For some reason this was exacty was I was looking for. Many thanks for an informative video! It is quite easy to change the voltage from the charger to about 8.4V. Simply change the resistor R2556 from 5.62k to approx 5.8k.

Very nicely described and implemented. I like the way you share your thoughts as you are considering your options and then explain why you made a particular decision. Nice video.

Thanks for doing this video. I have a scopemeter like this with, of course, a completely dead NiCd battery. This gives me some ideas on how to upgrade and regain battery powered operation.

Very nice job as usual. Thanks for sharing!

bloody clever idea, if I may say so :) thanks for sharing this

Thanks! I too have an old Fluke 97 that works great except for the battery pack and I never thought of just sticking lithium batteries into it, but your video made it obvious. I'm not into tearing apart old laptop packs so I got a pre-made, dual-battery 18650 pack with charge limiting and protection from eBay for $11 and tiny 3-pin connectors, drilled a hole, did a little soldering, and there you go. Brilliant!

@feedback-loop

6 жыл бұрын

Very cool. I still didn't have a chance to look at 8.4V and faster charging mods.

@sleibson

6 жыл бұрын

If you do find a way to up the charging current, I'll be waiting. Wanted you to know that Excess Solutions has some large 0.6" LED 7-segment displays that would be perfect for your Datron voltmeter. They're not overmolded so you can sneak a small red LED between the exposed segment light bars and into the center of the digit for those special red dots the meter needs: Litronics DL747. $1.50 each. I went there personally to check them out for you. I think you'd like them. Stock # ES6459.

@feedback-loop

6 жыл бұрын

Well, what about the special symbols? I still like the idea of several graphic displays. I even bought OLED modules, but too little time...

@sleibson

6 жыл бұрын

Sorry, must have forgotten any special symbols beyond that extra dot. I watched those videos a few months ago.

Good idea! I've done it on my PM93 and works fine.

I have the exact same Scopemeter that I'm trying to retrofit with the exact same 10-year-old Sony Lithium cells... I almost can't believe this video exists. Thank you!!

@feedback-loop

4 жыл бұрын

You are welcome. Check out the follow-up about the 8.4V charging modification: kzread.info/dash/bejne/fpiHm6aopJW_p84.html

@Russell218

4 жыл бұрын

Have you considered replacing the Electro-luminescent LCD backlight: www.digikey.com/product-detail/en/COM-10799/1568-1340-ND/5768318/?itemSeq=300891090 I would be interested in seeing how that modification goes. It would be nice to have an actual white backlight instead of that ugly 1990's blue "indiglow" backlight. The thing I worry about is that some people report that the Sparkfun panel is blue, whereas others say it's white. The actual color depends on the frequency driving it. I've always wondered if that frequency can be changed by simply swapping some passives. Some people have also reported a large boost in the backlight brightness by simply re-capping the drive circuit. Have you looked into this at all?

@feedback-loop

4 жыл бұрын

no, I have not.

@user-qz4yv6ix2i

3 жыл бұрын

@@Russell218 давно заменил подсветку, купил с выгоревшим люминофором. С планшета Андроид 4.3 , разбитый экран, вырезал по размеру подсветку и белые светодиоды, ламинировал в пакет. стало замечательно!

Yes, it was the Philips alliance which resulted in the Scopemeter concept. Some of the best built laptop supplies I have seen are the old Dell PA-6 power supplies which were used from everything from the lower-end Latitude laptops all the way to Precision Workstation models.They have 130-degree rated Rubycon capacitors in them.

I bought a Philips PM97 for $150 today. Looks identical to the Fluke 97. I might try your lithium battery conversion om this one. 👌🏼

Thanks for your nice videos

Nice work!!!!

Great solution :)

Same problem here with a scopemeter. Have to look, which it is and how i get cracked the batterieproblem. Thankyou for sharing this video.

I bought the aftermarket nicad-battery for my 98 and it stays on between 8 to 9 hours. I've tried it twice now. I'm very impressed.

@feedback-loop

Жыл бұрын

Very good, but remember, NiCad is an old technology. It has high self-discharge, it has memory effect, it degrades way faster than Li-ion, it can leak.

Nice project, I would definitely be looking into the 8v rail to try and boost it up, what about a boost/buck converter running directly from the power input jack? That would allow higher currrent and higher voltage charging.

@feedback-loop

6 жыл бұрын

It needs to be seen how such an addition would interact with the existing circuitry. It might be easier to slightly shift some thresholds in the existing converter.

Interesting video as always. I have an older Scopemeter as well, 100MHz I think, and it will not run on batteries even though they are fully charged. Got to pull it off the shelf and have another look at it one of these days.

@gordonwedman3179

5 жыл бұрын

Well I fixed this problem. Turned out one of the wires going to the battery terminals was corroded and not making a proper connection. Now I just need to replace the flaky keypad.

Have I missed something? which unit is properly charging the cells? I have never found a battery management board that will accept say, any voltage, regulate to charge a Li-ion, AND allow an output from the Li-ion with just two wires or did I miss something in your video? Thanks.

Very nice and informative video! Did you have a look at raising the charging current and charging voltage to 8.4 volts?

@feedback-loop

Жыл бұрын

Yes. kzread.info/dash/bejne/fpiHm6aopJW_p84.html

Hi. Please tell me. Is it possible to supply 8.4 Volts to the input of the battery compartment. I want to use two 18650 batteries in series. I will charge them separately from the device. 8.4 Volts not dangerous for the device?

I like the ideal of rewiring the tray to 2s2p for 26500 batterys since they are c size, saft makes ones that are 7700mAh but is 150mA continuous. Did you take note of amp draw of this fluke 97, I would be moding a 105b? Another battery I see that can fit the tray with slight room for a bms would be using 2 26800s, this would be a means without modifying the unit. Good ideal none the less and thanks for the info on this thing charges the battery.

Awesome re-use of batteries! Did you time how long the Li-po pack kept the meter running? 11hrs or so perhaps?

@feedback-loop

6 жыл бұрын

No. I spent so much time on experiments already, so I didn't feel like running another long one.

@MrDubje

6 жыл бұрын

Fair enough! That takes time, indeed.

@feedback-loop

6 жыл бұрын

I finally tested this. The meter run for 10.7 hours. I posted the graph in the forum.

@MrDubje

6 жыл бұрын

That is very decent! Both your and mine estimation seemed correct. :)

Just acquired one for $10, like your no accessories, not even the yellow 'rubber' cover. Very will done video !!!!

@feedback-loop

6 жыл бұрын

$10? That is quite cheap. Is it alive? If so, you got yourself a great instrument for a great price.

Nice upgrade. Do you have the part number of the thermal fuse you used?

@feedback-loop

3 жыл бұрын

I don't. I bought something like this on eBay quite a while ago: www.ebay.com/itm/5Pcs-NEC-Microtemp-Thermal-Fuse-Axial-115-Celsius-Degree-Cutoff-2A-250V-SM110A0/182924401779

I'd love to get ahold of some of those Sanyo LiPo cells. I disassembled several MBP batteries and the cells I found in them are too wide. Do you have some extras you'd like to part with?

@feedback-loop

2 жыл бұрын

This video is about 5 years old now. A couple of modern 18650s with capacity of about 3000mAh and with 8.4V charging mod should give you close to 10 hours run time.

I have a fluke model 43 it's about 20 years old work but battery is garbage. I wonder if I should do the same to get long rilun times

Did you ever try to implement this mod to 867B?

Why would anyone give a thumbs down?

Rechargeable c batteries are probably the best option

@feedback-loop

2 жыл бұрын

NiMH? Why this would be better than the proposed Li-ion option?

How about usind recharcibel Baby C Cells i foundation eine with araound 5000mAh

Good videos. Any chance you can do something about the lighting on the next videos because I notice most are murky grey and hard to see. If you look at 15:00 on this vid you will notice it's bright and much easier to see.

@feedback-loop

6 жыл бұрын

I agree, lighting needs to be improved. Thanks.

I picked up a Factory refurbished Fluke 125 Scopemeter in a factory box. Uses NiMh pack. Would be interesting if I could convert it to 18650's. But the pack is 4.8 volts. 18650's are 3.7 to 4.2 maximum.

@jean-paulgagne5313

Жыл бұрын

I modified my Fluke 123 Scopemeter to use two 18650 in series by replacing R513 26.1K with 29.1K resistor increasing charge voltage from 7.4 to 8.4V.

The charger ALWAYS has to be higher voltage than the battery pack or the battery will not fully charge.

@feedback-loop

5 жыл бұрын

It is not clear if you agree or disagree with a particular part of the video.

Просачивается русский акцент :))

Was considering buying something like this www.amazon.com/Zeee-4600mAh-Hardcase-Connector-Vehicles/dp/B07F8T1NYQ/ref=sr_1_100_sspa?keywords=lipo+battery&qid=1552056934&s=gateway&sr=8-100-spons&psc=1 as more of a "drop in" Would probably come up with some sort of custom contact solution rather than drill any holes. Just enough room left over for a BMS too. Was measuring the current my 97 uses and it varies from about 270 to 760 mA, depending on voltage and whether the back light is on. Is that normal?

@feedback-loop

5 жыл бұрын

$33 with no BMS - not my idea of a cheap replacement. Is the run time very important for you? You may want to increase the charging voltage to 8.4V. Have you seen the follow up? kzread.info/dash/bejne/fpiHm6aopJW_p84.html I am not sure about 760mA. Seems excessive for an unmodified unit.

@nodriveknowitall702

5 жыл бұрын

@@feedback-loop No, I hadn't seen the follow up. I watched it just now. I really appreciate the time you put into this. I'll probably be doing what you've shown in your follow up. What I linked might not be a cheap replacement but I searched for 45 mins and didn't find much else that would fully utilize the battery compartment space and have much in the way of capacity. Everything else I looked at was either too long, too wide, or had a poor capacity. I don't have any lithium batteries sitting around to use aside from some old 18650s and only two of those will fit and that wouldn't give me the run time I want. I'll wait till I return to work and see if our IT department has some old laptop batteries sitting around.

@feedback-loop

5 жыл бұрын

A couple of modern 18650s with capacity of about 3000mAh and with 8.4V charging mod should give you close to 10 hours run time. Too bad there is no battery gauge.

@nodriveknowitall702

5 жыл бұрын

@@feedback-loop I just did some testing of the current vs. voltage of the 97. It acts like a constant wattage load from 9.77 volts all the way down to 6.20 volts, using about 2.27 Watts (no backlight and in scope mode, which actually uses slightly less energy). Wattage steadily climbs from there to about 2.88 Watts as the voltage approaches the shutdown threshold at 4.16 Volts. So your upgrade runs the instrument more efficiently than the NiCds or NiMhs. Your follow up, with the increased charging voltage should help quite a bit more. As an aside I pushed the voltage, on the battery input, all the way up to 12v and the instrument survived. I was living dangerously. I happened to notice that the meter side of it was giving an ac voltage reading with nothing attached. This artifact begins abruptly at 10.6 and disappears below it. Once I noticed that, I elected not to do any testing above 10 V.

@feedback-loop

5 жыл бұрын

Good to know. Thanks for sharing.

Русский?

Автор походу русский. Сними на русском пожалуйста. В совке такие приборы не юзают.