new battery charger and battery arrangement

[eidiohir]

We finally got over to Belgium to see our boat. Because of the covid restrictions it has been nearly 2 years since we were last onboard. We were expecting a lot of trouble with the electrics etc but things were pretty good. However the battery charger, a Ctek m300, ran for a couple of hours then just stopped and shows no sign of life. I connected a backup battery charger but it was unable to charge up the batteries (2 x 160 amp lead acid for the domestic). I disconnected one of the batteries and the charger put the other up to full charge so I presume that the battery I disconnected was faulty.
Anyway, to get to the point. I need a new battery charger and batteries. I was thinking of a CTEK Automatic Charger M 25 and a maybe a lithium battery (they are so dear I wonder if they are worth it. I would like some pointers on both batteries and charger if possible. My pockets are not over deep but I am willing to pay as much as needed to have a good setup.

 

[Poey50]

A drop-in replacement lithium battery for boats is a simple marketing lie. A lithium battery system is a big step with large upfront costs and requiring a good deal of knowledge.

 

[Richard10002]

Why not keep using your back up charger, and get a matching 160A battery…. For now.

Going lithium is a big step and, given the cost, which includes the battery bank and other stuff to monitor and protect it, you should spend some time getting to know how it works, and what you really want/need.

 

[eidiohir]

Well I need a new charger and the new CTEK M25 will charge lithium batteries. The existing batteries are both more than seven years old and I think that the second battery will have a very short life. Also I was under the impression that you should not mix old batteries with new. Apart from that I don't know alot about battery arrangements.

 

[noelex]

If you are looking for another charger similar to the CTEK M25 the Victron Blue Smart IP65 chargers are worth considering.

Make sure your existing battery charger is defective before replacing. Some battery chargers will automatically shut down when they detect a battery is defective. They can sometimes give the impression they are dead until they are connected to a good battery with a reasonable battery voltage.

The best bank for the buck batteries for a house bank are usually the deep cycle golf cart batteries. These are 6v so two need to connected together in series for a 12v bank.

Batteries are expensive to ship so you need to search what is available locally.

 

[Poey50]

If you have lithium on your horizon, it is best to buy a fully user-configurable charger not one with a fixed lithium setting - the target voltage is almost always too high. I recommend the Victron IP22 Smart Solar 12/30. I have one - neat, versatile, not expensive and easily upgradable with new firmware releases. If serious about lithium I suggest you buy the cheapest lead acid 'leisure' that you can and spend the next years researching. One valid outcome is to find that you are better off staying with lead acid so you lose nothing by delaying.

 

[PaulRainbow]

Well I need a new charger and the new CTEK M25 will charge lithium batteries. The existing batteries are both more than seven years old and I think that the second battery will have a very short life. Also I was under the impression that you should not mix old batteries with new. Apart from that I don't know alot about battery arrangements.

I'd forget Lithium. Fit a pair of new leisure batteries of the same physical size and layout as the existing ones and a new Victron 30A charger. Blue Smart IP22 Charger - Victron Energy

 

[eidiohir]

I have had a quick at the Victron and it seems very good for the money.
I don't have a bee in my bonnet about Lithium it's just I want to put in the best that I can. I am quite happy to get two new leisure batteries and go on from there.