D500 battery life on long exposures

[Peter Connan]

I know there has been a lot of discussion about the D500's battery life, especially with the older Li-Ion-01 batteries.

I have found that my D500 gives pretty good battery life under normal usage, and very good battery life when shooting action images with limited or no image review, but that battery drain increases with heavy use of the LCD screen. This was not unexpected.

However, I have recently found that mine really eats batteries when taking longer exposures. It gets less than 80 30-second exposures on a fully-charged battery, irrespective of whether it is an Li-Ion-01 or -20. This is with a cable release and also with interval timer and in time-lapse movie mode.

A battery grip would seem to be the best answer, but is far too expensive, especially when combined with the EN-EL18 battery, but I need to get up to 200 such exposures without AC power being available. Also, replacing batteries is not an option as my tripod's base covers the battery compartment door.

My questions are:
1) Has anybody here used the D500 for long exposures, and if so what has your experience been?

2) Has anybody here experimented with external power solutions? Can one supply the camera with power from a 12v external battery, regulated down to 7-9 V, or will the camera give an error?

[Seapy]

Is your long exposure noise reduction turned on?  (If thats applicable on a D500...) That can eat batteries.

[Peter Connan]

No, that is turned off Seapy.

[Øivind Tøien]

While it is normal that long exposures takes more battery power, 80 30 sec exposures sound low. With my D7100 I can get about 120 60 sec exposures + initial test exposures and time with live view for focusing and aiming at temperatures between -10°C and -20°C, live view active for 3 sec between exposures (for mirror up) and released with external wired remote.

[golunvolo]

I’m using a third party grip from bh and it works very well. It will at least solve the change of batteries when in the tripod for around 80 usd.

   Edit: Vello BG-N17 Battery Grip for Nikon D500 for 89.90

[Peter Connan]

Thanks guys.

I forgot to mention, those 80 shots were not in live view, although i used live view to focus the first shot and briefly reviewed the first 4 or 5 to confirm framing. Temperature was between 20 and 30 C
 
The D750 gave me in excess of 150 shots under similar conditions.

[Peter Connan]

I have discovered something, and a friend has corroborated it by testing on his camera:

When shooting 30-second exposures at base ISO, battery life is reasonable (250-350 exposures). But increase the ISO to over 2500, this drops to under 100 exposures.

Both long exposure and high-ISO noise reduction was turned off during these tests, and freshly-charged Li-Ion-20 batteries were used.

Can anybody shed some light on the reasons, and more importantly, come up with ideas to reduce the battery drain under these conditions?

[Akira]

If I remember correctly, Nikon has been applying the high-ISO noise reduction as default at the higher ISO settings.  This process cannot be turned off by the user in the menu.

Would that function be activated when the ISO is set past 2500 and increase the processing power?

[Peter Connan]

I don't know, but since there is a menu setting of "off" for high-ISO noise reduction, I would have thought that strange?

[Akira]

I don't know, but since there is a menu setting of "off" for high-ISO noise reduction, I would have thought that strange?

Actually, no.  Aside from the "usual" high ISO noise reduction that can be turned on or off in the menu, there is another noise reduction that is permanently on.

[Øivind Tøien]

Actually, no.  Aside from the "usual" high ISO noise reduction that can be turned on or off in the menu, there is another noise reduction that is permanently on.

The NR settings with high ISO NR off on the camera can be checked in CNX2 or CNX-D: With my D7100 at ISO 800 it is 0, at ISO 1600 4, ISO 2500  5, ISO 3200 6, and at ISO 6400 8. At NR setting low the values are about 2x this. The NR type is faster. Perhaps someone could check if D500 deviates strongly from this? Later bodies might use more CPU intensive algorithms.

However when shooting raw only, the CPU use for this would only be to create the embedded JPG preview. And why would NR use more CPU for a long exposure than for a shorter one?

[Akira]

The NR settings with high ISO NR off on the camera can be checked in CNX2 or CNX-D: With my D7100 at ISO 800 is is 0, at ISO 1600 4, ISO 2500  5, ISO 3200 6, and at ISO 6400 8. At NR setting low the values are about 2x this. The NR type is faster. Perhaps someone could check if D500 deviates strongly from this? Later bodies might use more CPU intensive algorithms.

However when shooting raw only, the CPU use for this would only be to create the embedded JPG preview. And why would NR use more CPU for a long exposure than for a shorter one?

Thank you for confirming the noise reduction at work.  I've assumed that this particular noise reduction is applied rather on the hardware level and is different from that of the usual one for the JPEG files.  I'm not sure if this is correct or not...

[Les Olson]

It's snowing and miserable, so what can you do but an experiment?

I took a fully-charged, age 0, EN-EL15 type 20; the D500 said it was 94%, the D7000 said it was 96%. I took 30 second exposures, with long exposure NR off; ISO was 100; capture was RAW, manual shutter press, AF off.   

After 10 exposures the D500 said the battery was at 95%, after 20 92%, after 30 90%, after 40 87%, after 50 84% and after 60 81%. In the D7000 the battery read 86%.  After 70 exposures the D500 said the battery was 77% and the D7000 said it was 84%.  After 80 exposures the D500 said 74% and the D7000 82%, then after 90 71% vs 78%, after 100 67% vs 75%, after 110 64% vs 73%, after 120 61% vs 71%, after 130 55% vs 67%, after 140 52% vs 65% and after 150 exposures 48% vs 61%.

So, as exposures accumulate, the apparent battery drain per 10 exposures in the D500 is probably the same, although it might be increasing slightly, from 2-3% of the charge at first to 3-4% after 150 exposures.  Why that might be I do not know.  The D7000 clearly recorded more charge at all the levels tested, and the gap between the D500 and the D7000 increased as the number of exposures increased, from 5% after 60 exposures to 13% after 150. 

I put another fully charged battery in the D7000, where it read 95%; the same battery read 92% in the D500. Settings were the same as for the D500 trial.  After 10 exposures in the D7000 the battery read 93%, after 20 92%, after 30 90%, after 40 88%, after 50 87%, and after 60 86%. At that time the battery read 80% in the D500 and I stopped. 

So there seems to be no big difference in power use per exposure in the D7000 and D500: after 60 exposures the battery read the same whichever camera it was used in.  The D500 consistently reported less % charge than the D7000 at the same level of charge, and did so to a greater degree as the charge declined, so that seems to be the main cause of the reduced effective life.

[elsa hoffmann]

the battery drain between different models is also discussed or demonstrated here https://nikonrumors.com/2018/02/24/nikon-d500-batterygate.aspx/

However - I still would like to see more of the results of  low vs high ISo as peter reported. I dont find any reports (yet) and this on the web

[Les Olson]

If it keeps snowing/raining I may be bored enough to do it tomorrow.   

It seems clear from a lot of measurements that the guts of the issue is not power consumption, but the D500's notions of how much of the remaining power it can make available to the user vs how much it needs to keep in reserve.