Thorp Air Command - T18.net

If anyone needs a PC-680 battery, Amazon has them for $105.00/no tax/free shipping.

RB

Has anybody installed a battery on the firewall. With some the new batteries I think it would be possible on the T-18. I would appreciate any input.

Jim Borg (n180rg)

MLMP has a battery on the firewall. (Fixed pitch wooden prop.)

Bada Bing, Bada Boom. 13 pound AD prop. I also installed a battery charger lead on the battery so I can plug in a battery charger while at home. No problem with W & B .

RB

Gotta love the smart charger & the PC-680.
Gotta love that DENSO mini alternator, all the guts load in thru the back.
Gotta love home built planes, you can install PC-680s, DENSO mini alternators and any other superior part that is lighter, better, cheaper, lasts longer, is easier to find etc.

I have this battery under the baggage compartment. The battery, alternator, and high torque starter check out but the thing just barely gets the O360 cranking.
I

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http://www.dixiefriedfabrication.com/

Get a helper, and use you Volt Ohm Meter to find out where the high resistance connection is, or if your battery voltage is drawn down too low, indicating a tired battery.
PC-680 batteries are used in VANs RVs extensively. I tend to think you have a problem in an otherwise good system.
I like the auxilliary power connection idea, behind the wing. Lots safer than hand propping.

Another reason I installed the battery on the firewall...shorter lead to the starter and I used a smaller gauge wire. Sounds like something is pulling the battery down ? Bad connection, rust/corrosion. Might even be corrosion inside the sheathed battery lead ?

RB

I use a 35 AH wheelchair battery mounted behind the baggage compartment (for W&B) cranking a an IO-360. No problems. Make sure your connections are good and you are using copper wire, not AL as was tried on some Pipers back in the day. Wire for a run this long needs to be #2 aircraft grade wire. Some folks I know use heavy duty arc welder lead wire.

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Bob Highley
N711SH
SN 835
KLAL

Lou, doesn't your alt put out right at 14v? If not this may be your troubles. When my bird was new the alt would push 14v easily, the skytec would spin the motor easily. Check to see if I am wrong but the 680 needs a mean jolt and I believe 14v is what the thing needs to pack a wallop. I don't see 14v much on my voltmeter anymore and sometimes my starter struggles also and I have a new battery. Dan

Dan: Funny you should say that. Before starting I see about 13 volts on the volt meter. After start I see 14 + on the volt meter and a positive on the Amp meter that gradually goes to just above zero (what I would expect). Volt meter stays above 13.5 + volts for the rest of the day . I could/may have a slight drain ? Too many trons running around ! Kind of like your little lite in the glove box that stays on all the time !

RB

HI Rich,

I like your battery setup. A few questions. Where did you get the bracket for the positive post to the soleniod? How close is it to your mag? Are you concerned with touching it with a wrench while adjusting mags or doing any other work in that area?

Did you only use the top to bolts to attach the mounting bracket and if so is that because of the hinge at the bottom?

To what did you attach the ground cable?

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Matt Smith
Des Moines, IA
55RC

I installed a PC-680 in both my RV4 and RV6X, both firewall mounted. The first one has 1000 hours on it still going strong with it's new owner. The second PC-680 spins my RV-6X's 0-320 Catto prop fast enough to taxi!
Well, not quite.
I also converted a baggage compartment mounted aircraft battery in a IO-540 powered Harmon Rocket to a PC-925. Weighs the same as a Concorde but nearly twice the Cold Cranking Amps. FYI...

Gotta love em!

V/R
Smokey

I have a concord battery just behind the baggage compartment spinning a C/S - I need the weight of the concord for CG - I just replaced my alternator - old one was charging 12.5V at idle and wound up was charging 13.5-7 - not enough it seemed and the battery was pooping out if I let the plane sit for an unusually long 5 or 7 days between flights. New alternator settles in at 14.2V steady within 10 seconds of engine start - both idle and wound up - was worried about the battery life, but put a charger to it one time to a full charge after installing the new alternator and so far four flights with 3-4 days between and the battery cranks over well.

I posted some pics of my battery install in my gallery

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Matt Smith
Des Moines, IA
55RC