CORRECTION, April 7:
The mA reading from the analogue meter is wrong. The actual reading with a better meter is between 470 and 500 mA. I posted more information in another post below.
I just finished building a 48 Volt 2.4 AH battery back for my new DS1054Z.
The pack consists of 12 18650 Lithium batteries in series. I built a holder using 18650 battery holders from eBay.
The battery holders were hot glued to a 5mm piece of plywood and mounting tabs were also glued to the base. The battery holders provide slots for ribbon to help remove the batteries. The batteries are near impossible to remove without the ribbon and are susceptible to damage using tools like a screwdriver.
There is no way to charge the whole pack at once. It will take three salvos in my four slot battery charger to do the job. Not a problem for me because I do not expect daily use on battery power. I will use it for trouble shooting CNC equipment and would like to have the scope isolated from Mains Power.
The batteries are 2400mAh as measured on my battery charger. They are labeled as 4200 mAh
but they are about $20USD for 12. They are also labeled as "Protected" for what that may be worth. I would like to fuse protect the pack just in case.
I am using modified (screwdriver and hammer) female spade lug connectors to attach to the mains input. They are not bump proof so will look for a cord to scavenge for a proper connector.
Here are the power stats: Current draw from the battery pack is 225 mA at 48 volts. Thats only 11 Watts.
During boot up it drew only 190 mA. I will probably never run this more than 2 hours at a time with the batteries.
So the concept works. This blog was the final factor that sold me on this scope as I was also considering a hand held for Mains isolation but those would not be optimal for other projects and courses I am working on. 48 Volts straight into the AC power input simple beautiful.
Photos are attached.
The original intent for mounting was to use heavy wire hooked around the handle hinge pins but found that it requires some drilling which I am not ready for at this point so am just using string for the time being. Please, no one suggest peel and stick Velcro because the Velcro is generally stronger than the glue which fails and makes a mess.
If anyone sees anything dangerous going on here please let me know. I have a great deal of respect for the energy density of these batteries.