Solar wiring/power issue

[petery27]

I have a Renogy 300w triple solar panel setup on my crafter van.
It feeds to the batteries via an mppt controller. Have 3 power line 110ah leisure batteries in the van all the same standard wet type battery all linked in series but the solar doesn’t seem to be able to put anything back in to the batteries at all. Seeing 260w to 300w on a sunny day and the history is saying it’s producing over 1400w on a sunny day.
All the batteries are within 6/7 months old and I have a battery maintainer fed from 240v on them when plugged in to mains. Which recharges the batteries fine and they are then able to cope for a couple of days so I believe the batteries are fine as they don’t die immediately.
The item that has been running in the van is a small fridge that works on 24/240v.
Due to go away in the van this weekend so I have had it unplugged while the weather is good and the batteries have run down over 4 days to being at less than 10v overnight. No other draws on the battery I can fine.

Am I doing something wrong as I expected the setup I have to give me a few days of not having to hook up to mains and be able to power the fridge lighting and charge phones without issue.
Does anyone have a basic wiring as to how I should hook it all up or am I expecting too much out of solar.

[Mr Pointy]

It might help if you post a wiring diagram & the model of controller. Who designed the installation? Are you sure the batteries are in series as that would give you 36V.

Edited by Mr Pointy on Tuesday 3rd June 09:41

[ATG]

(the leisure batteries are in parallel rather than in series, surely?)

[petery27]

Sorry meant parallel

[ferret50]

Reads like a fault between controller and batteries to me, breaker or fuse intact?

[petery27]

I’ll check that and see if I can read a voltage coming out the controller see if it alugns with what it’s telling me