12volt filed battery?

techguy

Hello,
where will i get a cheap 12v battery to power my starter and pro peak super 12.It must have a decent amount of capacity. And what do you other fliers use or do you all just use the ones in from the model shops?are these reasonably priced or can i get cheaper alternatives somewhere else at a fraction of the price?

Hakko

coolwings

Most model fliers (flying glowfuel models) are using a 12 volt 7 (amp hour sealed gel cell to power power panels, in flight boxes, glow start leads, fuel pumps, and starter motors.
This is similar to the lead acid cell used in lawnmowers, quad riders and the like, but being gel instead of lead acid technology, it can't spill if turned over, and can usually tolerate harder use.
I am using gel cell but the larger size of 18 amp hours. It is hardly ever used to start glow engines, they flick start for me, and my glowstart is nicaded with no wires, my fuel pump a rotary hand pump, just purely for powering an electric charger for high power electric models.
Which one is best for you depends on how hard you plan to use it, and how strong you are...they weigh a lot
What do you use the pro peak for charging ?

techguy

Where will i get a good value field battery setup inc charger and whats the most I should pay?I was checking a few appliences @ home there and noticed a 6v(4.2AH) GASTON battery (which looks the same as the 12v cells you were on about)in a handheld vacuum that was bought including charger in LIDL for €15. If I got two of these and connected them in series would they be as good as a normal 12 volt? Would this work out the same as in the hobby shop for the battery?
Im using the pro peak for charging my 700mah 4.6v flight batteries and 700mah tx nicads.In your opinion is it a good charger Its new and i have only used it once?Would you be able to point me to any good guides on fast charging nicads and nimhs?

Thanks
Hakko

coolwings

hakko1872003 wrote:

....I was checking a few appliences @ home there and noticed a 6v(4.2AH) GASTON battery (which looks the same as the 12v cells you were on about).... If I got two of these and connected them in series would they be as good as a normal 12 volt? Would this work out the same as in the hobby shop for the battery? ...

Not really, but they will do for a while.
You see, if you put 2 of these in series, you do indeed get a 12V cell. BUT your cell is 4.2 Ah so if max drawdown is 12-15% of capacity, then you can draw (theroetically) 4.2 x .15 = .63 amps. not much. The 7 Ah 12V battery fares better 7 x .15 = 1.05 amps.
Now I don't know how many amps my starter motor pulls, but let's guess 30 amps...so the 7Ah battery takes a beating, and lasts just 2 years if used a lot. Your battery gives the same and will "die" a lot sooner. Likely it won't even give so many amps, and when you switch the starter motor on, the voltage falls so your starter motor will revolve slower. I don't know how much, but there will be a difference.
Why don't you try it and see if it's good enough to stick with.

hakko1872003 wrote:

....Im using the pro peak for charging my 700mah 4.6v flight batteries and 700mah tx nicads.In your opinion is it a good charger Its new and i have only used it once?Would you be able to point me to any good guides on fast charging nicads and nimhs? Thanks Hakko

I have not used the Pro Peak but they are OK.
Does the manual give info on safe charging?
Main advice - don't charge AA type nicads faster than 1/2 hour or at a higher charge rate of 2 x capacity. eg if they are 700 mAh AAs then 1.4 amps is going to push them to the limit. Say use 1 amp max charge rate. Only the C type nicads can charge faster.
The best C nicads can charge at 4 x capacity, eg for a 700 mAh (it doesnt exist they are all more than that) you would use 4 x 700 = 2.8 amps for a 15 minute charge, but you would have to monitor the servo plug temperature ... it is only designed for up to 2 amps. The steel pin type might heat up, and allow the plastic to distort making for worse fit later . I have abused the gold pin type with no problems at 3 + amp charges.

Capt'n Midnight

sealed lead acid batteries are usually designed for capacity rather than current eg: for UPS's and things where they are designed to drop down to 20% left - taking too much current is something they don't like doing. So the bigger the battery the better eg: - 15Ah would be less strained than 7Ah

wet batteries like in your car are designed for starting current (cranking power) rather than for storage and aren't designed for deep discharge.

Anyone any idea where to get 12V 7Ah batteries in Dublin - need 8 or so to get a UPS up and running and I've seen prices as low as $9.99 on the interweb but at 6 Lbs each delivery would be a killer.

LIDL still have some chargers with 8x AA's 2000mAh NiMH's - this charger will fast charge 4 batteries in 3 hours or 2 batteries in 1.5 hours and has a cigarette lighter adaptor.

coolwings

You could start with the links here ...
http://www.boards.ie/vbulletin/showthread.php?t=199335