Lithium batteries

[David Mack]

2 hours ago, Tonka said:

And are your crimping tools the correct ones and calibrated regularly?

The cheap hydraulic crimping tool I bought on ebay makes absolutely fine connections, but you have to use dies marked one size smaller than the cable you are crimping!

[Memories]

I ain't doing mine.

 

Electricity is not to be messed with, leave it to the professionals.

 

I wouldn't have the knowledge to even attempt it to be honest.

[jonathanA]

18 hours ago, David Mack said:

The cheap hydraulic crimping tool I bought on ebay makes absolutely fine connections, but you have to use dies marked one size smaller than the cable you are crimping!

 

And then cut off the sharp "ears" they leave.... 

[GUMPY]

16 minutes ago, jonathanA said:

 

And then cut off the sharp "ears" they leave.... 

Before covering the mess with adhesive heat shrink 🫣 

[Jen-in-Wellies]

42 minutes ago, GUMPY said:

Before covering the mess with adhesive heat shrink 🫣 

It's what the pros do. 😀

[David Mack]

1 hour ago, jonathanA said:

 

And then cut off the sharp "ears" they leave.... 

It doesn't produce significant ears if the crimp terminal is the right size for the cable. It's just the dies that are mislabelled.

[jonathanA]

2 minutes ago, David Mack said:

It doesn't produce significant ears if the crimp terminal is the right size for the cable. It's just the dies that are mislabelled.

Not in my experience  and that of many using the cheap far eastern hydralic crimpers. The dies are simply poor quality rather than being mislabelled. 

 

Same terminals, same cable in my proper crimper terminate perfectly.... 

[GRLMK38]

19 hours ago, jonathanA said:

Not in my experience  and that of many using the cheap far eastern hydralic crimpers. The dies are simply poor quality rather than being mislabelled. 

 

Same terminals, same cable in my proper crimper terminate perfectly.... 

Which one do you use?

[jonathanA]

9 hours ago, GRLMK38 said:

Which one do you use?

Something like this think mine does 6 to 90mm

 

https://www.tlc-direct.co.uk/Products/BHMK8.html

 

I have one of the ebay hydraulic ones too and for the money they are OK but as noted you often have to go down a size to get a good crimp. Handy when space is restricted. 

[Memories]

On 28/02/2026 at 22:09, Tony Brooks said:

 

You should know the voltage and capacity of your existing system, if you have 24 volts or are using 6v batteries then it gets a tiny bit more complicated, but you need the same nominal voltage as the existing system, and if you get the same total capacity it will be more than adequate, possibly rather more than you actually need, but that just means you can go longer between recharging.

 

If you don't know the battery capacity post a photo of them so we can work out how they are connected together (series, parallel or series parallel), you don't need to worry about that, we will tell you, and if you read the capacity in Amp hour (Ah) on the labels we can tell you the total capacity. 

 

My advice is to look for what is known as "drop in" 12V lithium batteries, rather than individual cells. I get the impression that Frogstar batteries seem to have a fair name on the forum, unless you want to pay for Victron.

I had victron charge controller in already so just went with an upgrade, the solar and batteries are in and up and running.

 

The pressurisation of the accumulator didn't work

 

 

I maintain that the leak is somewhere on or around the calorifier tank. Still getting two Titan vacuum buckets everyday. The water is always under the tank.

[Tony Brooks]

3 minutes ago, Memories said:

I had victron charge controller in already so just went with an upgrade, the solar and batteries are in and up and running.

 

The pressurisation of the accumulator didn't work

 

 

I maintain that the leak is somewhere on or around the calorifier tank. Still getting two Titan vacuum buckets everyday. The water is always under the tank.

 

Please do not mix topics. This one is about swapping to lithium batteries, specifically LFP batteries because of their safety.

 

Also, please be specific. If by tank you mean calorifier then please say that. WE don't know your bat and just the word "tank" could be an engine expansion tanks, central heating expansion tank, or the calorifier - even possibly the fuel tank, although that is very unlikely in this case.

 

But to answer you comment about the leak, I don't see how you will find it unless you can narrow the area you are looking in. For that you need to clean and dry the bilge so when you cover the whole area with blue, news, or kitchen towel it won't soak up water from below. that means that damp patches that appear but be below or close to the leak.

[ditchcrawler]

24 minutes ago, Memories said:

I had victron charge controller in already so just went with an upgrade, the solar and batteries are in and up and running.

 

The pressurisation of the accumulator didn't work

 

 

I maintain that the leak is somewhere on or around the calorifier tank. Still getting two Titan vacuum buckets everyday. The water is always under the tank.

Are you living on the boat, if not turn the water pump off and see how much water you collect in a couple of days.

[Memories]

17 minutes ago, ditchcrawler said:

Are you living on the boat, if not turn the water pump off and see how much water you collect in a couple of days.

I am living on the boat, but I did have the pump off for about a week while I was sorting out the leak in the bow, which was from a couple of speedfits on the boiler water inlet pipes.... I was taking less water out than now, but that could have been the water draining through to the stern from the leak in the bow so not definitive.

[Tony Brooks]

8 hours ago, Memories said:

I am living on the boat, but I did have the pump off for about a week while I was sorting out the leak in the bow, which was from a couple of speedfits on the boiler water inlet pipes.... I was taking less water out than now, but that could have been the water draining through to the stern from the leak in the bow so not definitive.

 

and that statement raises the question of a rear bulkhead again. It is important as it helps isolate the area of the leak. 

 

Is there a steel bulkhead, sealed to the hull sides and the baseplate in front of the engine. 

 

If there is then any leak at the front of the boat will build up on the front of the bulkhead.

 

If there is not then any leak at the front will drain, possibly over a bit of time, right to the back of the boat.