12 Volt 18 AH SLA Internal Thread Battery - Pack of 4

This battery worked reliably for seven years before it died at the end of its' expected life.

This is the second one of these that I have purchased for use in my experimental homebuilt airplane. The originally intended battery which retails for $100+ more than this one is the PC-680. This is a drop in replacement for the PC-680. Has never failed to briskly start my Lycoming 4 cylinder 180 HP engine. I have dual alternators installed so once the engine is running I don't really care what happens to the battery. If I only had one alternator and needed to rely on the battery for back up power if that single alternator ever failed, well then I might find value in spending 3x's the price for a battery with a better pedigree. At this price it makes sense to simply replace the battery every year or 2 before the performance starts to get soft, I always have an almost new battery installed.