Thanks spruce ,
Maximum draw of my aquatec is either 7 or 9 amps , hard to find accurate info .
I will go for the 150ah I think 👍
Probably a good decision. The thing is that Splash and Dash also has a couple of electric reels and two operators on his van. So a bigger battery will be more than ample for you. He doesn't have a battery with a heat blanket, so in winter his battery charging has to be done when he gets home as is van and battery are still warm. I do the majority of my battery charging with my van's alternator. This means that I get very little battery charge in the winter morning commute as my battery is below 5 degrees and that initial charge is going into warming the battery up.
When I purchased my Sterling B2B charger, I also purchased a Victron Battery monitor. I used that live data to understand which equipment was drawing what current.
(I purchased the Sterling unit as I believed the sales hype that this would charge my leisure battery up to 5 times faster that an ordinary Durite 140 amp clone split charge relay. It didn't make any noticeable difference. A leisure battery has a high internal resistance. The fuller the state of charge, the higher the resistance. Because of this increasing resistance with the increasing state of charge, the battery accepts less and less charge. I found a 110 amp leisure battery would only accept a charge of 2 amps with a 95% state of charge.)
I also found that the same pump and controller used less current pumping water through 100 meters of minibore when compared to the same pump and controller pumping water through 100 meters of microbore.
The pumps also draw a little less current when the diesel heater is working and the water is hot, but this is more difficult to put a figure on.