Battery charging

The Ctek charger is smart and it doesn't like charging dead flat batteries.

If the "Old Style" charger has raised the voltage of the batteries you could try plugging the Ctek in again and it may well work!

All of these smart chargers have problems with batteries in other that perfect condition....

You may stick some charge into ya batteries with a plain old dumb charger ........ but if they are buggered, they are buggered.

If you don't have a battery load tester, battery analiser, or a carbon pile ammeter .......

Charge the batteries up as best you can however you can, if they have been hammered it may take a couple or 3 days for them to come back up.

I hope you have an accurate voltmeter.
Then take them off charge .... leave them rest for at least an hour..... measure the voltage.
over the next week, check the voltage every day ...... if it drops much below about 12.3ish volts .. with no load ..... no. its not good

finally load the battery up with a headlight or spot light or such ....... if the voltage drops below 12 volts ...... its not good.

If they are 4 years old and they have been hammered ..... they are probably buggered.

just go and buy some new ones.

cheers

Notso is correct re a smart charger not recognising a dead flat battery.
However, your 5 amp charger is way too small for practical charging of your 180Ah battery bank. It would take ages.
Rule of thumb is an current rating of 25% of total Amp hour rating, so you could go as high as a 25 amp charger, but a 15 amp charger is much cheaper and will perform well.
I have a 15 amp Ctek Charger in my Camper, to support a 200Ah battery bank.

Worth getting your batteries load tested to see if they are recoverable, but you need to attempt charging them first.
A dumb charger will suffice to initiate the charging process until a reasonable charging current has been applied, but a smart charger with a multi-stage charging process is still the best for the most efficient and effective maintenance of your camper batteries.

Gronk,

I don't disagree with your comments but look at the practical aspect.

An onboard charger needs to provide more charging current while stationary than what is being drawn.
With the OP having 180ah of storage, one would assume there is a heavy current drawing device, such as a compressor fridge, in the equation.

My advice is simply based on practicality and personal experience.

My setup also incorporates a dc-dc smart charger to maintain a healthy 12v charging regime when driving and solar input when away from 240v supply.
A 5 amp charger won't cut the mustard trying to put back enough current, when "on the road".