I’ve swapped out the pump on mine for a backpack pump. You can get a 4-5Lpm one on eBay for about £10. Don’t get one rated higher than 100psi though. You can then use a Yuasa or similar 12v 10ah battery which will give you a days use on a full charge.
This will make your trolley considerably lighter. I’ve been running mine like this for around 3 yrs.
If weight is not an issue for you, any golf cart battery rated as 12v 24-26ah will do