This size of pallet truck?
ebay.co.uk/itm/Fully-Electr … Swq4tfh1q5
No need for a huge battery warehouse type truck if only doing odd deliveries. We have these types in some of our rigids. Recharge through Anderson lead in load area. You will need a proper split charge system of course, so that the charging only happens when the vehicle batteries are in a a good state.
If on an artic trailer there is an issue with thick power leads remaining connected when driving and manoeuvering but there are ways and means to overcome this.
Or, thinking differently, and depending on needs etc, fit a smallish 240v genset in a pallet box or similar under the trailer? Mains power into the load bay to recharge most anything.
Solar panels on trailer roof? The green solution! (Not sure about tree damage though)
Edit. If frozen goods, drop handle on pallet truck and store that in pallet box too. Cold temps and batteries are not a good mix.