Or is OEM the best way to go?

I have got this for my 7D mk2, seems as good as the Canon ones and at half the price. https://www.amazon.co.uk/gp/product/B01GPUNYE2

Camera is picking them up and will show battery status which does not work on many of the cheaper ones.
Have had some even cheaper ones but they all failed quite quickly as well as having the issue mentioned above.

From about four years ago, I’ve had a couple of non-genuine Nikon batteries that last OK, and four that last about half as long. One of the better ones expanded slightly shortly after I first used it, but it still works the same as it ever has. None of them last long enough to be serviceable in video mode; OEM only for that.

I’d buy OEM replacements as I know what I’m getting; non-OEM is a lottery. I’m also slightly uneasy leaving them on charge if I’m not around.

I’d buy OEM replacements as I know what I’m getting; non-OEM is a lottery. I’m also slightly uneasy leaving them on charge if I’m not around.

This +1. Have played the non-OEM lottery with varying success with my Nikon cameras. Some worked fine, some had no longevity at all.

I’d stick with OEM batteries.

I use ExPro batteries in my cameras – either direct or through their amazon shop. Very good, life at least as good as the originals, in some cases much better (for my Sony!)

+1 for Expro.
I’ve had a couple of their their for two different camera. Seem to give similar life to the OEM ones.
The second one I purchased seemed to have swelled before I used it, so a replacement was sent with no hassle.

OEM or Duracell in mine – 350 and 5D.

What’s a “SLDR”?

Its a high end typo.

Is it a crop or a full frame typo?

Another +1 for ExPro here

I think Hama are pretty well known for replacement batteries for SLRs.

Mymemory seem to do them, as well as Duracell ones:

https://www.mymemory.co.uk/photo-video/photo/camera-batteries.html

I’ve had reasonable success with Hahnel over the years