I think it is worthwhile to consider that batteries are DC storage systems. Their purpose (in aircraft) is not to start the engine. Their purpose is to provide an emergency-source of power when all on-board electrical-supply/generated systems fail. When your generator/alternator fails in-flight that battery exists in order to provide any necessary/required electrical-needs to get back onto the ground. The size/capacity/health of that battery will determine how much time one has to accomplish that task. And one of the MOST IMPORTANT pre-takeoff checks one should ADD to their pre-takeoff checklist is that the battery is NOW FULLY RE-CHARGED before taking off (especially into the dark or the clouds.). LOOK at your ammeter after engine-start! It should show a high-rate-of-charge, indicating your charging-system is properly-operational. LOOK at that ammeter before take-off... it should show a LOW or zero rate-of-charge indicating it has been recharged before flight. (Do this check with landing/taxi lights OFF.)
THINK about what you are doing when you find your battery low and incapable of starting...and when you hand-prop or jump-start your engine. Is that low-battery an indication you should not be launching into night or poor weather with a lousy battery or poor charging system?
In order for batteries to meet certification standards to be installed into aircraft they must accept the charging systems in those aircraft.
The OEM Cessna 170 charging system is a direct-copy of my grandfathers Chevy pickup, a Delco-Remy generator with a Delco-Remy vibrating-points regulator. This system does a fine job when working properly and aircraft batteries of any make/model must work properly with and not be damaged by that system in order to be approved for installation in the airplane.
The average/most-common usage of the batteries involves a period of storage, a heavy-discharge while an engine start is accomplished, and a re-charge of that battery by that Delco-Remy system, an hour or two of flight involving a “topping-charge” period of flight, followed by a shut-down of the system and another period of storage. The battery is purposefully designed for this service. It will serve several years reliably doing just fine with that OEM-design charging system.
No battery will last long if abused. Abuse would be letting that battery sit for months at a time with no activity... or being continuously connected to a maintenance-charger (MC) not designed for the battery. In my opinion, it would be better to NOT use a common lead-acid/automotive battery-charger as a maintenance-charger (MC). I’m certain that will dry-out/over-charge/damage and eventually destroy the battery. ANY battery. Including your grandfathers old Chevy’s lead-acid. Your aircraft battery is no different. And it makes no difference if it’s a Gill “pink-power” or a Concorde AGM, the result will be the same.
Both types battery will last longer, if connected to a maintenance-charger, if that MC has a long, slow, low-current provision that does not continuously and ignorantly keep trying to pump energy into that battery.
I don’t believe one has to pay high-prices for a simple task of sampling the current charge (pardon the pun) of a battery of WHATEVER type... and then gently bring that battery back to full charge... then shut down and monitor it again. I own a full dozen battery chargers. Three of them are common automotive types in the 10-20 Amp capacity-range. One is a a cheap Horrible-Fright “trickle=charger” that should NEVER be used as a MC. (I mostly use it for a small 12-14 volt power-supply for testing lamps, etc., but occasionally use it to re-charge other small batteries such as animal-feeders, etc.)
The chargers I use for maintenance-chargers are cheap, $10 Schumaker’s bought from WalMart. They are continuously kept connected to my Concorde AGM-equipped 170, 172, two boats, tractor, riding-mower, 2nd automobile and two spare lead-acid automotive batteries sitting over in the corner of the hangarI have no idea why I purchased. They keep all types of batteries in good health over the years without over-charging them and without “sulfation” issues. For $10. Model SC1299. I have six of them. They have kept my batteries in good condition for years, including my Concorde AGMs.
- E46DCCAB-CF81-4F5D-85FE-EB701D062CE8.jpeg (9.79 KiB) Viewed 12945 times
This charger is still sold for around $10 (despite the advertised online price) at WalMart. It has an LED indicator that “twinkles” when connected to power but not the battery, is on solid-green while charging the battery, is red when the leads are incorrectly connected to the battery, and is OFF when the battery is topped-off with a full-charge and is simply “monitoring” the battery during long-term disuse. I occasionally observe short, green, ON indications but most of the time the LED is OFF because the MC is only monitoring. They are a simple, effective method of keeping batteries on a maintenance-charge. Hope this helps.
Product Specifications
Battery Type: Standard AGM
Input Voltage: 120V AC
Input Current: 0.3A
Output Voltage: 12V
Output Current: 0.8A
Dimensions: 2.88 × 3.13 × 8.63 in
Weight: 0.7 lb
Safety Certifications: UL ULC
Warranty Period: 1 year
FOR MAINTAINING ALL POWER SPORT, CAR AND BOAT BATTERIES
Microprocessor controlled ─ automatically adjusts the amperage rate to charge and maintain
Multi-stage charging for added precision, safety and battery life
Float mode monitoring ─ automatically maintains optimum battery charge
Reverse hook-up protection ─ charger will not operate if clamps are reversed
Charging status LED indicator
Schu Eco Energy ─ meets the highest industry standards
DOE compliant
Contents: (1) SC1299 battery maintainer (1) battery clamp quick-connect (1) manual