Flat battery incident - Light, Portable Emergency Battery ?

mistergerf · #1 08-13-2007, 11:36 AM

Had a great weekend in the LA area, until I went to flip on the master on Sunday ready for the trip home to HAF. The last thing I did on Friday night when we parked was turn on the master to record the flight numbers in the log book ... yeah, you guessed it ...

Long story short ... it was remarkably easy to hand prop the engine and get it going (thanks to the single impulse coupled mag). That is if you have enough juice in the battery to run the boost pump long enough to get the fuel injectors wet. That meant the battery had to come out and go visit with the maintenance facility for an hour.

I wish I had a light 12V reserve battery in my tool kit that could supply 6 or 7 amps for a minute or so just to get the boost pump running and to energize the Lightspeed ignition. I have an Aux power jack in the panel.

Anyone got any suggestions on such a battery ? I've heard that battery technologies have leapt forward in the recent years.

The PC680 battery doesn't seem to hold full voltage since the incident - is there an issue with running these batteries dead ?

(Observations: If you have the AFP injection system, you need someone in the left seat to close the purge valve once she fires. I'll think twice before removing my single impulse coupled mag in favor of a second Lightspeed. Parking brake valves are good !! Time for an "Overnight Parking Checklist".)

g

rv6ejguy · #2 08-13-2007, 11:58 AM

PowerSonic makes some small batteries that I've used over the years for various things including backups for both my RV projects. Cheap, robust and can be side mounted. http://www.power-sonic.com/index.php?id=31&gr_id=40

A 1270 would probably do the trick.

mistergerf · #3 08-13-2007, 12:22 PM

Thanks, that's interesting ! I recall a type of battery that consisted of cells of rolled up film that was capable of giving a discharge rate similar to a lead/acid battery, can't remember the name of it.

dan · #4 08-13-2007, 12:35 PM

TMF = thin metal film. I don't know much about it, but it sounds like what you're talkin' about.

mistergerf · #5 08-13-2007, 12:45 PM

That was it !

http://www.boldertmf.com/

I don't see any distributors/retailers in the US though ...

g

grjtucson · #6 08-13-2007, 02:29 PM

This might do it. Useless for what they sell them for, but probably close to what you need. It's only 5 amps, but the price and weight are reasonable:

Wagan-2045-SelfCharge-Auto-Jumper

George

mistergerf · #7 08-13-2007, 02:53 PM

Heck for 28 bucks its worth it just to play around and see how effective it would be. Thx George.

airguy · #8 08-13-2007, 03:08 PM

Here's a possibility - and compatible with aerobatics as well....

http://www2.towerhobbies.com/cgi-bin...?&I=LG2819&P=1

gasman · #9 08-13-2007, 05:01 PM

The PC680 battery doesn't seem to hold full voltage since the incident - is there an issue with running these batteries dead

I did the same thing with my 680. You are right, they don't like to be fully discharged. But mine came back OK this time.

You drained the battery at about 1.5 amps. Now it needs to be charged at 1.5 amps or less. 12.8 volts is fully charged. But they will charge up to about 13.2 volts.

Use a float charger to do this. HARBOR FREIGHT HAS a float charger (#41288) for about $15 or $8 on sale. It makes a great standby charger. It WILL NOT over charge. You can leave it connected any time you are not in the air.
The battery in my Warrior is ten years old. It is a pink GILL vent type battery. When the Piper is not in the air, it is connected to the charger. It does not fly as often as the RV6A but the battery is always ready!