Philips Norelco HQ8 Dual Precision Heads

I have purchased 2 of these sets of HQ8's from Amazon (Nov. 2013, and July 2009) and one previous from a retailer locally. I use the for my Norelco Spectra 8894XL. I don't remember exactly when I bought it, but the oldest review of the razor is dated 2002, so mine is at least 12 years old (still running like a champ) and I am on my 4th set of cutter heads. Unlike many, I don't shave every day, but usually every other day, and I sometimes use a hand razor and lather. Consequently my blades last longer. These blades fit perfectly, are well made, and include new cutter screens along with the blades. Once a week I clean out the interior of the the driving head on the 8894XL with an old stiff bristled Windsor-Newton artist's brush (way better than the supplied razor brush) and tap the detached cutting head on the sink and blow it out. After that a take a touch of clipper oil on my finger tip and run it over the screens. Once a month I brush the razor interior and flush it with warm water and disassemble the entire cutting head, brush it out then rinse with water, dry add the oil and reassemble. Finally once every 4 months I do the same, but in addition I take the entire disassembled head assembly, place it in a jar with rubbing alcohol, then place the jar in my water filled ultrasonic cleaner which really gives things a good cleaning. My main point in going through all of this is to preserve my Spectra 8894XL as I have read reviews on the newer Phillips and Braun razors and they have nor been all that great! Many have died in a year or less. I'm surprised after all the time I've owned the razor it still keeps a good charge. As recently as last November, 2014, i went on a 7 day trip and left the charging cord at home. When the battery finally does die I will try to replace it my self. I have already removed the back to take a look and the battery is indeed hard soldered./ That being said there are also many videos on you tube showing you how to replace the battery on your own.