I am back with few more questions on my mind. My battery was dead, and my mojo was one of those not able to work connected to charger while battery disconnected.
So I unplugged the battery and dissected it. 2 li-ion cell and one battery circuitry came out of it. I kept the 2s circuitry and got rid of the rest. The circuitry looks like simple 2s charger circuit that has 5 pins;
B+, B-, BM, V+,V-
I had few 18650 batterie lying around, and a 2s battery slot with spring holder. So I gave it a try, charged my batteries, soldered the 2 pin plug, then connected to mojo mainboard without the 2s circuitry. Voila. Works like a charm. Downsides are:
1) Batteries need to stay outside of the mojo, so overall system looks like a Frankenstein.
2) I need to unplug batteries, and use a separate charger to charge it.
Good thing is I have 4 batteries, so while I use two, other two charges. And it takes about 8 hours to discharge one set.
But I want to turn it into desktop dac, and I want uninterrupted power supply. So I may do a supercapacitor mod but before that I want to use internal charging circuitry work again.
Remember I said I kept 2s circuitry. Today I soldered my battery contacts to 2s circuitry B+,B-,Bm pins. So battery pins read about 8 volts on voltmeter. However V+ and V- pins didn't give any voltage out. Maybe I burnt some chips during soldering, or is there any trick or reconditioning to work 2s charging circuitry again. I plugged battery+2s circuitry and plugged charger to mojo to give it a chance. Mojo did start boot sequence and after the boot it turned itself off. I left it about an hour to charge but it didn't change anything.
I have a Hx-2s-a2 li-ion charging board (a small circular shaped board) at my hand. Operating voltage of it seems like around 9 volts. So if I remove mojo 2s circuitry, and solder this hx-2s in, would that work. Does mojo internal charging circuitry gives 9v out?
Aside from this, do you have any diy project suggestion to make a 8 volt dc supply for mojo?