Leisure battery-Not holding Charge

[LambertT5]

Hi Forum,

I am after some advice re my leisure battery. After some weeks of none use my main battery died(which is now sorted) but used the camper this weekend and the leisure battery doesn't seem to hold a charge anymore. Had it plugged into mains for a day prior and died after about 2hrs once on site.
Be greatfull for advice on next steps for troubleshooting, or should I just replace?
Is it possible to fit solar to my setup out of interest?

 

[Pewt]

How old is it ?

 

[Dellmassive]

You can test the battery yourself with a 12-volt car battery tester.....

https://amzn.to/4u5Yhdy

 

[LambertT5]

How old is it ?

Battery's around 3 year old I think.

 

[Pewt]

About what mine lasted without too much heavy use. Excuse to go lithium.