In general, the incidence of faults on Vue units during their first year of production/sales has been encouragingly low. I don't have exact figures to hand but a level of 5% is probably realistic, which is actually very good for the period when a brand new design is released into the field.
The only two types of Vue fault that seem to have been reported with any frequency are - coincidentally - both low ISS battery warnings. I'm pretty sure that these two types have quite distinct causes although because the initial symptom is the same there's obviously a tendency on forums like this to confuse the two and to lump them together.
The first type is a genuine but premature low battery warning, ie when the old battery voltage is checked it's found to have been fully depleted. The incidence of this fault variant is very low - maybe 1-2% - and this is the type that can be fixed by the gel application to the contact pads. A change in production method to prevent this fault was made some 6 months or more ago, ie not long after the first reports of the problem came through and Davis had a chance to investigate the cause in faulty units.
The second and quite separate type are spurious low ISS battery warnings. When the ISS battery voltage is checked on these, the battery is still found to be in good condition and so the warning of low voltage is inaccurate. This type of fault will often clear itself along with other system resets and clear operations at midnight each night. So this type of fault is a minor operational nuisance but nothing more. I haven't seen a detailed write-up of the cause but it seems likely to me that the microcode monitoring the ISS battery is a little oversensitive on a minority of systems, which is presumably also something that can readily be fixed in production. I understand that a new console firmware update to counter this spurious low battery problem is in testing.
Well I've also been having the infamous "Low Battery Warning" on my ISS and after reading all the previous 7 pages of this thread, JohnD's Post (above) is by far the most informative.
Paraphrasing:If you're getting the problem on a new system, the best thing to do seems to be to first check the battery voltage.
If it's over 3 Volts then you're good and you don't need to worry too much apart from check that the green LED under the ISS isn't always flashing or is constant. Keeping an eye on it and checking the ISS battery voltage every week or so wouldn't hurt.
If the voltage is under 3V or the green LED is flashing/constant, then you should do a full reset on the system. If the green LED is on or flashing after more than 5-10mins of the ISS being on, check the white sync button isn't pressed in.
One of the next best steps seems to be to apply a dielectric grease (if not already done in manufacture) to the 3 pins under the ISS battery (especially in a highly humid/wet environment).
After this, reset the ISS by removing the old ISS battery over night then replace the battery in the morning. At the same time, reset the Console by holding down the DONE/SETUP button after you power up the ISS.
Sometimes the message disappears after midnight and doesn't re-appear. If it still appears after the above, then you really are best to talk to Davis.