I have had my Fluke 233 just over 4 months now, over which time it has had pretty light use. Which is why what I am about to say is a bit of a surprise.
In my review I wrote:
Batteries. 400 hours estimated life is excellent. That probably works out at 3 to 4 years usage for me. But, when they go, it does mean potentially 5 batteries have to be replaced.
I have used it for maybe 5 hours use at the outside, and not at all for the past month or so (sadly, my engineering has mostly been on paper or PC recently). That doesn't sound much, but it adds up to quite a few voltage and resistance measurements.Anyway, I came to use my Fluke 233 today and this met me:
Pretty much running on empty! Removing the remote head results in a BATT warning and no measurements are possible. If I am going to be installing a new set of 5 batteries every 4 months then it becomes a very expensive meter! I had thought that using high energy density AA cells was a good idea (the cells it came with were brand new Duracells with a very long use-by date), but maybe Fluke are covering up some nasty quiescent current use. Swapping out the batteries allowed me to test the off-load voltages, which were all around 0.95-0.96 Volts, so that rules out a rogue cell failure. My investigations with my trusty Fluke 77 (battery age 4 years) revealed the following:
Body power consumption, power ON = 3 to 6mA
Body power consumption, power OFF = 0.9 to 1.1mA
Display unit, power ON = 3 to 3.6mA
Display unit, power OFF = 1mA
Looking at http://www1.duracell.com/oem/Pdf/new/MX1500_US_UL.pdf the nominal capacity for <5mW drain is 1600 to 2300mAh (to 1 volt). 2300mAh at 1mA, is 95.8 days...
You will note that an "on" life of 3mA is 766 hours, and 6mA is 383 hours, which averages close to the specified taget of "around 400 hours". Presuming you use your meter 24 hours a day, and don't actually switch it off...
Given the recently found RF vulnerability in the Fluke 87 V, it does make me wonder if Fluke are taking their eye off the ball. It surely cannot be right that a meter eats a set of 5 cells in 4 months, especially given such light usage. This is certainly not the sort of meter to leave in your tool case, because chances are that the batteries will be flat when you need it.
If any other Fluke 233 owners have experienced any similar failures, please let me know!
If any Fluke reps see this: Is there a known fault with the 233? Because this does look like a bit of a killer design issue.
Mike
