For reasons that totally escape me Nikon does NOT provide a standalone battery charger with the Nikon P900. Yes, the P900 has an internal battery for its clock but that alone is not a good enough reason not to skim on a $4 charger.
I have never liked charging batteries INSIDE the camera. It is so limiting in that you can’t use the camera while the battery is being charged.
Given my penchant for taking upwards of 900 pictures on some days I can easily go through 3 charged batteries within 8 to 12 hours. So I tend to carry 3 to 4 charged batteries on me.
So, yes, I got chargers for the Nikon P900 even BEFORE I picked up the camera — and yes, that was in the plural.
I had never had one of these DUAL chargers and they make SO MUCH sense for me given the batteries I have to charge. Being USB only is not an issue since I have USB charging stations all over the house! So why do I need two chargers? One to go in the camera bag — of course.
Up until I got my now traded-in Fuji X-E2s, in May 2016, I used to be “Wasabi” only when it came to extra camera batteries. Then, with the Fuji, I saw posts for the “DOT-o1” batteries, with extra “charge”, on Amazon. There prices were good. I got a set of 3 for the Fuji and they did fine. No problems. Though I never counted the shots I think they gave me more shots per battery. Worst case, they were no different to the original Fuji battery or the two “Wasabi” batteries that I also bought.
With the Nikon P900 I did NOT bother getting any “Wasabi”. Just ordered the four “DOT-01” batteries. I have already used two of them. No issues.
So, for now, I have to say that the “dual charger” and the “DOT-01” batteries work just fine with the Nikon P900.