RTC Issue

[coldweathersucks]

We have a Load-Rite Pro LR918 loader scale. The device does not keep time anymore.You can set the time but it doesn't advance at a proper rate and usually within 1 week it is about 6 days behind. I opened up the scale main control unit hoping to find a battery but there was none there. I looked into it further and found a M48T35Y-70PCI RTC module in there. We have had this scale for about 5-7 years now if not longer plus the loader at times sits for days on end without being used so I am assuming whatever battery is keeping the time is dead or almost dead as this is something that has only become an issue within the last couple weeks as it seemed to have been working good up till then. Is this device replaceable or is the battery inside it replacable? I have found a complete replacement device on the digikey website but after doing some reading it looks like it needs to be programmed before using if I am not mistaken and if that is the case I have no way to program it so I would prefer to do a internal battery replacement if possible. Also, is there any way to do some self diagnosing on this device to know for sure if it is a battery issue or not.

 

Your help would be greatly appreciated.

[Tesla DeLorean]

If the battery has failed, the device has already likely lost whatever content is on-board. Hopefully the module is socketed, and you can reinitialize it from scratch from the user interface on the scale. At the very least you can swap out the units and see. The DIP device doesn't have a replaceable battery, although I'd imagine there are videos or how-tos about deconstructing the case and wiring an alternative source.

https://www.st.com/resource/en/datasheet/m48t35.pdf

[Tesla DeLorean]

This guy used a SOIC conversion board so could use the ones with the SNAPHAT.

https://www.youtube.com/watch?v=Ec2nNtTJPiA

I believe others have used a dremel to expose the battery connections, and used a CR2032 battery/socket combo

[coldweathersucks]

Hmm...I have found a new module available online but i don't know if it needs programming or not.  Are you familiar with how that works or if it can just be a plug and play type situation where you just replace the old with a new?

[Tesla DeLorean]

It's a 32KB SRAM with an RTC. If the battery is failing now, and you can recover it, then the scale firmware can likely recover from the fact it is empty/blank.

You'd do better asking in a forum related to the scales, or the manufacturer.

You could make an adapter to read out the content, and push it into a second device. I just don't know if there's something prebaked to make that simple/easy.