April 2014-
Q: Any chance of a stick for measuring fuel when the outboard-most tank has fuel, but is not yet full to brim?
The wing gauge is okay for the inboard tank , but tops out at 25 gallons, so if you can see fuel in outboard tank it only indicates you have more than 25 gallons—but no closer figure. It would be nice to have a stick.
Thanks,
Charlie
A: Hi Charles,
I wish I could tell you where you can get a perfectly calibrated gauge for the tanks in your Lance, but I don’t know where to get one.
There are some options for you, though.
1. Make your own. I have one that’s made out of a straight, thin piece of hardwood. It was calibrated by filling the tank in graduated steps (three-gallon or five-gallon steps) starting with an empty tank and the airplane on level ground.
2. Buy a generic 26-gallon fuel gauge from Sporty’s, Chief Aircraft or Aircraft Spruce and Specialty. The cost is around $23.
3. Buy one that’s close from dipstikfuelgauge.com, or use the instructions under “How to tank test” as a guide. The owner of the site may even be able to make you one after you email him the dimensions; it wouldn’t hurt to ask.
Happy flying.
Q: Steve,
The battery in my Cherokee seems to be getting weaker. It’s three years old and my mechanic wants me to replace it with the same kind. It’s one that has to have water added after the caps have been removed.
I know that batteries contain acid and I noticed that the battery in my new car doesn’t have removable caps. To me that means the acid inside can’t leak out, which is a good thing. Are there any airplane batteries that are leak proof?
If a leak proof battery is available, can I just swap the old battery with one of the new ones that doesn’t leak?
—Battery Bob
A: Dear Bob,
The original batteries in all legacy (pre-1994) light aircraft are what are called flooded cell batteries. There are some distinct disadvantages to using flooded cell batteries. For one, they are full of a liquid electrolyte that’s dilute sulfuric acid; secondly, they expel explosive gases laden with drops of sulfuric acid.
For these reasons flooded cell batteries are mounted inside metal (or plastic) boxes featuring airflow inlets and exhausts designed to pressurize the boxes and push the destructive gases/droplets overboard. Flooded cell batteries have been produced for aircraft use for at least 60 years.
Watchful and careful maintenance is vitally important when a flooded cell battery is installed. The venting system must be clear and open, all electrolyte spills must be neutralized with a solution of baking soda and water and the battery box and surrounding area must be repainted regularly with acid proof paint.
The most powerful light aircraft batteries are known as starved electrolyte or recombinant gas (RG) batteries. There are three distinct advantages to RG batteries. First, they never leak; therefore, if it were legal to do so, one could be mounted in any position without a battery box. Second, the self-discharge rate is a fraction of the best flooded cell battery.
Lastly, RG batteries have very low internal resistance which translates into remarkable cranking ability when compared to flooded cell batteries. For instance, one measure of battery power is its cold cranking amps (CCA) rating. This rating is determined by applying a load for 60 seconds with the battery at 0 degrees F. A typical 35 size flooded cell battery is rated at 250 CCA.
Concorde Battery Corp. discontinued its flooded cell line (CB-35A and CB-35AXC) on June 1, 2013. It now sells the RG-35A and RG-35AXC. The Concorde RG-35A is rated at 390 CCA and the RG-35 AXC has a 440 CCA rating.
Skip Koss, technical expert at Concorde, told me that comparing a Concorde RG battery to a flooded cell battery is like comparing apples and oranges. Koss was exaggerating a little when he said, “The RG battery has so much power, it’ll spin the prop fast enough to taxi.”
Gill—the pink battery—is the manufacturer of flooded cell batteries today. If you’re a day VFR flyer that lives in a temperate climate, buying a new Gill flooded cell battery to replace the one you have is the least expensive option and will probably provide three years of service. I’ve heard owners brag of five years’ service, but proper maintenance is essential for this kind of performance.
Replacement of your flooded cell battery is easy. Order it, and when it comes, fill it with electrolyte and apply the initial charge in accordance with the instructions. Take the old one out and slide in the new one. The price for a Gill G-35 is around $200.
Installing one of the Concorde RG batteries will cost between $255 and $270, and since it’s not original equipment in your airplane it will have to be installed in accordance with the provisions in a Concorde STC.
The STC approval for installation doesn’t cost anything; all that’s required is to contact Concorde, fill out the STC Information Request form they send, and return it. Within a very short time Concorde will send back its License for Use of STC (it was in my email inbox within hours).
Your mechanic will have to submit an FAA Form 337 (Major Repair and Alteration) for the change and since the Concorde RG battery weighs five pounds more than the Gill battery you’re replacing (32 pounds versus 27 pounds), you’ll need to update the weight and balance computation.
Koss told me that the only battery charger/maintainer endorsed by Concorde for its RG batteries is the BatteryMinder 12248-AA-S5 unit. According to Koss, a Concorde RG battery will last forever if it’s always connected to the BatteryMinder unit between flights. Make sure to use the S5 BatteryMinder; other BatteryMinder units will damage the RG battery.
If you decide to go RG you’ll have to jump through some hoops (STC; weight and balance update; the battery box might need a very slight modification) and spend more money (approximately $75 more for the battery and $190 for the BatteryMinder) but in return you’ll get a very powerful battery that should remain serviceable for a long time.
Whether you choose another flooded cell replacement or decide to change to the RG type, you have two excellent choices and just need to take into account your budget.
Happy flying.
Know your FAR/AIM and check with your mechanic before starting any work.
Steve Ells has been an A&P/IA for 39 years and is a commercial pilot with instrument and multi-engine ratings. Ells also loves utility and bush-style airplanes and operations. He’s a former tech rep and editor for Cessna Pilots Association and served as associate editor for AOPA Pilot until 2008. Ells is the owner of Ells Aviation (EllsAviation.com) and the proud owner of a 1960 Piper Comanche. He lives in Paso Robles, Calif. with his wife Audrey. Send questions and comments to editor@www.piperflyer.com.
RESOURCES
Custom aviation fuel gauges
The Original Dipstik
dipstikfuelgauge.com
Universal fuel gauge (26 gal.)
Aircraft Spruce & Specialty
Aircraftspruce.com
Chieft Aircraft
chiefaircraft.com
Sporty’s
Aircraft batteries
Concorde Battery Corp.
concordebattery.com
Gill/Teledyne Battery Products
gillbatteries.com
Battery charger
BatteryMinder
batteryminders.com
