leisure batteries?

[djangobole]

i need to replace my leisure batteries as they are old and past it and dont last more than an evening, as i want to start to continually cruise how many should i have on board to get a reasonable time out of them, i dont run loads of equipment only lights and 12 volt fridge.

[Ex- Member]

i need to replace my leisure batteries as they are old and past it and dont last more than an evening, as i want to start to continually cruise how many should i have on board to get a reasonable time out of them, i dont run loads of equipment only lights and 12 volt fridge.

 

You'll need to do a full audit of your power consumption, from that you can work out the best size battery bank for your needs, or members can advise from that information. With solar being so cheap now, it would probably be worth considering investing in some solar power as well as batteries.

[Arthur Brown]

Find and read the Victron book, and TB training's website and the Smartgauge website. All well linked on here. At first glance you need IMO 400 - 1000amp hours of 12v lead acid cells on board, you are going to use 250Ah a day and need to budget for putting 30% more than that back into the batteries each day. So a pair of 175A alternators wouldn't be far OTT and you may need to run them for 5 hours a day either as cruising or as a generator period. You will need a back up plan (maybe a charger that can run off mains and or a generator) to give say 100A min and a fall back on that. Solar cells will be very valuable in the summer, less so in the winter.

[gary955]

At first glance you need IMO 400 - 1000amp hours of 12v lead acid cells on board, you are going to use 250Ah a day

Where did that come from!!!!!!!

[dor]

you are going to use 250Ah a day

 

Seems rather a lot for a fridge and a few lights.

 

400 AHr should be plenty. If you have a bigger bank you will really struggle to get it fully recharged which will reduce the life of your batteries significantly.

 

But as Julynian says, you need to work out exactly what your typical consumption is. A modern 12V fridge will draw about 30 AHr a day, half a dozen 20W halogen lights will draw 10 A whilst the equivalent leds will barely draw an amp.

 

Depends a lot on how much cruising you will do a day, but even with 100A+ alternators you may need to plan on charging for several hours a day or you will soon be back to where you are now; i.e. sulphated batteries with much reduced storage capacity. Remember that the amp rating of an alternator is only its maximum output; it will soon reduce significantly as for a given voltage the current is determined by the batteries.

[Robbo]

i need to replace my leisure batteries as they are old and past it and dont last more than an evening, as i want to start to continually cruise how many should i have on board to get a reasonable time out of them, i dont run loads of equipment only lights and 12 volt fridge.

 

None, leisure batteries are for leisure not liveaboard CCers...

 

Read the links posted above as well as this book.

Edited July 5, 2012 by Robbo

[gary955]

None, leisure batteries are for leisure not liveaboard CCers...

 

Read the links posted above as well as this book.

Oh for goodness sake!!!

I normally stay out of these things, but heres my advice to the OP

There are a lot of very knowlegable people on this forum when it come to electricity.....I'm not one of them, but heres my experience as a liveaboard of two and a half years.

My boat has no battery charger. It has 3 110ah batteries, one of which I replaced with the cheapest battery I could find when a cell went down. I was told on this forum that I MUST replace the whole set and invest in a hugely expensive charger and a smart something or other. I ignored that advice and six months later the single solar panel has kept the bank at more than 12.7v

I have LED lighting and a gas fridge but I do run my lappy on 12v and have a rather lovely Acoustic Energy sound system which runs every night on the inverter.

I have only run my engine about three or four times in six months to go cruising.

Everything the "experts" say can be justified on paper but walk along the canal and talk to some livaboards on some of the scruffier boats.......do they look as though they can invest in hugely expensive "essential" equiptment........does the engine in bits on the stern deck look as though it can manage 5 hours charging a day..........do the people look happy and care free?

The OP doesn't need a back up plan (unless he's in an iron lung!) he's on a ditch close to civilisation, not ocean voyaging! The worst that will happen if his batterys go flat is that he will miss an episode of Corrie. perhaps he should spend a little bit of money on a gas fridge. Not a fortune on traction batteries twin alternators and an expensive multi stage charger.

Edited July 5, 2012 by gary955

[nb Innisfree]

i need to replace my leisure batteries as they are old and past it and dont last more than an evening, as i want to start to continually cruise how many should i have on board to get a reasonable time out of them, i dont run loads of equipment only lights and 12 volt fridge.

 

 

As you can see there are already conflicting posts, for a start you do not need to charge for several hours per day, partial state of charging is an alternative and the only realistic method for off grid cruising. Don't take mine or anybody else's word for it, read the Smartgauge and Tony Brook's website and the Victron book and get genned up then you will be better able to differentiate between good and bad advice.

 

Edited to add: The average liveaboard narrowboat uses between 125 and 175 ah @12v per day.

Edited July 5, 2012 by nb Innisfree

[blodger]

If I were in your situation I would do something to prolong the life of the current batteries because that will help with the next set.

 

You can probably Ebay 2/300 watts of solar and a 30amp PMW controller and the necessary wire etc for less than the replacement cost of batts now.

 

I would be surprised, if you did that now, if you did not still have the same batts functioning satisfactorily this time next year.

[bowten]

Oh for goodness sake!!!

I normally stay out of these things, but heres my advice to the OP

There are a lot of very knowlegable people on this forum when it come to electricity.....I'm not one of them, but heres my experience as a liveaboard of two and a half years.

My boat has no battery charger. It has 3 110ah batteries, one of which I replaced with the cheapest battery I could find when a cell went down. I was told on this forum that I MUST replace the whole set and invest in a hugely expensive charger and a smart something or other. I ignored that advice and six months later the single solar panel has kept the bank at more than 12.7v

I have LED lighting and a gas fridge but I do run my lappy on 12v and have a rather lovely Acoustic Energy sound system which runs every night on the inverter.

I have only run my engine about three or four times in six months to go cruising.

Everything the "experts" say can be justified on paper but walk along the canal and talk to some livaboards on some of the scruffier boats.......do they look as though they can invest in hugely expensive "essential" equiptment........does the engine in bits on the stern deck look as though it can manage 5 hours charging a day..........do the people look happy and care free?

The OP doesn't need a back up plan (unless he's in an iron lung!) he's on a ditch close to civilisation, not ocean voyaging! The worst that will happen if his batterys go flat is that he will miss an episode of Corrie. perhaps he should spend a little bit of money on a gas fridge. Not a fortune on traction batteries twin alternators and an expensive multi stage charger.

Ooooooh,nice one have greenie.

[Gibbo]

I was told on this forum that I MUST replace the whole set and invest in a hugely expensive charger and a....

 

Show us the posts. I don't think you were ever told anything of the sort.

 

It's easy to slag a load of people off if you make something up and pretend that's what they said.

 

i need to replace my leisure batteries as they are old and past it and dont last more than an evening, as i want to start to continually cruise how many should i have on board to get a reasonable time out of them, i dont run loads of equipment only lights and 12 volt fridge.

 

The 12 volt fridge kind of is "loads of equipment". Obviously it varies from boat to boat, but on ours the 12 volt fridges used about 2/3rds of our consumption. Well it did until we switched it off.

[bottle]

Oh for goodness sake!!!

I normally stay out of these things, but heres my advice to the OP

There are a lot of very knowlegable people on this forum when it come to electricity.....I'm not one of them, but heres my experience as a liveaboard of two and a half years.

My boat has no battery charger. It has 3 110ah batteries, one of which I replaced with the cheapest battery I could find when a cell went down. I was told on this forum that I MUST replace the whole set and invest in a hugely expensive charger and a smart something or other. I ignored that advice and six months later the single solar panel has kept the bank at more than 12.7v

I have LED lighting and a gas fridge but I do run my lappy on 12v and have a rather lovely Acoustic Energy sound system which runs every night on the inverter.

I have only run my engine about three or four times in six months to go cruising.

Everything the "experts" say can be justified on paper but walk along the canal and talk to some livaboards on some of the scruffier boats.......do they look as though they can invest in hugely expensive "essential" equiptment........does the engine in bits on the stern deck look as though it can manage 5 hours charging a day..........do the people look happy and care free?

The OP doesn't need a back up plan (unless he's in an iron lung!) he's on a ditch close to civilisation, not ocean voyaging! The worst that will happen if his batterys go flat is that he will miss an episode of Corrie. perhaps he should spend a little bit of money on a gas fridge. Not a fortune on traction batteries twin alternators and an expensive multi stage charger.

 

This reminds me of the story about a bloke that fell of a twenty story building.................... as he passed each floor he was heard to say.................. So far, so good.

 

To the OP, as mentioned do a power audit, double the answer and that is the minimum battery bank required.

 

Remember though you do need to be able to replace the amount used plus fifty percent (approximately).

Edited July 5, 2012 by bottle

[nicknorman]

 

Remember though you do need to be able to replace the amount used plus fifty percent (approximately).

 

Since the bottle of truth serum is being passed round, where did this figure of "amount used + 50%" come from? In terms of current, perhaps max 10% more. In terms of power, it is a little more than that due to the difference between charging and discharging voltage. But 50%? No way unless your batts are totally knackered! Otherwise you are saying that to say take a 440AH bank from 50% to 100% you need to add an extra 110AH, which at 14v is 1.5 kwh or 1.5 kw for an hour - that is a huge amount of heat or dissociated water that simply is not produced. Urban myth.

[blodger]

Since the bottle of truth serum is being passed round, where did this figure of "amount used + 50%" come from? In terms of current, perhaps max 10% more. In terms of power, it is a little more than that due to the difference between charging and discharging voltage. But 50%? No way unless your batts are totally knackered! Otherwise you are saying that to say take a 440AH bank from 50% to 100% you need to add an extra 110AH, which at 14v is 1.5 kwh or 1.5 kw for an hour - that is a huge amount of heat or dissociated water that simply is not produced. Urban myth.

It may not be 50% but batteries are pretty inefficient at what they do and it is probably as well to stress the extra needed to get back to 100% SOC since so many short change the batts when recharging to their detriment, etc, etc

[nb Innisfree]

If bulk charging only then efficiency will be nearly 100%. If carried on to 100% soc then it may need an extra 50% pushed in but if bulk charge only is used on a daily basis (partial state of charging) with an occasional 100% absorption charge then the energy needed to replace that lost will be somewhere between 100% and 150% depending how often 100% charge is carried out.

Edited July 5, 2012 by nb Innisfree

[Richard10002]

I don't live aboard my boat, but I spend a few nights on board each week. In general, when I get on board, the batteries are fully charged showing around 12.7v+. By the time I get up next day, they usually show about 12.3v +/-. This suggests I use about 40% of a 330Ah bank in an evening and a night aboard. Fridge, TV, Speakers, Laptop, iPhone, iPad, 3MiFi. About 130Ah.

 

About 3 or 4 hours with a generator powering a 70A 3 stage charger seems to get them to the point where they are charging at about 6A, i.e. as good as full.

 

I'll soon have a 100W solar panel to maintain them while I'm not on board.

 

If I lived aboard, I'd probably like a bigger bank, so I could go longer between charges, even if I had to charge for longer when the time came.

[nb Innisfree]

I don't live aboard my boat, but I spend a few nights on board each week. In general, when I get on board, the batteries are fully charged showing around 12.7v+. By the time I get up next day, they usually show about 12.3v +/-. This suggests I use about 40% of a 330Ah bank in an evening and a night aboard. Fridge, TV, Speakers, Laptop, iPhone, iPad, 3MiFi. About 130Ah.

 

About 3 or 4 hours with a generator powering a 70A 3 stage charger seems to get them to the point where they are charging at about 6A, i.e. as good as full.

 

I'll soon have a 100W solar panel to maintain them while I'm not on board.

 

If I lived aboard, I'd probably like a bigger bank, so I could go longer between charges, even if I had to charge for longer when the time came.

 

 

40% assuming of course you still have 330ah capacity! Though I reckon 130ah isn't probably all that far out.

 

Remember, to get to a true 100% SoC takes at least 24hrs. To get to a realistic full charge 330ah needs to reduce to 0.5% of capacity which is under 2 amps.

 

A bigger bank won't take much longer to charge, it may be a little slower in bulk phase but absorption takes as long with one battery as it does with several.

[Robbo]

Oh for goodness sake!!!

I normally stay out of these things, but heres my advice to the OP

. Not a fortune on traction batteries twin alternators and an expensive multi stage charger.

 

Why dish some very good advice of basically some very good links of battery management? Just because your system on the off chance works for you it more than likely wont work for anyone else.

[gary955]

This reminds me of the story about a bloke that fell of a twenty story building.................... as he passed each floor he was heard to say.................. So far, so good.

Well OK but it's been two and a half years and I haven't hit the ground yet!

Three years is often quoted as a realistic lifespan for cheap batteries and mine were certainly not new when I bought the boat. So far my lack of battery maintenence regime has cost me less than £80 to replace the one battery that got buggered up by having the solar panel wired to its terminals rather than wired across the bank.

I cant quote you figures in ah or SOC, I dont understand absorbsion or bulk charge,neither can I tell you about battery chemistry. All I can do is tell you my experience and my experience is that I dont need a smart charger, a generator or a back up plan.

 

Gibbo. I'll try and dig out the posts that told me it would be folly not to replace the whole bank and get a sophisticated charger. I'm sure I didn't imagine it!

I didn't slag anyone off in this thread did I?

Edited July 6, 2012 by gary955

[Lady Muck]

Most boaters I know personally fall in Garys camp they have no need for a big battery bank as many dont have a fridge or a tv. Their biggest power draw tends to be a laptop.

As we moor and have hook up we got a battery charger, but when we cruise we are fine on 3 leisure batteries and 100 watt of solar. Last trip out we spent five days moored up and didnt run the engine once. Our biggest power draw is a 12v fridge. I swopped the old laptop for an ultra portable with a long battery life and an ipad. Both can be used then charged up off a panel or the engine when cruising. I also swapped the lights for LED.

Must be doing something right as our batts are 5 years old and still seem ok. We didnt replace the old bank all at once, either.

We couldn't afford to at the time, but it hasn't seemed to affect the performance as in we haven't had to chuck this lot away yet. <shrugs>

[Chris Pink]

Where did that come from!!!!!!!

 

Exactly, I typical figure for the OP would be 100Ah per day, 50 for the fridge and 50 for everything else (although this 2nd 50 has a lot of spare - TV computer type spare, pumps and lights is probably more like 15-20 Ah)

 

 

Most of the people I know in this situation will have 220 Ah of battery, or 2 'standard' leisure batteries. 3 or 4 makes for a little more time between charging but then you need to think about bigger chargers so can be self-defeating

 

 

as for batteries I am recommending US2200s at £250 for 230Ah, cheapos will probably cost £160-£180 so there's not that much in it for a battery that will stand 70% DOD routinely. Though Trojan are trying a little harder to compete at the moment I don't know whether their T105 is a better battery, it's just been traditionally more expensive.

 

.

We couldn't afford to at the time, but it hasn't seemed to affect the performance as in we haven't had to chuck this lot away yet. <shrugs>

 

Anecdotal evidence (to my mind the best kind) is beginning to suggest that solar massively extends the life of batteries, even cheap ones but especially mid-range types.

 

I would be interested to know (but have no way of finding out) whether this is because the continual charging activity prevents sulphates hardening. (as a working hypothesis)

 

 

 

...

Edited July 6, 2012 by Chris Pink

[nicknorman]

If bulk charging only then efficiency will be nearly 100%. If carried on to 100% soc then it may need an extra 50% pushed in but if bulk charge only is used on a daily basis (partial state of charging) with an occasional 100% absorption charge then the energy needed to replace that lost will be somewhere between 100% and 150% depending how often 100% charge is carried out.

50% extra for the very last few AH possibly, but to say you have to put back 50% more than you take out implies that say 220AH taken from a 440AH bank needs 330AH to recharge it. That is incorrect and very misleading.

[Chris Pink]

50% extra for the very last few AH possibly, but to say you have to put back 50% more than you take out implies that say 220AH taken from a 440AH bank needs 330AH to recharge it. That is incorrect and very misleading.

 

It's also irrelevant as, with the exception of solar, all power generators produce so much more power than a charging cycle can use.

[carlt]

When I lived aboard I never paid for batteries.

 

Blumming expensive aren't they?

[Gibbo]

How much to put back in compared to how much was taken out?

 

This is "charge efficiency".

 

The following are not guesses, they are real world measured and calculated figures.

 

From 90% to 100% SoC, charge efficiency is around 85%

 

From 70% to 90% SoC, charge efficiency is around 90%

 

From 30% to 70% SoC, charge efficiency is around 95%

 

Below 30% SoC, charge efficiency falls quite badly the lower the SoC is, and can be as low as 60%.

 

Obviously figures vary between battery types/quality etc, and also vary depending upon battery temperature and the charge current. High charge currents tend to result in lower charge efficiency, high charge voltages also lower the charge efficiency. The above figures are about average across the board.