RTC Battery and Hydra

To enable the Real Time Clock to maintain time in a powered off state, I have connected a LR44 battery, + to pin 5 socket 1 and - to pin 10 socket 1 on my Hydra main board as per the schematic. However when I apply power to the Hydra the TE35 LCD screen back light illuminates but nothing else occurs. When I remove the connections for the battery everything works fine, but of course the RTC does not maintain time.

Am I doing something wrong?

I think the voltage is 1.1v max on hydra rtc. Please check the datasheet.

@ andre.m - it should be max 1.2 not min.

@ Gus - The LR44 was a 1.5 volt battery, I just tried a rechargable rated at 1.2 volts, tested at 1,25 volts, and had the same issue and then tried a rechargable that had been drained to .79 volts and still had the same problem. Are the pins that I am using correct?

Hopefully I didn’t damage something. I had read on the schematic that it was 1.2V but I couldn’t obtain any non rechargables at that voltage and the rechargables don’t keep the charge for as long as required for the application.

1.2v is very odd but unfortunately this is what the processor needs. It is possible that 3v did damage something.

According to the datasheet (see attached image), unless it was prolonged exposure to the 1.5V (Absolute Max VDDBU), no damage was probably done. Otherwise, the device may become unreliable.

@ Aron - Other than what I indicated when I tried batteries, the Hydra is working normally . The Real Time Clock has been running under normal power input from DP module and is keeping accurate time. I have loaded various test programs and they have all loaded and functioned properly. Thus the main core seems fine. I am borrowing a power supply from our tech department and will try various voltages starting at 1 Volt then going up to 1.2 Volts and see what results I get. That will not solve my battery requirements. I will also test my raptor board. May have to switch boards, which is a bummer as I purchased 3 Hydras for this project, if I can’t get it to work. I assume someone has done battery power for the RTC on the Hydra so I am puzzled about my issues.

@ Aron - I must of damaged the Hydra. Using the adjustable power supply, I was able to get my other Hydra to work properly. Now I must figure out what to use as a battery.