Monthly Science: Sonicare Recharge Intervals

After replacing the NiMH cells in my Sonicare toothbrush in July 2012, they delivered about 21 days = 21 brushings between charges. After a year, I laid a sheet of Geek Scratch Paper on the windowsill (*) and noted pretty nearly every recharge:

Sonicare recharge - 2013-10 - 2017-01
Sonicare recharge – 2013-10 – 2017-01

Anyhow, the original cells crapped out after 2-½ years, when these still delivered 13 days. After 4-½ years, they’re lasting 12 days between charges.

Color me surprised, because they’re 600 mA·h NiMH cells. The originals were 2000 mA·h cells, which you’d expect would last longer, but noooo.

No reason to change them yet, which is good news.

FWIW, I recently bought some cheap brush heads from the usual low-end eBay seller. The OEM brushes have colored bristles which fade to tell you when to change brushes, although I run ’em quite a bit longer than that. The cheap replacements have never-fading colored bristles and, I suspect, all the bristles are much too stiff. The dental hygienist says I’m doing great, so it’s all good.

Sonicare brush heads - cheap vs OEM
Sonicare brush heads – cheap vs OEM

High truth: at best, you get what you pay for.

(*) Being that type of guy has some advantages, if you’re that guy. Otherwise, it’s a nasty character flaw.


9 thoughts on “Monthly Science: Sonicare Recharge Intervals

  1. I was thinking about this just the other day. I bought mine in 2004, used it for several years and then didn’t use it for several years…and now I’ve used it for several years, and it lasts about 2 weeks between charges. I got some brush heads from Wallymart which work fine.

  2. Our older power heads (circa 2009) went out with low batteries; I have two in the round-tuit stack for battery swap. We bought 4 new sets from Amazon; no 30 second chirp, and the charger is different (Phillips says the chargers are not interchangeable; the old chargers will cause the LED to light up on the new handles, but won’t get a decent charge). We leave them on charge when not using them; I rather like them as a night-light. [grin] On general principles, I swap power heads every month.

    I looked into the Latest And Greatest Sonicare brush system, but the reviews were not encouraging. Costco still sells packs of the Elite brush heads. I liked the original style of head from the pre-Phillips days, but they’re long gone.

    1. For SCIENCE!

      FWIW, the brush on the right came from my deader assortment on the I-beam over the workbench. Those magnets seem too good to throw out, but cracking them off the lever arm seems fraught with peril.

      I’d lay long odds my cheap new brushes have smoothly rounded bristles right from the start; obviously, I need a metal deposition setup next to a SEM.

      1. metal deposition setup

        Uncoated nonconductive surfaces can be imaged with a SEM, but it tends to fade as charge accumulates. The truly insane (or those willing to risk it) may note the availability of desktop SEM units.

      2. The magnets come off pretty easily most of the time, and are in fact darned handy to have around.

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