Solved BIOS resets everytime power is unplugged cmos battery replaced

So I have a machine I have just replaced the mobo on for someone but everytime it is unplugged from the wall upon reboot a message appears during post saying default values have been loaded and you have to press F1 to enter setup (bios) or F2 to continue.
I thought this was no big problem and swiftly replaced the CMOS battery but it is exactly the same, resets everytime power is cut
The board is an MSI B75MA-P45 and is brand new
Thankfully the default sata mode is AHCI so the machine still boots after reset but its really annoying me and the clock resetting stops WU from working and also threw a temp activation problem that was easily dealt with.

HWinfo does not show VBatt reading and speedfan does but reports 4.08V which is clearly wrong from a 3V battery

Any thoughts/ideas would be gratefully received as im running out of options other than an RMA which is going to be a major pain as this is her only computer and cant be without it

Just some thoughts.

***Why was the motherboard replaced??***

1. Is their a default jumper pin on the motherboard that is in the wrong position.
2. I have seen a power supply cause this problem.
3. Lately HWmonitor for other members has been giving wrong readings.
4. It has been know that a infection will monkey with the time so one can't get help on line.

If making the necessary changes to the BIOS and Accepting them or simply Accepting the defaults causes the same issue I'd get a replacement board as something with the battery not saving changes to the CMOS is not working as it should.

If a person works on computer fairly often it is good to have a loaner machine, I have both a Notebook and a Desktop for the purpose, both with Win7 and a Notebook with Win8.1. These are computers I have resurrected when the owners opted to get new with a warranty instead of spending upwards of half as much on a computer with no warranty, just wiser use of funds but then every situation is different.

I replaced the mobo as the old one was faulty, machine worked fine when I received it was only planning to do a case swap (as the old one was damaged) and an SSD upgrade but after moving mobo into new case it was DOA giving continuous beeps which indicated a power supply fault, tried different psu and no joy so I bought her a new board.
Reset jumper is not in place just two bare pins - machine does not reset bios on reboot only if unplugged from wall and I have swapped out the PSU for a different unit to be sure it wasn't causing probs on new board

I am thinking I may have to RMA it was just hoping someone may have an epiphany that could work
I am planning to pull the battery and test with a multimeter before I return it just to be sure though

I use a battery tester made for the purpose, tests several different types using leads or a socket for the CMOS type battery. I've found a multimeter does give a voltage reading which can be an indicator good or bad but doesn't put any kind of load on it, no sense of quality.

I believe the jumper that Layback Bear was referring to was the Clear CMOS or CLRTC jumper. Refer to the manual to find it's location.
There will be 3 pins and the jumper should be on pins 1&2. If it is on 2&3, or is missing completely, it could explain the problem.

You are correct TVeblen. That is exactly the jumper I was referring to.

If the battery is a "known good" battery that was replaced and still has problems, the only other thing is the motherboard itself.

With the power supply off completely (no keep alive voltage) it should still retain the CMOS memory settings. If its not doing it, and there is a good battery installed (and installed with correct polarity) its the motherboard.

New motherboards can be "bad". I had a new ASRock motherboard that 2out of the 4 memory slots were defective. ASRock replaced the motherboard.

Anything with a improper partial ground can also drain the battery.
Example:
A motherboard stand off in the wrong spot.
A case switch of some kind.

You could assemble the system outside the case to verify.

Thanks everyone for your input, I have tried again today with another new battery and its still the same
The system has been built out of case, everything double and triple checked, the clear cmos is just two pins that will reset when shorted and there is no jumper there at all.

I contacted the vendor today and they have kindly offered to send me a new board to replace it with which is great news so just a case of swapping them over when it arrives
I will mark this thread as solved as there really is nothing more to try

Thanks again everyone for your thoughts

Your welcome Paul.
Double check the motherboard manual for the jumper proper position.

Sounds like a good solution!

I wonder if you are missing a jumper?
The manual makes it sound like there is one.