Review (5/5): Fix the leak issue, and the toothbrush is superb
Since I originally wrote this review, I bought 5 of them, over time. All are still working.
I've used Sonicare since before they were bought out by Philips. One thing I hated in over 15 years of owning them is the battery dying out, it lasts about 5 years, and I've gone through 3 versions already. While a new brush will hold a charge for over a week, after 3 years, it will give about 3 days sometimes not, so if you travel with the brush you'll also have to lug the charger, otherwise you'll have a useless brush with no power sometime in your trip. The brushes still use NiCD, so you get a memory effect and to revive it you have to recharge best when the brush is dead; to do so you have to endure the increasingly weak brush stroking and it dying sometime while you brush. You can't just leave it on, all Sonicare's have a 2 minute timer, Quad Pacer or not.
This AA powered Sonicare I've had for 1.5 years, and it works as good as the rechargeable versions except it doesn't have Quad Pacer, not a problem. As a brush, it has the vigor and thus, the benefits of what made Sonicare famous.
I was concerned about Amazon reviews of water leaking into the battery compartment. I've tested the brush since then, and found what the weakness is; not cleaning the battery compartment O ring seal after each battery replacement.
Like many items used for water, you should clean the battery compartment O ring and its sealing surfaces thoroughly before resealing it. The head usually has toothpaste on it that is abrasive and gritty and will break the O ring seal if not washed clean out. All a user need do is during a battery change, use an old manual toothbrush to brush clean the open end cap until its clean of all debris. Wash the O ring with soap and water. Let both air dry to avoid getting lint on the cap or ring. Use a clean finger to wipe clean the interior battery compartment to insure its clean or clear of residual toothpaste, as this is the other half of the sealing surface that contacts the O ring.
When ready to seal, take a tiny dab of vasoline or silicone O ring lubricant between your thumb and forefinger, and pass the O ring through these fingers so it has a light coat of lubricant. This prevents the o ring from twisting as you insert the cap, and breaking the seal. Place the o ring on the cap, and push on the Sonicare. That's it!
I use NiMH batteries, and a new set lasts over 2 months, brushing once a day. I can even use my old used NiMH cells on this brush, and I get about 1 month.
The O ring should last over 5 years but if you know O rings, it AS568A size is -023, change them every 2-3 years. These rings typically cost 1c each, but the problem is finding them, usually they are sold in industrial supply houses.
The toothbrush has held up, so it won't die because of leaking or bad battery. For $25, this unit is an ideal Sonicare. Now if only the brush heads were cheaper.