Relative newbie here so thought I'd just post up some info on my power tank that I recently finished.
Built around a Dewalt box that previously held my son's SDS drill (he gave me the box as he didnt need it!) and houses 2x Miady 32Ah LifePo4 batteries in parallel, giving just shy of 1000WH of power.
I changed to the LifePo4's from the original AGM 75Ah battery due to the enormous weight of the battery - the Miady batteries are incredibly light at around 4KG each.
Box has 2x cigarette outlets, one of which is power-regulated and boosted to 13.8V for the mount (AZEQ6). There is then both USB3.0 and USB-C as well as 2x Anderson Powerpole 12V outlets for future use. I also added a charger port, 20A breaker on the main +ve as well as a 6 way fuse box. On top of that I added a great find which is the power information screen. Lastly I decided to add 4 Red and 4 White LED sidelights and both can be switched independently.
Fairly easy to make and the batteries obviously the most expensive part at £119 each from Amazon. I've been quite impressed with the Miady batteries to date.
Without anything connected but all lights active and outlets active it runs 360-ish mA... I'm reasonable happy with that as the lights run at 250mA alone.
Should easily see me through a night in the field, away from home with DSLR, mount, 2x dew heaters, ASIAIR Plus (when it eventually arrives here in the UK from FLO - they are still preorder) and some other bits and bobs..