Battery Power

[Grimaud]

In our first season with our Princess 39 we found that running the galley fridge and cockpit cooler was not possible without running the generator almost full time. With only the fridge on we still had to run the generator for 4 hours two to three times a day. Does anybody with a Princess 39 have a similar experience?

 

[jrudge]

I suspect your batteries are dud. We had a t40 so sim size and run the gen once a day.

 

[Xlantic]

Something is not right. What is the capacity(Ah) of your house battery bank? What type and how old are the batteries?

 

[Grimaud]

The drop test showed following Amps in batteries
A=703A
B=718A
C=701A
D=693A

 

[henryf]

Fridges do use a lot of battery power but I wouldn't expect to have to keep running the generator as you are.

When you got the boat there should have been a flight case full of handbooks for all the hardware fitted. Dig out the ones for the fridge and chiller, they should list the low voltage power consumption.

I'm assuming you don't have an inverter fitted and the units are trying to run on 240 volts through it. That would knock hell out of the batteries.

Check the fluid levels in the batteries to make sure they aren't low. Check each individual cell.

Assuming you have the boat on shore power all the time was the drop test done with the batteries fresh off charge? If so it might be worth turning the charger off, isolating the batteries via your domestic solenoid switch then leaving them for a day or two and repeating the drop test.

Have a look at what else is running off the batteries as well. Whilst you are concentrating on the chiller units having all the lights on and other items powered up could be the problem.

I think I'm right in saying your boat has a current meter fitted to the isolating panel which shows low voltage (and high voltage) current draw. Have a look at that to see what it says.

If we are on battery power for any length of time I tend to not run fridges. I make sure the doors are kept closed (as they would be anyway) and use the cold stored in them. The fuller they are the more cold they store. Running the generator for cooking, drinks, hair straightening and preparation throughout the day tops up the cold stored in the fridges, freezers, chillers etc.

Henry

 

[Momac]

I have 33ft boat with one 12volt fridge - of the usual modest size. Two domestic batteries.
We have stopped 48 hours in the UK summer and there is remaining energy in the batteries sufficient to start the starboard engine.
Therefore the performance you are experiencing is clearly not normal.

Could be there is a big voltage drop between the batteries and the fridge. Some fridges will cut out as the voltage from the batteries falls but the voltage drop could be larger than it might be due to corroded cable, corroded connection, faulty isolator switch or simply the wires too thin. .

.

 

[henryf]

I have 33ft boat with one 12volt fridge - of the usual modest size. Two domestic batteries.
We have stopped 48 hours in the UK summer and there is remaining energy in the batteries sufficient to start the starboard engine.
Therefore the performance you are experiencing is clearly not normal.

Could be there is a big voltage drop between the batteries and the fridge. Some fridges will cut out as the voltage from the batteries falls but the voltage drop could be larger than it might be due to corroded cable, corroded connection, faulty isolator switch or simply the wires too thin. .

.

I don't think that would cause the problem, it might mean the fridge didn't work which would result in no current drain at all.

Given the age and model of boat I would be very surprised if inadequate cabling had been used. The wiring on these things is a work of art

Henry

 

[alt]

I didn't read the other replies, so forgive me if i'm repeating...

On our 37ft boat we have plenty of LED lights, 2 fridges (although normally only 1 running), electric heads (1) and use the water pump quite often.

We already had an isolator switch etc. installed, so when we bought the boat we just needed to beef up with fresh batteries.

We have the following:
1 x Starter Battery (1 Bank) - 130Ah
2 x Domestics (1 Bank) - 130Ah x 2

After research / trial & error etc. we found that it wasn't just the Ah that was important, but to find batteries that fit the bill. We ended up purchasing GOLF CART BATTERIES. Think about it... these things are charged up, drained throughout the day, charged up etc..... - basically a similar life-cycle as on a boat.

When we get to our destination, we switch over from 'both' to 'domestic' bank. To date, I have never had to switch over to 'engine' to start the engines the next morning, but it's good to know that it's there if needs be. We have been doing this now for 3 seasons on the same batteries, no problems!!

As said above, I suggest your batteries are knackered. The batteries we bought were not cheap, but well worth it (about 300 euro each). I will try to dig out paperwork and find out what batteries I have.

 

[Xlantic]

In our first season with our Princess 39 we found that running the galley fridge and cockpit cooler was not possible without running the generator almost full time. With only the fridge on we still had to run the generator for 4 hours two to three times a day. Does anybody with a Princess 39 have a similar experience?

But why did you have to run the generator so much?

Fridge and cooler stopped working? (This could be a voltage drop as MartynG suggests.)

Batteries discharged? How do you measure this? Voltage?