Two thoughts:
I prefer the maintenance free battery that does not have to have water
added and can't spill acid.
If you want to be visible, you should get the system that flashes the
landing lights (and decreases the load demands)
Dan C
On Jun 16, 2010, at 2:43 PM, William R. Bayne wrote:
>
>
> Battery water consumption varies with use and seasonal ambient temperature
> and humidity. I would speculate that the battery specification, plate
> construction and water consumption differences greater between manufacturers
> than between battery sizes. Mixing the two just muddles the data.
>
> Observation is but the beginning of evaluating available options so as to
> reach a timely and appropriate decision. It is just as effective to reduce
> electrical load as to increase capacity. There are many 13 amp generators
> "out there" still giving reliable service so long as limitations are known,
> weighed and and allowed for in both daytime and night operation. Modern
> avionics require less electrical power than older stuff. Old rotating
> beacons are real power hogs, as an example; and should be replaced by
> strobe(s).
>
> You are not depleting your battery's "reserve capacity" (from fully charged)
> even when generator output falls to 100% of connected load. Your wording
> suggests that your landing lights are only on when coming in for a night
> landing. The few minutes in the pattern when your actual electrical load
> might exceed 25 amps should not deplete a healthy battery such that the GPS
> ceases to operate. Once one is in the pattern and landing, you already know
> where you are. I would be much more concerned if I lost my radio voice
> communication.
>
> Landing lights are a luxury a pilot should be able to do without when the
> airport has runway lights and they are are on. The "joke" about a night
> off-airport landing is to turn on the landing lights just before touchdown.
> If you don't like what you see, turn them off ;<)
>
> On the other hand, If you like to go up shoot lots of night touch and goes,
> or if you deem your landing/taxi lights "necessary" for extended periods for
> additional insurance against a midair collision, the 35 amp
> generator/regulator could better fit your "mission profile" than a bigger
> battery for about the same weight penalty. It came with the 90 hp engine and
> the 25 amp battery in Forneys, Alons and M10s.
>
> Regards,
>
> William R. Bayne
> .____|-(o)-|____.
> (Copyright 2010)
>
> --
>
> On Jun 16, 2010, at 13:32, texasaviator wrote:
>
>>
>> My personal experience with batteries, for what it is worth;
>>
>> When I bought the coupe it had a 35 amp Concorde in it.
>> It lasted 9 years.
>> I now have a 25 amp GILL in it and have to keep adding water to three of the
>> cells about every three months.
>>
>> I have upgraded the generator from the piddling 13 amp generator to a 25 amp
>> generator and now have the required 15% ( or whatever) more amps generated
>> than consumed at peak consumption time, which is when I am coming in for a
>> night landing, have GPS, radio, landing lights, strobes, MRX and transponder
>> all working at the same time. the problem is that I have the engine
>> throttled back to 1000 rpm or maybe 1500 rpm so the generator is not really
>> putting out 120% of the consumed amps.
>> It sucks when your GPS goes off on the approach... So the 35 amp battery
>> seems to make more sense.
>>
>> In the other coupe I have a 60 amp alternator that should put out enough
>> amps at 1000 rpm to keep everything running bright even with a 25 amp
>> Concorde behind the seat.
>>
>> AF.
>> N87333
>> N94694
