Batteries

[Richard X]

Hi everyone,

 

I'm about to have a widebeam Eurocruiser built by Collingwood and wanted to know anyones thought's on batteries, they're going to fit 3 x 110amp batteries and Iv'e been told to upgrade to 4 x 145amp by another boater.

 

I'm new to boating and learning all the time so Just wanted to know what anyone else thinks about batteries and amps.

 

Cheers, Richard.

[nicknorman]

It totally depends on what you expect to get out of the batteries, the intended charging method and pattern. So you'll need to tell us what power-consuming equipment you'll have, and how you will use the boat (in a marina, for holiday use, to live aboard continuous cruising etc) and how you will be charging the batteries.

 

But generally I think that for a modern boat with plenty of room, 4x110 12v batteries would be the sensible minimum, especially if you intend to have a decent sized inverter.

Edited January 22, 2017 by nicknorman

[WotEver]

What is the power audit and how will they be charged?

[Tony Brooks]

Although WotEver's post may appear rather cryptic unless you already have some knowledge about boats he is correct. The easiest thing to ruin in very short order on a boat are its batteries so unless you do the groundwork and planning first you could destroy hundreds of pounds worth of batteries.

 

You need to work out the optimum mix of: battery charging, electricity (current consumption) and battery bank size for YOUR Boat and YOUR use of it.

 

Putting in too many batteries and you will be wasting money. Putting in too few or not charging enough will ruin them in weeks of not days and constant flat batteries.

 

The power audit where you list all your electrical equipment, how much it consumes, and how long it is used for each day will guide you to the optimum bank size.

 

From that result you can work out the charging requirements and how long you need to run the particular charging method for.

 

Sample calculations can be found on my website and in several other web resources. Once you have worked through them it will give you a much more realistic idea about what is required and how things work. It may even cause you to review your electricity requirements.

[nicknorman]

This is probably an unhelpful place to mention it but really it is an energy audit, not a power audit!

[MtB]

This is probably an unhelpful place to mention it but really it is an energy audit, not a power audit!

 

 

I'm not sure either is a totally accurate term given the units we use are AH/day.

 

But then as is sometimes claimed on here, everyone knows what we mean, don't they?

[nicknorman]

I'm not sure either is a totally accurate term given the units we use are AH/day.

 

But then as is sometimes claimed on here, everyone knows what we mean, don't they?

AH isn't an energy measurement of course but it does become thus when the system voltage is known. So if we are working out the energy need per day, I'd call that an energy audit! Actually I suppose a power audit is needed as well, ie working out the peak power demand from say a 3kVA inverter. An installation that uses 30AH per day spread out over 24 hrs, will require a different battery configuration from one that uses the same 30AH whilst delivering a burst of 3kw.

[dmr]

It depends on what you want to do with the boat, how many electrical items you want to use, and even what sort of person you are.

I know a few people who live very very happily on boats with no electricity at all, and have also moored next to boats that need to run a generator 8 hours a day to meet their needs.

You probably won't really know what you need till you have spent a fair bit of time on the boat. Go for the cheapest option for now but ask the builder to leave some space to fit more or different batteries later. Note that semi-tractions (Trojans) and full tractions are a very different size and shape to common leisure batteries.

 

...............Dave

[OldGoat]

Talk of Energy Audits and the like can and are frightening to those venturing out of bricks and mortar and they go away, afraid of asking anything more.

In this case 'we' know nothing as yet, so what about some rules-of-thumb

 

Hair shirt boating (in today's terms)

Fridge

TV - small

Laptop

Lighting

services

you need 400 - 500 Ah and a separate (not uprated) 100 amp alternator/

 

Stage 2

the above plus

fridge freezer (or separate freezer) probably 240v AC

larger TV

Ebersplutter heating

you need probably the above but recharge daily

 

Stage 3 (seen increasingly on this forum)

Washing machine

Microwave

Dishwasher

Electric kettle

Tumble dryer

or any combination thereof

For which I'd go for:-

separate water cooled generator (It's a wide beam so room in the engine bay

24v battery bank - means 24v pumps, lights inverter and so on

Large inverter (for when it's not worth running the engine to boil a kettle - recent post)

Travel Power - if separate genny not considered

1000 Ah battery bank for 12v 600 Ah for 24v.

 

There will be hoots of derision on specifics - but it's the order of magnitude that I'm trying to get over.

Modern life is quite energy greedy.

 

 

 

[system 4-50]

And a key factor is how much use you are going to make of gas (LPG).

[dmr]

Talk of Energy Audits and the like can and are frightening to those venturing out of bricks and mortar and they go away, afraid of asking anything more.

In this case 'we' know nothing as yet, so what about some rules-of-thumb

 

Hair shirt boating (in today's terms)

Fridge

TV - small

Laptop

Lighting

services

you need 400 - 500 Ah and a separate (not uprated) 100 amp alternator/

 

Stage 2

the above plus

fridge freezer (or separate freezer) probably 240v AC

larger TV

Ebersplutter heating

you need probably the above but recharge daily

 

Stage 3 (seen increasingly on this forum)

Washing machine

Microwave

Dishwasher

Electric kettle

Tumble dryer

or any combination thereof

For which I'd go for:-

separate water cooled generator (It's a wide beam so room in the engine bay

24v battery bank - means 24v pumps, lights inverter and so on

Large inverter (for when it's not worth running the engine to boil a kettle - recent post)

Travel Power - if separate genny not considered

1000 Ah battery bank for 12v 600 Ah for 24v.

 

There will be hoots of derision on specifics - but it's the order of magnitude that I'm trying to get over.

Modern life is quite energy greedy.

 

 

 

 

Oh dear me, I always thought we were posh luxury boaters but I now realise we are just hair shirters with a washing machine instead of the small TV.

 

Could be worse though, I guess quite a few boats don't even make the hair shirt category.

 

Good post!

 

...............Dave

[cuthound]

Just wondering, does your washing machine get the hair shirt clean enough?

[MtB]

Dave's observation that you won't really know your energy requirements until you have a few months of boating under your belts makes a lot of sense.

 

On the other hand listing the electrical equipment you've ordered or plan to fit will give everyone here a good basis for estimating your likely electricity use. Can you list everything you're having fitted that will run on electricity please? Everything, not just the major things!

 

It will be helpful if you can outline how you plan to charge your batteries too i.e. make and model of alternator (or engine) you're having fitted, and any auxiliary generator you're considering. And what solar installation you're having, if any.

 

Also we'll need to know if you are living aboard or it's a hobby boat, and whether you'll have a mooring with a mains electricity supply.

Edited January 23, 2017 by Mike the Boilerman

[Gareth E]

What's the consensus: having done the power audit; how many days of use should a battery bank be?

[dmr]

What's the consensus: having done the power audit; how many days of use should a battery bank be?

 

Again this depends very much upon how the boat is to be used and the desires of the owner.

At one extreme is a marina (landline) based boat that cruises every day when out, this needs very little battery capacity.

The other end is a boat that will be out in winter and would like to moor up for the maximum 14 days with an owner who prefers minimal engine/generator running.

 

............Dave

[WotEver]

What's the consensus: having done the power audit; how many days of use should a battery bank be?

Absolute minimum: 2.5 - 3 x daily usage.

 

How much bigger than that entirely depends on your charging regime. If you go for a few days prior to a decent charge then obviously you need to go much bigger but you'll need to be using traction or semi-traction to enable you to equalise them hard and regularly

This is probably an unhelpful place to mention it but really it is an energy audit, not a power audit!

Not if you calculate it in Wh/day...

[Dave_P]

To the OP, if I was in your shoes I'd look at it one of two ways.

 

1. Put a basic set of 3x100ah batteries in and see how it goes, but allow space for adding more batteries. You won't know how your boat usage will pan out. I use my boat quite differently to how I did a few years back. You will also risk less if you screw up your batteries due to inexperience (as many do).

 

2. The cost of batteries is relatively small compared to the cost of a new boat so stick in as many as you can afford. For around £1000 you could have an amazing battery bank.

 

I'd go for option one.

[Richard X]

Hi, I will be having:

 

12v Fridge and Freezer

55" TV

Kettle just in case I get visitors (I don't drink tea or coffee)

Standard single Neff oven

Washing machine

Tumble dryer (or Washer Dryer)

Microwave (maybe but I don't really use one)

Tumble dryer

LED lighting

Computer

And charging my phone up

I think that's it!

I will be on hook up but may decide to be a continuous cruiser or decide I can no longer afford the mooring fees

Oh and I will be live aboard

To the OP, if I was in your shoes I'd look at it one of two ways.

 

1. Put a basic set of 3x100ah batteries in and see how it goes, but allow space for adding more batteries. You won't know how your boat usage will pan out. I use my boat quite differently to how I did a few years back. You will also risk less if you screw up your batteries due to inexperience (as many do).

 

2. The cost of batteries is relatively small compared to the cost of a new boat so stick in as many as you can afford. For around £1000 you could have an amazing battery bank.

 

I'd go for option one.

Thanks Dave that's useful, I may just go with what they're putting in and let them know I may add another so leave some room?

 

Thanks everyone!

Dave's observation that you won't really know your energy requirements until you have a few months of boating under your belts makes a lot of sense.

 

On the other hand listing the electrical equipment you've ordered or plan to fit will give everyone here a good basis for estimating your likely electricity use. Can you list everything you're having fitted that will run on electricity please? Everything, not just the major things!

 

It will be helpful if you can outline how you plan to charge your batteries too i.e. make and model of alternator (or engine) you're having fitted, and any auxiliary generator you're considering. And what solar installation you're having, if any.

 

Also we'll need to know if you are living aboard or it's a hobby boat, and whether you'll have a mooring with a mains electricity supply.

Not sure what alternator but I'm having a Beta 75 engine

4 or 6 Solar panels will be fitted when I can afford but that might be 2 years away

I'd like a generator but again that might be 5 years away as my budget won't stretch that far.

[mross]

Yes, tell the builder to fit three but install a battery box that has room for one or two extras in case you fit more later.

[Richard X]

So 110amp or 145amp like I've been advised

 

Yes, tell the builder to fit three but install a battery box that has room for one or two extras in case you fit more later.

Ok great, I think that's what I'll do.

 

So 110amp or 145amp like I've been advised?

[ditchcrawler]

Hi, I will be having:

 

12v Fridge and Freezer

55" TV

Kettle just in case I get visitors (I don't drink tea or coffee)

Standard single Neff oven

Washing machine

Tumble dryer (or Washer Dryer)

Microwave (maybe but I don't really use one)

Tumble dryer

LED lighting

Computer

And charging my phone up

I think that's it!

I will be on hook up but may decide to be a continuous cruiser or decide I can no longer afford the mooring fees

Oh and I will be live aboard

Thanks Dave that's useful, I may just go with what they're putting in and let them know I may add another so leave some room?

 

Thanks everyone!

Not sure what alternator but I'm having a Beta 75 engine

4 or 6 Solar panels will be fitted when I can afford but that might be 2 years away

I'd like a generator but again that might be 5 years away as my budget won't stretch that far.

I don't think you will run a cooked and a washer dryer on 3 batteries

[mross]

See what they offer pricewise for three of each size. Perhaps they only use one make.

 

let us know what he suggests - make, model and price and we will find summat better!

Edited January 23, 2017 by mross

[Richard X]

Dave's observation that you won't really know your energy requirements until you have a few months of boating under your belts makes a lot of sense.

 

On the other hand listing the electrical equipment you've ordered or plan to fit will give everyone here a good basis for estimating your likely electricity use. Can you list everything you're having fitted that will run on electricity please? Everything, not just the major things!

 

It will be helpful if you can outline how you plan to charge your batteries too i.e. make and model of alternator (or engine) you're having fitted, and any auxiliary generator you're considering. And what solar installation you're having, if any.

 

Also we'll need to know if you are living aboard or it's a hobby boat, and whether you'll have a mooring with a mains electricity supply.

Hi, It's having a 80amp dedicated alternator, is this big enough?

And a key factor is how much use you are going to make of gas (LPG).

I'm just using the gas for the hob.

[mross]

You are not fitting an electric oven, surely????

[Richard X]

You are not fitting an electric oven, surely????

Yes I'm having a Neff single oven.