I am a big noob in electronics but I like to thinker a lot and watching EEVblog.
So I have a keyboard
Logitech diNovo Edge for 8 years and my original battery died it can hold charge for 2-3 hours. I bought a new replacement battery. I installed the new battery but it`s not charging. When I put my keyboard on the charging station its blink once green and after that it blinks red. I switch it with the old battery and it works so I was sure the problem was in the battery. I emailed ElectroPapa.com and received a second battery for free but it has the same problem...
My theory : The battery for the keyboard have 3 pins (+,- and T) and the "T" on my new batteries is not working properly so the keyboard protection decides not to charge them so I want to bypass the protection. Pictures bellow show my idea will it work, will it explode , what do you think I have to do?
Greetings from Bulgaria and cheers to the professionals!
DON'T DO IT!
There is most likely a charging circuit between the charger connector and the battery connector, bypassing that will almost certainly kill the battery in no time
I think the charging circuit is in the charger ?
dont know about this keyboard, but logi mouses have charging circuit inside them, charging base is just a holder with connector
quick test if its the thermistor - wire up old battery ground and T + new battery ground and vcc at the same time
This could be the charger circuit:
Rasz i dont fully understand you...
you want me to connect the new battery + , - and only connect the old battery T and see if its charging ?
I made some photos hope they are helpful close up of the suspected charger board on the keyboard and two photos of the insides of the docking station charger.
The fact that you have a T connection going to the board points to at least some part of a charge circuit there, it is supposed to stop charging when the temperature rises too high. when you measure the voltage on the T for both for the old battery and the new one (while under charge) it could provide a clue why the new battery isn't charging.
Rasz i dont fully understand you...
you want me to connect the new battery + , - and only connect the old battery T
and ground
looks like your holder has smoothing cap and diode bridge
I wrote an email that the second battery was defective and got a refund ... so now i am wondering to buy a new battery from a different manufacturer or buy a cell phone battery same Voltage but 2x the capacity and half the price? Will it start working and if not maybe I can modified it to use the +,- of the cell phone battery and the T of the original? Will it charge correctly or explode
thanks for the help so far
why are you asking us? you have all the parts to test it
+ I didnt suggest connectoing thermistor of original battery as a permanent solution, just to check if your 'new' chinese batteries are ok
I connected the T of the old battery and tested with the two chines batteries its works ... got refunded and order from a different manufacturer now I will wait for two weeks and post an update