A7II NP-FW50 dummy battery causes internal date and time to reset

[SnikwaH]

I tried using a dummy battery to power my A7ii for a variety of uses, but whenever I switch from my regular battery to the dummy battery and vice versa, I am prompted to set the date and time.

I have 2 regular batteries and switching between them is completely normal.

Dummy Battery: it asks for 5V 2A or more.

I have tried my USB power bank, and my wall charger. both have the camera fully functioning, but both have it reset date and time.

The USB power bank outputs 5V 3A, 9V 2A, or 15V 1.2A. the wall charger outputs 5V 3A or 9V 2A.

Anyone have this issue or know what the problem might be? i have tried searching for others who have had this problem but i can only find 1 person in the reviews for this product who have experienced the same thing. would a 5V 2A charger maybe work better than the 5V 3A?

[VTC]

Had the same problem but it wasn't the dummy. Mine FIRST started with the dummy but soon migrated to EVERY battery swapped out. Lived with that massive inconvenience for a year before I sent the camera in for repair of a wonkified menu system.

Though there's no user swappable memory battery there must be an internal one that keeps a wee amount of power keeping things charged when the battery flatlines.

[SnikwaH]

interesting... maybe my a7ii was produced a while ago and since I bought it a bit less than a year ago its not holding its charge well?

I've seen lots of comments about peoples a7ii, a7rii, and a7sii not holding an internal charge with regular batteries when swapping.

might then ask about a replacement under warranty? I don't want to pay for it lol. I plan on getting the a7iv when it comes out anyways.

[XKAES]

You should check your manual -- in the battery and troubleshooting sections.  These cameras have internal batteries to keep TIME and other details saved in memory.  Just like a computer when the CMOS battery is dead, you will have problems.

In my manual, it recommends leaving the camera OFF with a fully-charged battery (or AC adapter) overnight.  That MIGHT recharge the internal battery.  If it doesn't, it probably needs to be replaced.

So check your manual -- the FINE print.

[SnikwaH]

9 minutes ago, XKAES said:

You should check your manual -- in the battery and troubleshooting sections.  These cameras have internal batteries to keep TIME and other details saved in memory.  Just like a computer when the CMOS battery is dead, you will have problems.

In my manual, it recommends leaving the camera OFF with a fully-charged battery (or AC adapter) overnight.  That MIGHT recharge the internal battery.  If it doesn't, it probably needs to be replaced.

So check your manual -- the FINE print.

i just went through the manual and i understand how it works. regular batteries keep the internal battery charged when swapping. but as soon as i plug in a dummy battery, the internal battery seems to discharge so it loses date and time.

i keep a full battery in my camera every night so i know the internal battery gets charged.

[SnikwaH]

i have also just found that if i plug in USB power via the micro usb port, then insert the dummy battery and turn on the camera, the internal battery keeps its charge. i can then unplug the micro usb power and it will work normally. its then fine to swap to a regular battery.

so something about when plugging in a dummy battery by its self sets off the internal battery