Princess 35 batteries- 240v system

[evilspear]

Hi all, should my 1988 princess 35 run my 240v system while the engines are running. At present they don't. Am i missing something.

 

[Sticky Fingers]

An inverter is required to turn 12v or 24v from batteries into 240V. So to answer your Q, yes - you’re missing the inverter and its associated wiring. Simpler to have one or two dedicated sockets fed by solely the inverter rather than trying to plumb the inverter into the boat's wiring, but both would be possible. Note that you may well also need to beef up your battery back significantly.

Alternatively, you need a generator.

 

[PaulRainbow]

Hi all, should my 1988 princess 35 run my 240v system while the engines are running. At present they don't. Am i missing something.

As per post #2, you need an inverter to run 240v systems when not on shore power, unless you have a generator.

You would need to be careful with what 240v equipment you use, as the Princess 35 is fitted with just two 12v batteries of about 110ah for the domestic systems and a single 12v battery for the engine. This gives about 100ah of usable capacity, before the batteries fall below 50% SOC, which you should not do. That also assumes the batteries are in tip-top condition.

A 3kw water heater, or 3kw kettle, for instance, will draw 300a from the batteries (minus whatever the alternators are putting out), they will be down to 50% in about 15-20 mins, because the alternators cannot keep up. Do not use them. Make sure the water heater is off, the engines will heat the water. If you want to boil a kettle, get a 1kw one. This will only draw 100a from the batteries, yes, it'll take 3 times as long to boil the kettle, but drawing 100a as opposed to 300a is kinder to the batteries and the engines will likely have alternators of at least 60a, sh they'll more or less keep up with the consumption.

Lower powered equipment, such as microwaves, phone chargers etc would be fine, the alternators would run these indefinitely.

You should fit a battery monitor and keep an eye on the batteries, or you could easily kill them off. You'll soon get used to how thing affect the batteries.

 

[Sticky Fingers]

Is this Q also posted on the Princess Owners FB Group?

 

[Alex_Blackwood]

As per post #2, you need an inverter to run 240v systems when not on shore power, unless you have a generator.

You would need to be careful with what 240v equipment you use, as the Princess 35 is fitted with just two 12v batteries of about 110ah for the domestic systems and a single 12v battery for the engine. This gives about 100ah of usable capacity, before the batteries fall below 50% SOC, which you should not do. That also assumes the batteries are in tip-top condition.

A 3kw water heater, or 3kw kettle, for instance, will draw 300a from the batteries (minus whatever the alternators are putting out), they will be down to 50% in about 15-20 mins, because the alternators cannot keep up. Do not use them. Make sure the water heater is off, the engines will heat the water. If you want to boil a kettle, get a 1kw one. This will only draw 100a from the batteries, yes, it'll take 3 times as long to boil the kettle, but drawing 100a as opposed to 300a is kinder to the batteries and the engines will likely have alternators of at least 60a, sh they'll more or less keep up with the consumption.

Lower powered equipment, such as microwaves, phone chargers etc would be fine, the alternators would run these indefinitely.

You should fit a battery monitor and keep an eye on the batteries, or you could easily kill them off. You'll soon get used to how thing affect the batteries.

He may have all that. He didn't say

 

[PaulRainbow]

He may have all that. He didn't say

Bet you a fiver he hasn't

 

[Sticky Fingers]

If it’s the same owner and boat as the identical FB group post, he’s got a generator.

 

[Alex_Blackwood]

Bet you a fiver he hasn't

Think I agree but again, once again, It would be nice to know what he does have.

 

[PaulRainbow]

Think I agree but again, once again, It would be nice to know what he does have.

Yep, always good to have all the info