In last 1.5+ years bit more than a dozen of X299 Dark mbs went through my hands. They were purchased/obtained at various times from various places, some of them had serial # starting with 18 (indicating 2018 as year of manufacture), some with 19, and one I received from EVGA as RMA with 20.
 
After I became aware of issues with CMOS battery I made it a habit to replace EVGA’s one with brand new one as very first step. I haven’t kept notes on voltages for all of EVGA’s at time of replacement but here are notes for 7 of them in no particular order:
 
0.00V
0.02V
0.09V
0.17V
0.24V
3.09V
and last, but not least, 0.04V (this one I get relatively recently as RMA replacement by EVGA for one of my X299 Dark’s).
 
In other words:
 
1. Out of 7 I have data for not a single one arrived with good battery. That combined with fact my boards came from various places at various points in time enough apart from each other makes one feel EVGA didn’t have issue with small batch of batteries, that issue was (very?) widespread. Either that or something is draining them much faster than they should be.
 
2. At least two of these came from motherboards that had firmware chip with red dot on it. It is my understanding red dot indicates chip EVGA replaced after Cascade Lake X came out, which means sometimes in beginning of 2020. If that is correct that makes one feel EVGA had mb in their hand for chip replacement yet didn’t use that opportunity to replace battery even though they knew by then there is a question mark over batteries.
 
3. That very last battery, one that came dead in recent RMA, is most upsetting one. Receiving that makes one feel as if EVGA doesn’t check whether replacement actually passes all quality checks and works as it should before sending it to customer.
 

rjohnson11
For this query I suggest you call EVGA tech support.

It is not a query/question, it is a statement of my findings I am sharing publicly with a community in hope community might have a benefit from them down the road. I have already contacted EVGA and asked to talk with product manager to discuss this and other observations I have. I am waiting for a call back.

 
 
check this thread
 ok
can not link thread, sorry
 
edit again:
 
bought x299 dark in 2019 i think, arrived with dead bat. there is a thread here about cmos error with lots of info
 

Mister E...
FYI, the CMOS battery on my x299 Dark was also dead - the board had sit in the box a while before being put to use, but these batteries should typically last 10 years (and the board shouldn't be pulling that much current from it - unless there's a defect).
…
I do have concerns of dead batteries going bad/leaking …

 
I’m not concerned that dead battery could leak as things nowadays seems to be good enough that I don’t remember when was the last time I’ve seen run of the mill CR2032 battery leak.
 
What I’m really concerned about is exactly what you too mentioned as possibility, that something might be draining battery because these batteries are supposed to last up to 10 years. And all data so far indicates to me this is -NOT- due to isolated batch of batteries.
 
Possibility of that upsets me. Some of my systems with X299 Dark in them need to stay off the power for as long as months until they are needed and due to what is (in my opinion) poor design CMOS battery on them can’t replaced without completely tearing system apart which would be a pain in the back, especially with water cooled system.
 
It also upsets me that RMA replacement motherboard ships in such condition. In my opinion it is not acceptable (from customer standpoint) that RMA replacement is shipped in condition that doesn’t work out of the box and requires further work on it by customer.