged. (10X will spoke the pack almost instantly) If you charger greater than this, the life of the pack will be very short.
I've also noticed that these small nmh packs, even when treated gently, don't seem to have the life of their niCad counterparts. My 300mah Nmh packs last about 9 months, and I have a few 150-300 mah Nicad packs that I've had for years ( and I work them a lot harder).
Another thing that I noticed is that if the nmh cells sit for a while, the first use is very short. Just rently I cycled 2 of my 300 Nmh packs that sat for about 2 weeks, and after a 16 hour c/10 charge, they showed 4 & 8 mah capacity [img]i/expressions/face-icon-small-sad.gif[/img] The second cycle showed 320 - 318 mah capacity. In the winter ( we got about 18" of snow yesterday/lastnight) when I only fly in a golf dome once ever 2 weeks, I routinly cycle my packs a few days before... If not the first flight is VERY short; less than 2 minutes. I routinly get 17-20 minutes on my 300mah 8 cell packs on a Dusk Stick and MM Cessna.
I'v also found that the capacity seems to last longer ( ie the packs hold their rated capacity over a longer period of time ) if I do a c/10 charge about ever 10 cycles no matter how long they sit.
Later
#6
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Some general small pack observations.
Dave, Things I've read concur with your thoughts that Ni Cad last longer, and Nimh loose capacity, unless you 'wake them up " with a cycle first. ALSO 've read that you can count on the NiCad giving its capacity longer, whereas the Nimh drops off in output , stretching out the "less than full power" time longer.
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Some general small pack observations.
Yep, you need to wake them up if they've slept a while [img]i/expressions/face-icon-small-smile.gif[/img] Also, even with proper treatment, for me anyway, they just don't seem to last as long. After about 9 months my 300 mah pack cycle out to about 120mah. This is treating them with some respect [img]i/expressions/face-icon-small-smile.gif[/img] When I was treating them like my Nicads, they lasted a few cycles [img]i/expressions/face-icon-small-sad.gif[/img] I have Nicad packs from 1998 when I got back into electric that still work great, and I abuse them.
As far as power the way you described... I don't much notice this with the smaller packs ( but it is there), but with the mid-size packs this is very true. What I did notice, despite the discharge curves I've seen, the Nmh cells I use fall off rather flat, as opposed to my Nicads which have the typical "double" knee.
Example:
In a not so scientific test I did last fall. Testing was all done the same evening in DEAD air.
Plane Skimmer 400 DD 6x3 prop.
8 cell 1000mah Nmh pack. 32 watts fresh off the charger. Lathargic climb at best for about 3 minutes. After that full throttle is required to sustain level flight. Landed in 11:30 ish. BEC didn't kick in at this time, but the plane landed even with full throttle. Motor ran for about 3-4 more minutes after I landed.
7 Cell 600 AE pack. high 80 watts hot off charger. 45 degree climb out. Easily cruise around under half throttle. Also did some mild aeros. flight time: 11:30 something when BEC kicked in. Took about 20-30 more seconds to land.
8 cell 600AE pack. Low 90 watts HOC. it performed around the same as the 7 cell pack. More power, but a little more weight.
Time to charge less than 20 minutes for the Nmh cells. 1 hour for the NMH. If I even tried to charge the NMH at 1.5x they got too hot for my likeing. Some say that the NMH cells don't develope any real power untill about 10-20 cycles. The above pack had consistant "performace" even well after 40-50 cycles.
These are "old technology" nmh ( last years [img]i/expressions/face-icon-small-smile.gif[/img] ) apparently the newer ones have much lower internal resistance ( the real cultript here) and some even have lower IR than the equivelnt Nicad. I haven't tried any of these packs, but they look very promissing.
As far as power the way you described... I don't much notice this with the smaller packs ( but it is there), but with the mid-size packs this is very true. What I did notice, despite the discharge curves I've seen, the Nmh cells I use fall off rather flat, as opposed to my Nicads which have the typical "double" knee.
Example:
In a not so scientific test I did last fall. Testing was all done the same evening in DEAD air.
Plane Skimmer 400 DD 6x3 prop.
8 cell 1000mah Nmh pack. 32 watts fresh off the charger. Lathargic climb at best for about 3 minutes. After that full throttle is required to sustain level flight. Landed in 11:30 ish. BEC didn't kick in at this time, but the plane landed even with full throttle. Motor ran for about 3-4 more minutes after I landed.
7 Cell 600 AE pack. high 80 watts hot off charger. 45 degree climb out. Easily cruise around under half throttle. Also did some mild aeros. flight time: 11:30 something when BEC kicked in. Took about 20-30 more seconds to land.
8 cell 600AE pack. Low 90 watts HOC. it performed around the same as the 7 cell pack. More power, but a little more weight.
Time to charge less than 20 minutes for the Nmh cells. 1 hour for the NMH. If I even tried to charge the NMH at 1.5x they got too hot for my likeing. Some say that the NMH cells don't develope any real power untill about 10-20 cycles. The above pack had consistant "performace" even well after 40-50 cycles.
These are "old technology" nmh ( last years [img]i/expressions/face-icon-small-smile.gif[/img] ) apparently the newer ones have much lower internal resistance ( the real cultript here) and some even have lower IR than the equivelnt Nicad. I haven't tried any of these packs, but they look very promissing.
#8
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Some general small pack observations.
Peter; what did you decide to do? Do you fly over by Streetsburough Ohio? I went up there for an electric fly-in on a cold, windy day. Is it pretty far from you?[img]i/expressions/face-icon-small-confused.gif[/img]