Must have STC.  Use the Gill.  You cannot use whatever you want in aircraft.

STC  Suplimental Type Certificate.  Gill is brand of aviation batteries that work well.

Will:

There are a few battery manufacturers out there that have FAA-PMA batteries for a Cessna 150.  Your replacement battery does not necessarily have to be STC'd.  If you buy a PMA'd battery check the manufacturers eligibility list to verify it can be installed on your model.

Sal

Never mind, I just found that it is 250 cca.  This battery held up at a 300 cca test, only dropping to 9.60 volts, then recovering to +12 volts, so I think it is good.

For the past 20+ years, i've purchased my batteries from
these guys...I just havent been able to beat their "to my doorstep" price.
Chief Aircraft...link to battery page below...
<http://www.chiefaircraft.com/cgi-bin/air/hazel.cgi/hzpi/u/HzSt0205Czi31CVMCD/hazel.cgi?action=serve&item=/Aircraft/ElectricalSystem/Batteries.html#ConcordeStandard>

Have to agree with RH.......I don't stock or sell Gill batteries. Concordes are the only ones I install. Much cleaner, more power for cranking, less heat during recharge and handles cold soaking better....which is REALLY important up in SE Canada where RH lives.
Gregg

Will,

If the battery will not hold it's voltage, then it has to draw more current to get the same power.  This increases the current through the starter and may impact the starter life. 

I fear I just run into this problem as of late due too much cold cranking of the engine recently when the plugs had condensation on them.  I should have used a preheater.  It was 28 degrees in DE and had a lot of rain during the previous few days.  My plane's stuck at MYR (Myrtle Beach, SC) right now waiting for Monday morning to roll around and probably will need a new starter.  I may end up replacing the battery in the my C-172.  Looks like the Concorde battery is a good choice. 

Barry

Concords are service free but a bad choice if you dont fly much.  If you don't fly at least weekly get the Gill.  If you do fly frequently get the Concord.  Note:  Concord would not fit correctly in the battery box of my 182 - had to use a Gill which are very good batteries.

Regarding the shipping of batteries.  I've had both Concorde and Gill shipped to be from Chief Aircraft (Oregon State)  Both batteries came in a box that contained the battery acid in a seperate container.  I havent been charged extra for hazardous materials by chief.  They were shipped UPS ground.  I think Chief's website states whether or not an extra charge applies to particular batteries.  I'm sure there IS an extra charge if it's shipped by air...for the faster service AND hazardous material.  Shipping charges used to be included on the batteries...It's been about 4years now...I'll probably be finding out
if things have changed much in the not too distant future...
It definately does pay to shop around, if you can.
Blue skies...
Michael