its a really good pump we have had ours ten years or more .Inside is a small sealed acid battery available from Ebay (the measurements have to be precise to fit,ours lasted 8 years).
our chargers wire broke right at the box so we use a 6v DC 500mA PSU (centre +) i had in the shed ,a 6V 1 amp etc would be fine so long as the connector fits the pump and the centre of the connector is positive
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets