Thorp Air Command - T18.net

Took the little bird around the patch one last time before she goes in for her condition inspection, I plan to be pretty thorough and confirm that all the SDR's have been done, I also plan on getting rid of weight where I can, like my 27 pound Gill G35, my question is what is the lightest weight battery currently being used in experimental aircraft, is the odyssey PC 680 still the best I believe it weighs 15 pounds,

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John Letkeman
N2562K SN.922
Seminole Tx
(KGNC)

I have used a wheelchair battery for many years. I get 5 to 6 years service out of them. It is about the size of a garden tractor battery. My battery is behind the cargo bay (baggage area) for weight and balance purposes.

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Bob Highley
N711SH
SN 835
KLAL

Good point, I need to check my weight and balance before I go buy a light battery, My Battery is located directly behind the copilot seat

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John Letkeman
N2562K SN.922
Seminole Tx
(KGNC)

I use the PC 680
Cubes

Garden tractor battery from wallyworld lasted 7 years cost 26.00 n it's not heavy, 3 years on the replacement so far.

Lance

PC-680 on the firewall with the 13 pound AD prop . Just replaced current 5 year old PC-680 that stopped holding a charge . BOOM ! Not sure why , but the current PC-680 has a CCA rating of 170 compared to the old one I just replaced that had 220 CCA rating ?

RB

I've used gel-cell batteries from a local supplier that are relatively cheap & have lasted at least 5 years. DEKA builds some batteries that are very comparable to the PC680, are made here in the USA, are also AGM (absorbent glass mat)... and are cheaper. I'm using one in my new project. If you really want the lightest thing going, Lithium is the ticket. I'm not quite ready to jump on that wagon, but if I did Earth-X is the only one I'd trust at this time. They're being used in a lot of homebuilts. They have a built-in BMS (battery management system), which is critical with Lithium. The ETX680 & ETX900 will both fit in a PC680 size box. You will lose about 11# of weight! The ETX680 weighs 4.1# & the 900 is 4.9#. I think the CCA of the 680 is 320! These batteries are really pricey, but there is nothing lighter and more powerful at this time.

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John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

My airplane came with a PC535 on the firewall. It seems small, especially for an O360, but it has lasted over 5years and swings the prop easily. Mind you, there have only been a half dozen engine starts in the last five years.

D

Battery Tender LiFePo
http://www.batterytender.com/Batteries/ ... ttery.html

2.1 lbs - Your battery box may be heavier than the battery ! - cranks even IO 540 fine
Built in balance charging so no special maintenance needed

I guess I should have said that there is nothing lighter & more powerful THAT I WOULD TRUST. I am very cautious about these batteries, with good reason. Bob Nuckolls has done some research into them, and I believe that there is a real lack of accurate needed information available about most of them. Some manufacturers or distributors were unable or unwilling to provide information critical to making an intelligent decision about the safety & true performance of their product. These batteries are probably the wave of the future, but I stand by my statement that Earth-X is the only one I would trust at this time if I needed to lose weight & wanted to spend that much on a battery.

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John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

I just put an Earthx etx680 in the same firewall mount that I had an Odyssey 680 in. The odyssey was getting close to replacement time and wanted to shed some weight due to heavier engine install.

Like John said, it is the only one I would feel safe with as an over voltage is not a good deal with these batteries. Has built in over voltage protection (along with some other protections) and I also have over voltage protection on alternator circuit, in addition to earlier warning from engine monitor. So should be covered for that potential problem.

It really cranks the 340 engine over fast. Better than the odyssey. The lithiums are supposed to have much less discharge when sitting, so will see over time how much better that is over other batteries. Longest sit between starts has been about three weeks and feels like you just charged it. Also supposed to have longer life than most batteries, but only time will tell. Hope so, cause they are expensive.

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Bernie Fried
N18XS

lots of good info guys! thanks for sharing, anyone using this battery? http://www.aerovoltz.net/aerovoltz-12-c ... m-battery/

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John Letkeman
N2562K SN.922
Seminole Tx
(KGNC)

Well it looks like I'll be spending my panel money on an engine rebuild, found metal in my oil screen and decided to remove a cylinder to get a better look, found a cam lobe badly worn and tappet body's spalled, so the Thorp may be down for a while since I don't have a lot of time to work on it lately, at least I have my Starduster to fly in the meantime if it dosnt sell,

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John Letkeman
N2562K SN.922
Seminole Tx
(KGNC)

Can someone tell me what the weight of the Odyssey PC680 is? My research shows 15+ pounds but is this shipping weight or actual weight of battery?

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John Letkeman
N2562K SN.922
Seminole Tx
(KGNC)

website says the battery weighs 15.4 pounds. http://www.odysseybattery.com/extreme_b ... specs.aspx