*JCB*

My Feedback: (9)

a few questions...

first: my 12V gel cell battery can only power my starter enough to start my .40 sized plane engine once or twice before i have to use the "bump" method by letting the starter wind up first. is it time for a new battery?? this is after letting it charge for 24hrs

second: what is the life-expectancy of a 12v gel-cell battery??

third: can these batteries be ran in parallel for powering mulitple things for an all-day outing such as power panels and field chargers? or is it even needed, will one battery power a charger and a power panel all day?? I was hoping to get the Hobbico Accu-Cycle Elite Battery Cycler, Hobbico Quick DC Field Charger or Triton, and was concerned that the 12V gel cell puting out 7 amps wouldn't last long powering one of these.

THANKS!!

Flying Geezer

My Feedback: (14)

JCB, you didn't say at what rate you charged the battery. If it was the typical 500 mA wall mole you may have over-charged. An automatic float charger, which shuts off and comes back on automatically, is the best way to maintain a gel cell.

From your description of starting .40 size engines, you must have a battery or starter motor problem. Try your starter on another battery. Process of elimination. Try your battery on another starter. Gel cells can last many years. I know of some that are approaching 10 yrs.

The secret of success is keeping them charged, but not over-charging. It is also bad for most battery types to be drawn down too low. When they get weak on the job, it's time to charge, instead of sucking every last bit of power from them.

As for powering the Hobbico Elite with a 7 Ah gel cell, I would suggest a much larger battery, especially if you are going to use it for your power panel and electric starter.

A large gel cell or deep discharge lead acid battery, like a marine battery would be suitable. Avoid automotive, garden tractor, and motorcycle, type batteries. They are designed for big bursts of power for short periods of time. Deep discharge of these batteries make their lives very short.

I use an 18 Ah sealed lead acid battery for field charging, and 7 Ah gel cells for starters. I get long life from both.

Hope this helps,

Sky 5

I was just looking at a GPS gell cell on eBay, 12v 7 amp hr. It is $7.15 + $7.50 shipping from AZ. I don't have a starter but was wondering how many amps a starter draws. Two starts you say?

rajul

My Feedback: (58)

JCB, you might find this battery tutorial helpful http://www.batterystuff.com/tutorial_battery.html

*JCB*

My Feedback: (9)

Hey Geez, would you recommend using a battery tender on my field battery?? and if so, what kind can i use? would i be able to use the same type that i use on my motorcycle battery?

and thanks for the website rajul...lots of good info

Flying Geezer

My Feedback: (14)

I use the Battery Tender Plus on my larger batteries and the Battery Tender, Jr on the smaller ones. The Jr's are fine on the big battery, but it takes longer to charge.

In fairness, I should say that I sell the Battery Tenders at hughesrc.com., so allow for prejudice.

If you have one for your motorcycle, it will do, if you don't mind moving it around from battery to battery.

Hope this helps,

*JCB*

My Feedback: (9)

ahhh...that's the exact one i use for my motor cycle!! maybe i'll just go pick up another one
thanks so much for your help!

Geistware

My Feedback: (16)

I would say to charge the battery with a constant voltage supply set at 14.5 volts.
Keep power on the battery until the current is below 100ma.
This should show that it is fully charged.
Keep it above 12.8 no-load

Mike in DC

Something is not right. I have a Tower Hobby gel cell 7 amp battery, and it starts my .46 engines many many times between charges. It's several years old, and I probably only charge it once every ten trips to the field. In fact, I've never run it down, I just charge it when it seems like it's been a very long time. Of course, no lead acid battery likes to be run down more than 50% of capacity.

Flying Geezer

My Feedback: (14)

Geistware has a pretty good idea. A 15 volt wall wart rated at 500 to 750 mA, a voltmeter, an ammeter, a sandwich, drink, and a good book, and you're all set. It'll probably cost a little more, but you get to watch! LOL