My N35 used to overload and reset on charging, refer to this forum, and as expected it broke down completely one or two months after. I dismantled it, checked the battery, which was dead.
I ordered a new battery, not the N35 type because it showed 5 wires on internet, where mine has only 4. So I ordered N30 replacement, it fitted in, and worked. It did not load, though. I then cut the wires of the old battery, and compared all voltages to the new battery. There was a fuse on top of the battery that was open, but I think that happened after the last time the N35 worked.
The only remaining solution was to make a new cable with a PC-type connection, guide it through the back of the N35, and connect the original and fixed battery externally. It seems to work fine now, I can observe and measure charging current as well as operation voltages etc.
Anyone interested, give me a signal via this forumthread and I'll give you any details you like.