Old fluke scopemeter with LI-ION battery

[dtmf]

What You Need:
1.Power bank box for 1$
2.Inductor
3.1000uF+100nF capacitors.
4.18650 or other li-ion battery
5.cell phone charger

[lamello]

Hello,

I like the idea, but I don't understand what to do.

Could you give some extra info?

Tia spock

[SeanB]

Take the 18650 cell out of the power bank and fit in the battery compartment. Then take the power bank end and remove the USB A socket that you would normally plug your USB device into. Then use the inductor and capacitors to make a LC power line filter on the charge PCB. Cut the end of the power bank off and fit into the scopemeter in place of part of the battery compartment door, so you can plug in a regular micro USB phone charger ( any semi decent one, just has to provide 5V at 500mA) to charge the cell. The original 4V8 4 cell power pack connectors are now connected across the capacitor you added, so the scopemeter now runs off this filtered 5V supply from the power bank.

Charge the unit with the cell charger and when full you unplug and use as normal. Runtime will be somewhat longer, but there will be no real low battery indication, it will just turn off after the cell protection disconnects the load.

[dtmf]

SeanB is 100% right.
I use 2x 2500 mAh in paralel (removed from android tablets).

[lamello]

Thanks for the info.

Just one question. With this modification, can i still use the 15Volt adapter?

TIA lamello

[SeanB]

No, you have to use a cellphone charger, the charge circuit will not work with voltage applied to what is nominally the 5V output.

[lamello]

Thanks SeanB,

I understand that the recharger in the pm97 will not charge the li-ion battery.
But my question was about safety. Can there be a hazard, like a fire li-ion battery, if the 15 volt adapter is connected?

TIA lamello

[dtmf]

China power bank with universal IC FM6316 is bad idea.  Burned after few hours.

Next attempt Two independent modules: charger and DC/DC step UP with MT3608 (2A output)

[Samogon]

Why just dont use new battery?