Hi,
I was actually looking into the Lithium option, I have found a really
neat solution online:
But for the time being I went with the old technology, for the simple
reason that I had a bunch of NiMH AA cells with solder tabs. So I hot
glued 14 of them together 2x7.
2 connected in parallel and then 7 of these pairs in series. Then it
got wrapped in kapton tape. It is even about the right size
mechanically. I'm not sure if the scope will be able to charge them
fully, but the voltages are about right. But I can always charge it
externally if needed.
So far it works nice, will do some testing.
Szabolcs
<tekscopegroup@...> ezt ¨ªrta (id?pont: 2018. szept. 26., Sze, 17:49):
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Hi, what type of battery and voltage are you going to use? Some time ago I did go as far as Installing a 2x 18650 batteries and holder inside the battery bay of my 222 and it works quite well, but I still have to charge the cells on an external charger base. I also connected a very low dropout "super diode" in series with the battery pack to prevent any direct uncontrolled charging when the scope is powered with the external DC adapter. The idea would be to one of these days add one of those inexpensive charger modules sold on ebay so the batteries can be automatically be charged inside the scope. Also another issue is the cutoff low battery voltage originally used by the scope that is set for the 8V lead-Acid battery pack at I think it was 7.5V IIRC, so it is much higher than the ~6.4V (3.2v x2) minimum permissible voltage for the two Lithium cells in series, so the scope turns off prematurely while there is still plenty of juice left in the Lithium cells. My cells actually have an internal Hi/Lo voltage cutoff and protection build-in, so the cells are actually a bit longer than a regular 18650. In any case there is a resistor value in the battery sensing circuit divider chain on the A2 board that needs to be changed to adjust the cutoff point, which is also something I still need to do as well. I have some notes on this info would be useful. One more project on my list waiting for me to get to get back to it.
In any case it would be nice if you can post any updates to your project. It might even make me dust off my own and finish.
Alex
