motherboard battery???

Hi again

I have an asus crosshair iv formula mobo and if I switch pc on, do what Im gonna do and switch off...then come back to it that night, its fine. :)

However, if I leave it overnight and all next day, I come back to it and it comes up with the bad checksum error.

Reading up on this, I have worked my way through any possabilities it could be (bad windows shutdown, battery, etc) and nothing has worked.

The only thing I can think of:- is there a "recharging" circuit on the mobo to recharge the battery that could be not working properly and therefore the battery is just going flat?

I have changed the battery for a new one, but same goes

Most motherboard batteries(at least all I have seen )are lithium, any attempt to recharge can result in fire, or explosion...so no recharging circuit....Have you done a BIOS update?

I havent tried that yet...will give it a go when i get home...ill bugger i up somehow though, i guarantee it lol

ok guys, bios flashed. Good news is that I left it overnight and next day and it started and didnt say bad checksum, etc.

Bad news is that it said something else that I didnt have time to read, then it said turn your system off then back on to get your system (or settings, cant remember) back...so I did, then had to go to bios and put settings in again...so bios telling me exact same as before, just in a different way, lol. will try again tonight and see what happens..maybe its because it was the first time I had turned off sincce ios flash and it didnt like it lol

Contrary to what was said above, the CMOS battery is recharged by the system. I can't say that this is true with all CMOS batteries, but I think that it is. If you have SpeedFan installed, the value Vbat is the voltage of the recharging circuit, not that of the battery. Even with a known good new battery, and with a sufficient Vbat voltage, the battery can become low due to poor contact in it's socket. If you have never removed the battery, it is not too likely that the problem is with the contacts, but if you have, it is possible that one of them was bent slightly, causing the issue.

Hi - I havent got speedfan installed..to my limited knowledge

I thought batts may get recharged as my last pc had one for its entire life (well over a decade) without having having a change.

It was out of this pc, however that I got the battery from for this one - thinking this problem was related to the old battery, I just took it out and replaced with the new one that came with the mobo, but still the same thing :)