Fluke 233 Meter Review - Important Follow-up

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

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DutchR_PW

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1. Dec 20, 2010 10:23 AM (in response to Zad)
Re: Fluke 233 Meter Review - Important Follow-up

Hello Mike,

Coincidentally, the batteries of my Fluke 233 died last week, after approximately 4 months of light use. As I suspected in my review and which you confirmed above, it is not possible to turn off the Fluke 233 completely, causing it to eat batteries, even when it is not in use.

In their next wireless multimeter, it might be wise for Fluke to include a On/Off switch on the wireless module, to allow users to switch the meter off completely when it is not in use. For the Fluke 233, I can only recommend removing the batteries when the meter is not in use, although this is obviously not a very elegant solution.

Patrick

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gbrettell

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2. Mar 17, 2011 7:25 PM (in response to Zad)
Re: Fluke 233 Meter Review - Important Follow-up

I have experienced the same problems with my unit (as Mike & Patrick have noted above) ... I have used my unit very 'lightly' ... total "ON" time is probably < 20-hours. I always turn if off when I am not using it to conserve on batteries ... well, so I THOUGHT.

The batteries are being slowly depleated even without use ... seems like a design flaw (or oversight). I wonder if there is a way to fix this with a firmware update that would power down the unit completely?

Gregory

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Zad

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3. Mar 21, 2011 6:01 PM (in response to gbrettell)
Re: Fluke 233 Meter Review - Important Follow-up

I'm glad I checked this forum today, I think the auto-email thing ceased to function a few months ago. I think it is about time for me to follow this up directly with Fluke. This is now at least 4 people who I know of that have experienced unacceptably short battery life. I'm not sure they can be flash upgraded, as neither section has anything resembling a JTAG connector. There are some test points, but they look more analogue in nature. Let us see what Fluke have to say.

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JimNewell50

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4. Mar 22, 2011 10:07 AM (in response to Zad)
Re: Fluke 233 Meter Review - Important Follow-up

Hello Viewers, The 233 is unique in its design and implementation with its wireless display utilizing both iR and RF communication between the meter base and the remote display. While docked the meter utilizes iR communication and when the display and base are separated RF communication is used. When new the meter is shipped with paper tabs inserted into the battery compartment for both the base and the display to keep the batteries disconnected from the meters power supplies. This is to insure that the batteries have a full charge and the customer gets the longest battery life possible. The reason for a short battery shelf life is that when the meter is turned off and the display is mated, the iR communication is still active. This was done by design to give the user the most flexibility when using their 233 meter. The design allows the user to power on and to wake up the meter while the display and body are disconnected. It simplifies the meters operation. This use model was important to customers during our initial research for the 233. The alternative would have been to have two separate power buttons, one for the base and one for the display. Our research indicated that this was a less attractive solution to our implementation of one power up option for both parts. The trade off is the unit consumes more power but gives the users more flexibility. If the meter were to go into battery save mode and the iR communication were not active, the display and meter body would need to be re-connected before the display could power up. This option and two separate power up processes were not attractive in our research. To optimize the battery life, for intermittent use or extended periods of storage, it is recommended that the paper tabs be re-inserted into the battery compartments or the batteries be removed completely. Jim Newell Sales & Application Engineer Fluke Corporation

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K5HJ

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5. Mar 25, 2011 3:16 PM (in response to JimNewell50)
Re: Fluke 233 Meter Review - Important Follow-up

I never pay more than 50 cents each for premium alkaline cells, Duracell, Energizer, etc.. Usually less. I would not consider 7 - 8 dollars per year to be "Very Expensive"

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Zad

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6. Mar 27, 2011 1:30 PM (in response to K5HJ)
Re: Fluke 233 Meter Review - Important Follow-up

K5HJ, unfortunately we don't all live in countries where premium alkalines are 50c each. £150 over 10 years is utterly ridiculous.

On a more positive note, Jim, might I suggest some inexpensive yet effective design amendments for the next revision of the 233? Principally that the IR transmit LEDs are driven through higher value current limiting resistors. The range only need be short and they are currenly bright enough to be seen by my camera across the other side of the room. Additionally, rather than running the IR transmit ALL the time, reduce it to a couple of bursts a second. By my calculations, this would increase battery life to a more reasonable 2.5 years. Latency between operating the power switch and activating the display should not be compromised in any way, as the IR will start to transmit on power-up and the head unit should be interrupt driven anyway. It just means that there will be a maximum delay of 0.5 seconds when undocking/docking when switched off, which the user will not notice anyway as the unit is off.

When it comes to a re-design, docking and undocking detection must be a priority. There are many passive methods that can be used to detect a status change, whether it be a pair of switches, a magnet+sensor, or a shorting contact built into the docking rails. These would all allow the controllers to fall back to a micropower state rather than being active all the time, driving a current hungry output. As they replace the IR functionality, none of these methods would compromise functionality demanded by your marketing executives.

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Morten Beyer

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7. Mar 31, 2011 4:24 PM (in response to Zad)
Re: Fluke 233 Meter Review - Important Follow-up

It seems to be a problem with other Fluke instruments as well.
My Fluke 123 scopemeter is suffering even worse from this.
I use it maybe 15 minutes once a month, and every second time I need it, it's out of power, partly due to 1mA standby current, partly due to poor rechargeable batteries, that sure were cheap for Fluke to include, but not really suitable for the purpose.
At least Fluke could write this in their datasheet, instead of letting people find out after paying for something that does not work as expected.

......add to that, a software error that does not allow for a battery refresh, and you see where this is heading.

This by the way seems to go for the TiS cameras as well.

I will go as far as saying that this was the last Fluke product I intend to buy, as Agilent offers at least the same or better quality these days, and cheaper.

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JimNewell50

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8. Apr 1, 2011 9:09 AM (in response to Zad)
Re: Fluke 233 Meter Review - Important Follow-up

Hello Zad,
Thank you for taking the time for your important feedback. I will pass your comments on to the product design team for future consideration.

Jim Newell

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SGT_BEAR

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9. Dec 25, 2011 3:13 AM (in response to Zad)
Re: Fluke 233 Meter Review - Important Follow-up

I have the Fluke 233 since 1.5 years, and i had to replace my batteries very often, and in Switzerland are Batteries very expensive (5 LR6 Cells for the device are around 12$). So i tried to use rechargeable batteries, and it works fine. So you can buy 10 rechargeable batteries and you run better and cheaper then buy normal cells.

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