Getting a good electrical supply

[ALAN DENMAN]

Hi, this is my first year living on a narrowboat and I'm trying to understand our electrical system better.

I'm concerned that perhaps my batteries are either not holding their charge, or they are not fully charging.  I'm running  them, often twice a day  for one hour at 1000 for 30 mins, then down to 500 revs for the last 30 mins and yet I'm only able to run the  very minimum of appliances on my 240 volt system before the my combi bleeps it's low battery warning.  Appliances I am using are a couple of mobile phones and their extra batteries plus my laptop. I have a combi inverter which I only turn on to use the 240 volt appliances.

 I also have a 12 V fridge +12 V lighting on the boat which also uses up some of the batteries of course .

Should I be running the engine for more than one hour morning and night? My domestic batteries Hannkook DC24MF. Thanks for advice. Alan

 

[Jess--]

A few things we need to know...

1. how many batteries do you have connected
2. how old are they
3. what type of fridge do you have (some types are very power hungry)

[nicknorman]

You are not charging for long enough. The problem with batteries is that it's not like filling a bucket, it's more like filling a very dense sponge. The first bit goes in easily, but it gets more and more difficult to get the charge in as charging progresses. It typically takes about 7 or more hours to properly fully charge a battery - much of the time towards the end is spent with very little current actually going in. But if you don't fully charge fairly often, the batteries become damaged (sulphated) lose capacity big-time. I would imagine that your batteries' capacity is very low now, having followed that charging regime. You will need both new batteries and a new charging regime if you want things to improve.

These days, if you are a live aboard, it makes every sense to have a lot of solar. Life without solar will be difficult and noisy. 

[dor]

With a 12V fridge and recharging a laptop you will be nowhere near charging the batteries enough.  We need the information asked for above to give a more comprehensive answer.  But basically, no, you are not charging enough.  Probably at least two hours a day at 1000rpm+ (what is the ration between your engine pulley and alternator pulley?  Probably need to run at 1500 rpm for the first hour before being able to drop the revs a bit.  THen several hours once a week.

 

crossed with Nick's!

Edited August 9, 2017 by dor

[Robbo]

35 minutes ago, ALAN DENMAN said:

Hi, this is my first year living on a narrowboat and I'm trying to understand our electrical system better.

The best thing to get would be a amp and voltmeter and learn how to read them.  These two things tell you a lot on what is happening to your batteries.    A clamp multi-meter like this https://www.maplin.co.uk/p/uni-trend-ut203-dcac-current-clamp-meter-n41nc is a good thing to have on any boat but having the gauges (digital not analogue) permanently installed is better of course.

+ Solar is always a good thing.

Edited August 9, 2017 by Robbo

[OldGoat]

As above - I have a similar power requirement and I need to charge  for around four hours just to keep the basics going and -

• I'm 24v
• 500 Ah  @ 24v = 100 Ah  batteries in normal folks' terms
• and I have a charge controller and BMS system

batteries are a lot of energy in and not a lot out.

[mrsmelly]

53 minutes ago, ALAN DENMAN said:

Hi, this is my first year living on a narrowboat and I'm trying to understand our electrical system better.

I'm concerned that perhaps my batteries are either not holding their charge, or they are not fully charging.  I'm running  them, often twice a day  for one hour at 1000 for 30 mins, then down to 500 revs for the last 30 mins and yet I'm only able to run the  very minimum of appliances on my 240 volt system before the my combi bleeps it's low battery warning.  Appliances I am using are a couple of mobile phones and their extra batteries plus my laptop. I have a combi inverter which I only turn on to use the 240 volt appliances.

 I also have a 12 V fridge +12 V lighting on the boat which also uses up some of the batteries of course .

Should I be running the engine for more than one hour morning and night? My domestic batteries Hannkook DC24MF. Thanks for advice. Alan

 

Yikes you are not charging enough and you may well now need new batteries

[Neil2]

Also, am I right in saying there's a risk of burning out the motor in the fridge compressor if you consistently try and run it off (too) low voltage? (assuming it's an older model without the low voltage cut out)    

[Alan de Enfield]

There is a 'generalisation' (and that is all it is -it may be insufficient for some users, and 'over the top' for others) of run the engine to charge the batteries for 4 hours per day and 8 hours at a weekend.

 

If you batteries have been used / left 'part-charged' then they may well be sulphated (dead) and no matter how much you charge them you are unlikely to recover their capacity.

[ditchcrawler]

I have a 240 volt fridge run via an inverter on 24/7 I also have normal pumps and LED lamps, charge the lap top and Ipad + phones. I need to run my engine between 3 and 4 hours every day to maintain a reasonable level of charge in my batteries using a Stirling Battery management unit to monitor both voltage and charge current, the charging is assisted by an Adverc regulator.  

[ALAN DENMAN]

3 hours ago, Jess-- said:

A few things we need to know...

1. how many batteries do you have connected
2. how old are they
3. what type of fridge do you have (some types are very power hungry)

4 batteries, about 1 year old and a small 12 volt fridge. 

[Alan de Enfield]

2 minutes ago, ALAN DENMAN said:

small 12 volt fridge. 

Type

Make

Model

 

[ALAN DENMAN]

3 hours ago, nicknorman said:

You are not charging for long enough. The problem with batteries is that it's not like filling a bucket, it's more like filling a very dense sponge. The first bit goes in easily, but it gets more and more difficult to get the charge in as charging progresses. It typically takes about 7 or more hours to properly fully charge a battery - much of the time towards the end is spent with very little current actually going in. But if you don't fully charge fairly often, the batteries become damaged (sulphated) lose capacity big-time. I would imagine that your batteries' capacity is very low now, having followed that charging regime. You will need both new batteries and a new charging regime if you want things to improve.

These days, if you are a live aboard, it makes every sense to have a lot of solar. Life without solar will be difficult and noisy. 

Great advice. Funnily enough, I have been looking into solar panels but wonder whether spring would be a better time to have them installed. Thanks.

[nicknorman]

35 minutes ago, ALAN DENMAN said:

4 batteries, about 1 year old and a small 12 volt fridge. 

Presumably this is a compressor fridge, not a 3-way fridge being run on 12v? A compressor fridge typically uses 25-35 Amphours in a day, maybe a bit more on a really hot day. So not trivial, but not horrendous. The thing is that pretty much regardless of the battery capacity and alternator output (within reason) it just takes a long time to get the final 10 or 20% of charge into the batteries, end of. By a long time I mean several hours. So to charge fully from the very low state where the inverter is beeping is going to take perhaps 9 hours. Or it would do if the batteries had their full capacity still.

As has been mentioned, you will need new batteries and to run the engine perhaps 4 hours a day minimum, and 8 hours one day a week. Alternatively, get plenty of solar which will fix the problem at least in the summer.

you have hit the biggest problem affecting live aboards off shore power. There is no magic fix!

[Robbo]

1 minute ago, ALAN DENMAN said:

Great advice. Funnily enough, I have been looking into solar panels but wonder whether spring would be a better time to have them installed. Thanks.

Why the delay, plenty of sun left this year.

[ALAN DENMAN]

Thanks everyone for your advice and information. I really appreciate this. 

Best wishes

Alan

[OldPeculier]

Just a suggestion, try living without a fridge for a while and see how you get on.  I used to turn mine off in the winter but realized I could, in fact, live perfectly well without it all year.   Add a little solar into the equation and you wont have to run your engine at all. 

[Richard10002]

37 minutes ago, OldPeculier said:

Just a suggestion, try living without a fridge for a while and see how you get on.  I used to turn mine off in the winter but realized I could, in fact, live perfectly well without it all year.   Add a little solar into the equation and you wont have to run your engine at all. 

How do you stop milk going off? (and other stuff that deteriorates quickly at temperatures outside a fridge?)

I can only think that you need to be moored near shops, (or passing one every day, or two), and buy fresh stuff regularly?

[Robbo]

17 minutes ago, Richard10002 said:

How do you stop milk going off? (and other stuff that deteriorates quickly at temperatures outside a fridge?)

I can only think that you need to be moored near shops, (or passing one every day, or two), and buy fresh stuff regularly?

Look inside your fridge.   What is in there that you really need and if so does it really need to be in a fridge?   I don't use a fridge at the mo but do buy milk daily  and do without butter, however you can get long life milk.  Most of the other stuff prob not really need a fridge.   The bilge is prob the coldest part of the boat, a good portion of boaters have part of the bilge showing under a kitchen cabinet so you can put food on it, unless it's a really hot day my milk can last a few days. 

Edited August 10, 2017 by Robbo

[nicknorman]

16 minutes ago, Richard10002 said:

How do you stop milk going off? (and other stuff that deteriorates quickly at temperatures outside a fridge?)

I can only think that you need to be moored near shops, (or passing one every day, or two), and buy fresh stuff regularly?

Keep a cow on the towpath? Anyway some folk consider boating not to be an endurance test, others prefer to live like cavemen and anyway don't have time to drink milk what with all the time spent whipping their naked bodies with nettles. Each to their own!

[OldPeculier]

18 minutes ago, Richard10002 said:

How do you stop milk going off? (and other stuff that deteriorates quickly at temperatures outside a fridge?)

I can only think that you need to be moored near shops, (or passing one every day, or two), and buy fresh stuff regularly?

It depends very much on your lifestyle.  I am at work every day so picking up fresh food on the way home is not a problem.  I have a cool box and putting cold milk in there keeps it fresh for 2 or 3 days.  I always keep a carton of UHT for emergencies.  If I am going off for a few days, I get my gf to freeze a couple of pints of milk at her house and bring them over.  That keeps the cool box cold for much longer.

6 minutes ago, nicknorman said:

Keep a cow on the towpath? Anyway some folk consider boating not to be an endurance test, others prefer to live like cavemen and anyway don't have time to drink milk what with all the time spent whipping their naked bodies with nettles. Each to their own!

And some folk like the peace and quiet without engines/generators running for hours every day!  As you say, each to their own!

[ditchcrawler]

1 hour ago, OldPeculier said:

It depends very much on your lifestyle.  I am at work every day so picking up fresh food on the way home is not a problem.  I have a cool box and putting cold milk in there keeps it fresh for 2 or 3 days.  I always keep a carton of UHT for emergencies.  If I am going off for a few days, I get my gf to freeze a couple of pints of milk at her house and bring them over.  That keeps the cool box cold for much longer.

And some folk like the peace and quiet without engines/generators running for hours every day!  As you say, each to their own!

How do you cool down the cool box

 

[Richard10002]

2 hours ago, Robbo said:

Look inside your fridge.   What is in there that you really need and if so does it really need to be in a fridge?

Milk, Lurpak Spreadable and Vimto ice cubes, are the regulars and are things I don't want to be without.

At a pinch I can live without ice cubes, and can tolerate soft/soggy Lurpak, but it's supposed to be fun!

For my 4 days a week on board I used to buy a litre of milk twice, but got fed up of either forgetting, or being committed to leaving the mooring and going shopping. Nowadays, I buy a 2 litre Cravendale or similar, which last the 4 days.

i tried having Long Life as a back up, but don't like the taste, (it's tolerable but I would get off my backside and find a shop, rather than drink it, other than very late at night, or early in the morning).

In winter when my previous fridge was dodgy, and running continuously, I could put milk and stuff in the cratch overnight and it would be fine... but that doesn't work in summer.

So I'm stuck with a fridge and the hassle of providing the power to run it - very much a 1st World problem

 

[Robbo]

1 minute ago, Richard10002 said:

Milk, Lurpak Spreadable and Vimto ice cubes, are the regulars and are things I don't want to be without.

At a pinch I can live without ice cubes, and can tolerate soft/soggy Lurpak, but it's supposed to be fun!

For my 4 days a week on board I used to buy a litre of milk twice, but got fed up of either forgetting, or being committed to leaving the mooring and going shopping. Nowadays, I buy a 2 litre Cravendale or similar, which last the 4 days.

i tried having Long Life as a back up, but don't like the taste, (it's tolerable but I would get off my backside and find a shop, rather than drink it, other than very late at night, or early in the morning).

In winter when my previous fridge was dodgy, and running continuously, I could put milk and stuff in the cratch overnight and it would be fine... but that doesn't work in summer.

So I'm stuck with a fridge and the hassle of providing the power to run it - very much a 1st World problem

So the question is running the engine for approx an half hour extra a day worth it for Milk and Butter?   Best to get solar !

[Neil2]

I'm perplexed why some folk seem to find it difficult to maintain enough power to run a fridge.  

All we have is a 120w solar panel and two domestic batteries.  Last year we got held up with a gearbox problem for five days but never had to run the engine, and we could still watch TV every night.  The synergetic relationship between solar and refrigeration is so blindingly obvious to me I can't understand for the life of me why so many narrowboaters don't get it.  I know it doesn't work in the winter but why do you need to run a fridge in the winter?