ReneT

I picked up a RC airplane field box and it did not have a 12 volt battery with it. I went to BatteriesAmerica.com and they have several different size batteries. Some of them the physical size is the same but the Ah increases. http://www.batteriesamerica.com/newpage4.htm Should I get the largest one I can fit in the space with the highest Ah or would one with a lower Ah work almost just as good. Would a 7AH work just as good as a 9AH for what I'll be doing.
I was looking at the UB1270, UB1280 or the UB1290. Thanks everyone.

PS: What I the best source for this style battery?

init4fun

You need to define the use of the battery before you can talk capacity . Will you be using this battery to power an electric starter for glow or gas engines ? Will you be lighting glowplugs and or charging on board batteries ? Or maybe flying electric and using it to charge up LIPOs ?

Generally speaking , and within reason of being able to carry it from the car to the flightline , the bigger the better especially if your doing more than one of the above listed things with it during each flying session . Other than the weight of carrying a big battery I've never heard anyone complain their flight box battery was too big , but you bet I've seen complaints about em being too small !

ReneT

I will be powering a electric starter and a fuel transfer pump. The glow plug igniter will be portable and charged at home.

kmeyers

Go with new tech. We "new tech guys" use a small 4s lipo or 3s. Lead acid is so last decade. As far as which, here is what I recommended once.

http://www.hobbyking.com/hobbyking/s...arehouse_.html

These are 5 bucks 1100mah Life 2s1p. Two with a Y connector will out perform the gell cell with over ten amps @ 13.2 volts (for 11 minutes but your stuff won't draw that much so you won't run out that quick). The weight is 130 grams for LiFe vs 2600 grams (that's 1/20th over 5 lbs).

Me though I wouldn't spend any money. I would use two old Lipo packs that were for some foamies no longer in my inventory. The old 4s pack I am using needs recharge twice a year! Also spins my starter so hard practically rips the starter out of my hand.

Also Lipo's have more capacity for weight then Life's So a 20c 4s Lipo pack with ~2200 mah would work great and are sourced cheap all over.

link for 3s

http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html

link for 4s

http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html


my .02

ReneT

Thanks for the reply but you see, I've always been a mechanical type person. I barely do electricity so I wouldn't know where to start to connect something like this. The batteries I'm looking at are in the range of 7AH to 10AH and your batteries are rated in MAH. All Greek to me. In other words, I don't understand.

init4fun

Rene , Kmeyers' suggestion is how some do it , but there are still plenty of folks using the lead acid field box battery . In fact , for someone with not a lot of electrical know how , the LIPO suggestion is ill advised , you'll have enough to do just learning the basics of flying and the LIPO batteries are not very forgiving to beginner mistakes . Were you flying electric powered planes LIPO know how would be of utmost importance , but since your flying Glow engine powered and LIPO isn't really needed for that , Go with what your comfortable with for now to get into the air , and then learn the new technologies at your own pace .

PS , I would strongly suggest checking into the customer service record of any on line retailer that folks here or anywhere else may suggest . Some are better than others and the smart money would be to do a search of that retailer's name and note the ratio of good VS bad experiences before deciding who to trust with your money .

init4fun

PS , I brought this post here from your other thread to mention ;

If your radio control equipment is 15 years old , it will all still be fine to use except for the batteries , the transmitter and receiver/servo batteries will need to be replaced to ensure you have no in flight failures . Your system is 72 MHZ and not 2.4 GHZ right ? If your not sure , 72 MHZ has a 3 foot (ish) long metal antenna on the TX where 2.4 GHZ has a small 7 or 8 inch plastic antenna . At 15 years old my guess would be that it's 72 MHZ which is still legal to use , subject to following the club's frequency control protocol . If your stuff was closer to 25 or so years old you would have possibly had an issue with the old "wide band" 72 MHZ vs the new "narrow band" 72 MHZ , but at only 15 years old it will be the newer 72 MHZ and still plenty useable .

Oh , and , your club will likely set you up with a pilot who trains new flyers . There will be two things they will likely require you to do . One is to sign up with the FAA for a "UAS operators registration" , this is a present day requirement to fly RC models above 1/2 pound and is unfortunately not optional . The registration costs $5 and is good for i think 3 years . The other thing most clubs will require you to do will be to join the AMA , the Academy of Model Aeronautics , at $75 per year . What this does for the club is that it provides you with an insurance policy to cover if you hit people or property with your plane . This is a club requirement , there is at present no law stating you have to have insurance , but most clubs won't let you fly without it and it really isn't a bad idea to have some coverage just in case something ugly happens . The AMA also advocates for aeromodeling to varying degrees of effectiveness but at present are all we've got with regards to a voice in all of the recent FAA happenings . It may seem a lot , $75 for the AMA , $5 for the FAA , and $50 to $75 average for most club's dues , but getting all the formalities out of the way for either side of $150 is still WAY cheaper than any Golf club membership will ever be , and ya just don't get that great smell of a running glow engine on a Golf course

Rodney

If you go with the Pb batteries, just remember to NEVER discharge below 11.9 volts under load else the batteries will have a short life. Also, if sealed batteries, charge at 0.1C with constant voltage/limited current charger, never fast charge. If you obey these two rules, your batteries will last much longer than if abused. It is not advised to use these smaller mah batteries for charging flight batteries at the field as they are too limited in capacity to be really usefull.

ReneT

Thanks for your reply. I will stay with the standard lead sealed battery for now. I was just wondering what size. 7AH or up to 12AH. Like I said earlier, I'm only running the electric starter and the fuel transfer pump.

ReneT

Yes it is 72MHZ. I am familiar with joining the AMA. When I first stated to get a little involved 13 years ago, I did join so it may be just a matter of renewing my membership now. 3 months ago, I spoke the head instructor from the club I'll be joining when I go back to FL next fall. The club allows you to fly with a instructor for free for up to 2 months then I'll have the choice of continuing with the club and joining or leave. The club dues is $100.00 for a newbie and $200.00 the following years. I think they have around 150 members so it's a fairly large club. I believe the runway at this field is 300' ling and it's paved along with the taxi lanes.

ReneT

What is a Pb battery?

Antares100

My Feedback: (12)

A Pb battery is a lead-acid battery, Pb is the elemental designation for lead.

init4fun

Personally I'd go with the biggest one that was comfortable to carry . If the weight difference isn't too great between the 7 and the 12 , get the 12 . A little extra capacity will never hurt . If it is much heavier , and since your likely not starting anything much over .60 size , the 7 will likely do the job fine if fully charged when it gets to the field .

If for $200 your getting a paved runway and club facilities as nice as I've seen some Florida clubs have , then I truly do envy you . I fly off of a sometimes mowed grass field surrounded by woods with no facilities whatsoever for $75 a year . The AMA will reinstate your old AMA number if you call them , I know several folks who took 10 or more year breaks from flying and got their old AMA numbers back with a phonecall to AMA HQ .

PB is the chemical symbol on the periodic table of elements for Lead . Reference to a "PB" battery means a Lead battery .

RC_Fanatic

My Feedback: (1)

I use old batteries from my motorcycle. When they seem slow to start the bike, they will still work great in a field box or starter. I've been using one for over two years since I took it out of the bike and it will still fire up an OS 120AX without a problem. A stalled starter will take a lot of current, probably more than a LiPo will take.

ReneT

[QUOTE=init4fun;12214177]

If for $200 your getting a paved runway and club facilities as nice as I've seen some Florida clubs have , then I truly do envy you . I fly off of a sometimes mowed grass field surrounded by woods with no facilities whatsoever for $75 a year . The AMA will reinstate your old AMA number if you call them , I know several folks who took 10 or more year breaks from flying and got their old AMA numbers back with a phonecall to AMA HQ .


QUOTE]

This is their Web Site: http://imperialrcclub.com/

It's actually a 600' paved runway with two 300' cross runways.
Taxiways are also paved leading back to the pits.

Chumley54

That MAH thing isn't hard. YOu are looking at the lead acid battery with a 7AH or 12AH rating. If you are using the MAH, then you are looking at a 7000 or 12000 MAH rating.

To convert to MAH, put 3 zero's on the end. To convert from MAH to AH, take 3 zeros off.

A 12 AH (12000 MAH) lead acid is going to be a lot cheaper than either enough LIPO's to add up to 12000, or a 12000 MAH battery.

Get a good charger for the lead acid battery. A Battery Tender Jr. (made by Deltran) is about $25 on Amazon http://www.amazon.com/Battery-Tender...tery+tender+jr

It will keep the battery charged correctly and extend it's life. I use this on my motorcycle and get 7 + years out of them.

ReneT

Thanks Chumley 54. That really helped.

ToniFrance

Hello..as per my experience with not a lot of electrical know how , the LIPO suggestion is ill advised , you'll have enough to do just learning the basics of flying and the LIPO batteries are not very forgiving to beginner mistakes . Were you flying electric powered planes LIPO know how would be of utmost importance , but since your flying Glow engine powered and LIPO isn't really needed for that , Go with what your comfortable with for now to get into the air , and then learn the new technologies at your own pace .

electronics assembly

warhwk

My Feedback: (3)

I pick up generic lead acid batteries at the local cycle shop for less than $30. I absolutely refuse to use the "Gell Cell" batteries they sell in hobby shops. They barely turn over a .40 even when new.
You can then just use a motorcycle trickle charger to keep the battery topped off, or use the 2A setting overnight with a standard charger. Another free option is if you have any 12v wall warts that are not being used. 500mA - 2A will work fine. Just put some alligator leads on.

JPMacG

My Feedback: (2)

+1

If you don't mind the size and weight, consider a wet lead-acid lawn tractor battery. They have more capacity and more cranking amps than you will ever need, they are inexpensive, and will last 6or 8 years if charged properly.

kmeyers

Low weight and one modern charger purchase that will fill all your needs in the hobby for years.

http://www.hobbyking.com/hobbyking/s...ger_Blue_.html

Here is a great beginner charger. I already gave you links to my battery recommendations.

I have no idea why someone would want to carry 10 pounds of stuff to and from the flight line (the charger stays in the car).

Learning a little about the new batteries won't hurt or cause warts or take anything but a few minutes. Learning is a good thing.

At my field you don't see Lead Acid batteries anymore. You see home made holders or simple straps holding the batteries to the starter.

The charger is computer controlled and does all the work
itself.

You would be very surprised at how few electrons you use in a couple of months of filling, glow igniter and starting.

I don't like typing so I will limit the tech info, just take my word.