This battery and charger set is excellent value for money.

It includes 2 NP-FZ100 batteries and a 'fast' (see below) charger for (at the time of writing) under £60. Considering an original Sony battery costs over £60 each, that's one amazing bargain.

I tried both batteries in my Sony A7IV battery grip and both registered with no issues straight out of the box with 56% charge showing.

I did not initially charge the batteries as I wanted to show in the video that they work straight away, but it's always advised to fully charge the batteries before the initial use.

The charger, when plugged in (the charger has inputs for both Type C and Micro USB, meaning you shouldn't be caught short when away from the home) flashes the LCD showing the battery capacity upwards in a charging motion style before a full charge indicator is given. I did however find that the charger took a few hours to charge the batteries, despite them already being half full. So I wouldn't say it was a 'fast' charger, more an overnight one.

The K&F batteries are both a larger capacity with the original Sony battery stating 2280mAh and the K&F is 2600mAh in capacity, so this should mean you get a few more shots of usage out of it.