8 x 200ah batteries die after 18 months

[MedMilo]

In April last year I took delivery of a new Fairline Sq65 which I'd specified to have 8 x 200ah Mastervolt gel domestic batteries hooked up to a Mastervolt 2kw inverter. We spend a good deal of time at anchor and want to be able to charge phones, watch tv, boil kettle, run dishwasher without always needing to run the genny. I understand that applications which generate heat (kettle/dishwasher) use lots of power however with a total of 1600ah of capacity I would have thought the occasional kettle boil would be fine - it certainly was when I had the same set-up on my Sq 58.

Over the 18 months since new, all 8 batteries have 'cooked' and have needed replacing (at €650 each!), thankfully under warranty. The dealer (BUK) have been incredibly supportive thus far but are saying that their battery experts think that inverters are nothing but trouble and will knacker batteries within one or two years. I find this hard to believe and this was certainly not the case with my last boat - as I understand it most 60 ft + sailing boats would be fitted with an inverter of this sort of size hooked up to a large battery bank.

I just want to know whether this set up should work but I somehow got a faulty batch of batteries / faulty installation or whether the general view is that a biggish inverter being used to run 1-2000w appliances from time to time is bound to kill even a battery bank of this size. In which case I guess I'll have to seriously consider BUK's suggestion of a small (5kw) 'sacrificial' generator instead of the batteries. But that'll somewhat spoil the atmosphere in the quiet Med anchorages we enjoy!

 

[rafiki_]

I had a 2kw inverter on my previous boat, and this died before the batteries. Lead acid by the way. As long as you don't drain the batts too far down, I don't believe the inverter should be a problem.

 

[Barbican]

+1 - would have thought it was the charging regime for the banks.

 

[Lon nan Gruagach]

One very important thing is the cables attached to the batteries. If these are not identical (length) then one battery will be doing more than its fair share, it will die early. Followed by the next in line and you will end up with a cascade failure that will wipe out your bank.

A typical (bad) installation will be:
wire from switch panel to battery 1
loop from battery 1 to battery 2
loop from 2 to 3 etc

better is if the +ve starts at one end and the -ve starts at the other.

ideal is each battery connected to +ve and -ve point or bus bar

 

[Boat2016]

I would contact Mastervolt, it's their products and they should be able to give you the answer you need.

 

[Billy Blue]

One very important thing is the cables attached to the batteries. If these are not identical (length) then one battery will be doing more than its fair share, it will die early. Followed by the next in line and you will end up with a cascade failure that will wipe out your bank.

A typical (bad) installation will be:
wire from switch panel to battery 1
loop from battery 1 to battery 2
loop from 2 to 3 etc

better is if the +ve starts at one end and the -ve starts at the other.

ideal is each battery connected to +ve and -ve point or bus bar

Just to clarify and make sure I understand, do you mean the negative from the inverter should be connected to one end of the battery bank (negative obviously) and the positive from the inverter to the other end (positive) of the battery bank?
Thanks

 

[BartW]

killer for any battery is discharge them too low ( < 50% )
occasionally using them for a kettle, or hair dryer, or anything thats heating, is disaster for battery's,

if you have 8 x 200Ah battery's to get 24V, you have 800ah available (not 1600ah)
but still this is a lot, BUT you would be surprised how quickly the battery's are below their operational charge range (fe when using a kettle)
we have 12 x 105Ah @ 24V, so 630Ah avialable, on a 70ft boat, and we use invertors intensively, (2 x 5KW)
but the only way to do that without "cooking" the battery's is:
install a Battery monitor that gives alarm when the charge is blelow xx % (we set this at 60%), and or make a automatice start system of the genny,
also we have installed the system in such a way that heavy consumers, are never fead directly from the invertor in case there is no genny nor shore power,
(airco, boiler, dishwasher, oven)

the battery monitor does more than just watching the voltage on the battery terminals,
the main thing it does, is measure via a big shunt resistor, the amps that go in and out the battery bank, and from that calculate their charge status,
the unit we use is from Victron, BMV 700, (cost approx 150 euro including the shunt), but I guess Mastervolt has something similar,

some invetors give alarm or switch off when the battery voltage is below a certain value, this NOT a good indicator for the charge status,
when the battery's are discharged at -50%, the voltage should still read 12,3V / 24,6V which is perfectly in their operational voltage range,
if the voltage on the battery's comes below 12V, you have started to severely damage the battery's !!!

imo it doesn't make sense to use expensive gel battery's
we don't use expensive victron battery's (my business is Victron dealer)
we use deep cycle 105Ah lead battery's ( at approx 85 euro per piece at Barden UK)
AFAIK it is a US/OEM make, rebranded by Varta

 

[Lon nan Gruagach]

Just to clarify and make sure I understand, do you mean the negative from the inverter should be connected to one end of the battery bank (negative obviously) and the positive from the inverter to the other end (positive) of the battery bank?
Thanks

Yes. If you calculate the total cable length from switch panel to each battery in this configuration, they all come out the same. This set up is much much better than both connected at one end of the chain, but I have a feeling (the maths is quite horrendous) that a + and - terminal post near the bank with identical cables to each battery is the ultimate configuration.

see here http://www.smartgauge.co.uk/batt_con.html for a very well written explanation. (Seems I was right about the better solution)

 

[BartW]

this is the best way to connect battery's on a boat,
drawing is courtesy to MapisM

picture is taken from this thread,
where poster Annageek gives loads of very good info on Battery's, and their connection

http://www.ybw.com/forums/showthread.php?414861-Battery-consumption-of-a-fridge

 

[jrudge]

As a fellow S65 owner ( until 9 days ago!) we had all our domestic batteries fail within warranty. As did another S65 - the one before ours.

HOWEVER ... these were the batteries supplied by Fairline and were unbranded and from what i gather cheap.

You say you have Mastervolt batteries so if this is indeed the case our failure is not relevant to your case.

someone suggested contacting Mastervolt which is probably best, and i assume they are the ones warranting the batteries in any event ( i hope for for Nick's sake!).

My own view driven only by experience and nothing at all technical is that an inverter hammers the batteries, and the drains you are looking at like dishwashing etc would make a huge drain on the bank. As bart says you only really have circa 800 ah, which if my maths with the voltages is correct would give you a total of 80 amps at 240v for an hour - assuming 100% efficiency and a perfect to spec battery bank. Real world this is probably more like 60 amps for an hour. The base level of current i see on the S65 ignoring AC when on shore power is about 20 amps - so if could go over 3 or so hours. Remember also that this bank will be running the other 24v domestics as well and the standard bank of 4 house batteries lasts about 12 hours by the time it has run lights, refrigeration etc which will reduct the capacity further depending on when the 240v us used ( boiling kettles and the toaster after a night at anchor is pulling from depleted batteries.)

You have had this working before i know on your last boat, so the contact Mastevolt if it is their inverters and batteries is probably the best bet. The suggestion to auto start get at 60% also seems a good idea.

 

[MedMilo]

Thanks Bart, that's v helpful, as was your earlier post. I know very little about battery installations but have been able to easily disconnect battery pairs throughout the summer as they've failed and the remaining baterries have worked fine. So it seems they've weren't wired up this way!

 

[MedMilo]

One very important thing is the cables attached to the batteries. If these are not identical (length) then one battery will be doing more than its fair share, it will die early. Followed by the next in line and you will end up with a cascade failure that will wipe out your bank.

A typical (bad) installation will be:
wire from switch panel to battery 1
loop from battery 1 to battery 2
loop from 2 to 3 etc

better is if the +ve starts at one end and the -ve starts at the other.

ideal is each battery connected to +ve and -ve point or bus bar

Okay understood, have passed this on to the guys looking this. Many thanks.

 

[MedMilo]

As a fellow S65 owner ( until 9 days ago!) we had all our domestic batteries fail within warranty. As did another S65 - the one before ours.

HOWEVER ... these were the batteries supplied by Fairline and were unbranded and from what i gather cheap.

You say you have Mastervolt batteries so if this is indeed the case our failure is not relevant to your case.

someone suggested contacting Mastervolt which is probably best, and i assume they are the ones warranting the batteries in any event ( i hope for for Nick's sake!).

My own view driven only by experience and nothing at all technical is that an inverter hammers the batteries, and the drains you are looking at like dishwashing etc would make a huge drain on the bank. As bart says you only really have circa 800 ah, which if my maths with the voltages is correct would give you a total of 80 amps at 240v for an hour - assuming 100% efficiency and a perfect to spec battery bank. Real world this is probably more like 60 amps for an hour. The base level of current i see on the S65 ignoring AC when on shore power is about 20 amps - so if could go over 3 or so hours. Remember also that this bank will be running the other 24v domestics as well and the standard bank of 4 house batteries lasts about 12 hours by the time it has run lights, refrigeration etc which will reduct the capacity further depending on when the 240v us used ( boiling kettles and the toaster after a night at anchor is pulling from depleted batteries.)

You have had this working before i know on your last boat, so the contact Mastevolt if it is their inverters and batteries is probably the best bet. The suggestion to auto start get at 60% also seems a good idea.

Hi J - sorry to hear you've sold Sohnar, lovely boat, hope you'll be back afloat soon! This is very interesting and the 'latent' consumption you describe, added to the spikes for appliances, leads me to think that perhaps carrying all those heavy batteries around isn't really such a good idea after all. I just hate the idea of a 23kw genny running just to occasionally boil a kettle or charge phones, so perhaps the small 5kw Onan is worth exploring - it seems to only weigh the equivalent of just over two batteries and could just be replaced when knackered I guess. And then just have four 200ah lead acids as comes OEM from Fairline. Food for thought...

 

[Portofino]

I guess it all depends how you use the boat -in the Med .
We have a much smaller tub with a tiny Mase 3.5 kw Geny .
There's an inverter too ,from my rough Italian translation in the hand book it's for hot water heating ,to get 220 V into the hot tank ,when motoring .There is no circuit from an engine ,only a 220 V element .
We have only 4 x180 ah ,two service ,two engines ,and it's all 24 V the DC .
So how do we cope when cruising ,anchoring off ,tied to bouy , on a visiting overspill berth with zilch shore power in high summer ?

Well we have various guages ,so can see discharge rate ,how many Ah are needed to top up ,or turned or round left .
We have V guages -go up to way past 24 , usually 27-28 V so I can see the state .
At anchor after typically 6-8 hrs on te domestic say from 11 am to 5-6 ish m ,we "Geny up "
The hob is ceramic so we need 220 v for cooking ,
In the Summer boilling the kettle is not really needed at pm ,more like an iced pastis or rose .
We Allways go through loads of ice ,two fridges and they seem thus far to be able to keep up with the ice demand .
While the Geny is on kids /adults can charge devices and of course the Dolphin all singing and dancincing ( fitted last year) 80ah charger is turned on - only takes a short time less than 1-2 hours to top up .
Turn it -geny off early evening .
Turn it on in the Am for breakfast - yup kettle ,but no hob , and top up devices etc .
Some times for 1/2 h at lunch we may "Geny up "too -not for bat topping up more for cooking .
Noise - sure ,but noise only ,it's well installed ,no vibrations / resonations .
I have added some ,an extra layer of lead sheet sound proofing inside the allready sound proof box .
The E room is well insulated too .
On the bow or sat on the B platform you can not hear it .
In the cockpit -sure ,but you could have some music on ?
Or factor boat usage -eg at 4-5 pm need to go ashore to forage ( ran out of beer ) or go paddle boarding etc ,then turn it on to top up .

So for us we just use it -via charger - Geny and weave it into the day .

 

[Hurricane]

Right
I've been having similar problems.
This is a very topical subject for me - I'm currently working on finding a solution.
And I was going to start a thread on this very problem.

This year I bought some really VERY cheap deep cycle leisure batteries and they haven't lasted.
However, I believe that they have shown me where my problem is.

Here's a question for you.
Are you putting back (recharging) the full amount that you have taken out.
I suspect not - in order to do that, you would have to run your generator for most of the day.

I'm not sure that jrudge's maths are correct.
To make a statement of "I have 800ah", you need to specify the voltage of the battery bank.
Most of our size of boats use 24v so if you are simply adding the ah rate of all your batteries, you are over estimating the bank size.
For example, my battery bank is 6 No 12v (125ah) batteries.
They are wired in 3 banks of 2 batteries.
That gives me 375ah at 24v but we know that we can only use 50% of that value - so in reality, I only have 187ah available.
And this is my point - THAT ISN'T VERY MUCH

Now lets look at my usage
I have one of the Victron battery monitors that Bart has recommended.
Typically, when we are running on the batteries, the ship systems are drawing about 15a (at 24v).
Fridges amount to about 9a or 10a of that total.
I know this is fact - I checked the value only this morning just before I left the boat.
So, if we consider a typical overnight at anchor, my boat will consume about 15a x 10 hours (150 amp hours).
Note that this only leaves 37ah left.
OK - so I run the generator first thing in the morning for a couple of hours.
I have a 100a Mastervolt battery charger which (at best) only charges the batteries at 80a.
As the batteries start to charge, the charge rate falls - typically after an hour, they are only taking 32a.
So, there is no way that a couple of hours recharging with the generator will replace the power that has been used overnight.
To fully charge the battery bank, you need to run the charger for many hours.
It has taken me several seasons to understand this.

Most boats spend most of their time "plugged in" to shore supply where the battery chargers are running all the time.
But we don't run our generators to just "top up" the batteries when the battery chargers are only going to add a few amps.

The net result is that over about a week at anchor, the amount of power in the battery bank gradually decreases until one night it gets to a dangerous (for the batteries) voltage and we end up knackering the batteries.
If all you do is pop out from your marina for a couple of nights, you probably wouldn't see the problem.

So, to recap and put is simply.
I'm not putting back what I am taking out.

I can't see a good solution but I am considering the following.

1 - A Bigger Battery Bank
I don't have space for any extra lead acids
Switching to Lithiums would give extra capacity.
However a bigger bank just "puts off the inevitable"

2 - Additional Battery Charger(s)
I spoke to a very helpful guy at Aquafax who said that they have a formula for the max size of battery charger.
He didn't think that a faster charger (or multiple chargers) would make enough difference - remember most current is being delivered at the beginning of the charge cycle and there is a limit that lead acid batteries will charge at.
I was going to do a test this week - I have an extra (spare) battery charger in my shed but I forgot to take the interconnecting cables with me on this trip so I couldn't do any tests.
Gut feeling is that bigger or an extra battery charger won't help.

3 - Run the Generator for Longer.
This is the cheap option but I think it would need a good 6 to 8 hours running at very little load to replace the overnight battery usage.

4 - Solar Panels
I think I could fit about 600watts of solar panels to our eyebrow.
By "eyebrow", I mean the part of the flybridge over the lower helm and in front of the flybridge helm.
YUK - I hear you all say.
But I'm considering temporary panels that could be quickly fitted just before setting off on a long cruise where I expect to anchor a lot.
Essentially, there seem to be three types of solar panels - Domestic (framed) panels - Flexible Panels - and Semi Flexible Panels.
Semi flexible seem to be the best for this application but I'm still researching.
Using the correct type of controller, I think that I could get a peak charging current of 25a (at 24v).
On a good sunny day, that could (after a couple of hours with the generator in the morning as usual) "put back" what we have used.

Still lots to consider on this subject but I'm now beginning to see where my problem lies.
And I think this is the problem the the OP has experienced.

 

[petem]

Mike, if your fridges are consuming a third of your power, are they the most efficient you can buy? And have you gone all LED for lighting?

 

[Portofino]

We have not got trad and cheaper lead /acid bats , ours are something else ? not sure .
But actually do top up in 1-2 hrs ,I've seen up to 40 ah go in at first rapidly dropping to 5 ish then zero by the time we are ready to turn the Geny off .Just to be sure we are talking domestic bats here.
Our fridges turn off below a certain V ,so no risk of a night time bat knacker scenario .
We have not got LEDs just normal 24 V bulbs , but theres at least two lighting options in each space ,ones s a low usage
Eg in the man salon we have a single light ,throw back to yachties Nav light that is over the saloon table .
How ever the bogs are electric and most cuboards /lockers have internal 5W cantalupi illuminating when open .
We only spent 3 days / nights with out shore power / motoring sitting out a storm ,and genying up a few hrs a day topped up .
Can,t see us stuck for a week with out engines running ,
I was a bit sceptical when I bought it 3.5 Kv Geny ? --- not up to the job etc ,but a reccomended boat sparkie -who Sunseeker use for call outs ( charter boat skippers / guests can be demanding ) - while installing my new Air Con - noticed the original 40ah charger was only pushing out -measured it - -4 amps .
This manifested in a fridge "fault " cos the V kept dropping /ie more out then going in .
So I would before shelling out any €€ ,check out your "more out then in " threoy .
Cos you charger should not take "all day " --- I wonder if it's working properly - thing is he told me they don,t just pack in they decay ,interns of output -stuff like v sensitive fridges suffer 1st .
It's such a big prob charger decay ,that he keeps then them on the Van , I ended up with a 80 ah ( OEM was 40 ) for a SS yacht 75 .

 

[John100156]

PV would make a lot of sense in this application Mike - as you know fridges will only draw maximum running current for short duration depending on the number of times you open the door, which I expect on JW is very frequent...!

 

[jfm]

Milo, sorry to hear of your troubles. I agree much of the above and BartW is of course correct that you have 800ah@24v not 1600. I think a big part of your problem, in addition to the above, is not enough charge. When that gel battery bank is depleted to say 60% it will accept 360amps of charge yet you have I think just 1x100amp charger. With such a small charger you'd need to run the genset and charger nearly all day to get the batteries up to say 95%+, which rather defeats the purpose of the whole exercise. When you charge I bet you are repeatedly charging to 75% or 80% or something. Repeated discharge to 50% followed by repeated charge to only 75 is VERY bad for the batteries.

I have half your Ah and double your battery charging, and when my half sized battery bank is down to 50% it will accept 175 amps of charge for the first 3/4 hour or so. Thus, with say 2.5 hour of genset I can get them close to 100% recharged (charge acceptance isn't linear; it reduces with a sort of half life, so it is best to aim for 95% rather than 100).

Without a proper battery monitor that computes the % of discharge you are flying blind anyway, but with 100Amps of charge and 800Ah of capacity you can be confident, even if flying blind, that you're flying too low.

So I think you should install say 2 extra 100amp chargers in parallel, to get 300Amps of charge. Of course this needs skilful and somewhat complex installation work because that's quite heavy duty stuff and it wont be easy to find engine room space (I have stacked the chargers rather than placed them side by side, on previous boats).

I've said to you before I think that I just don't buy this "loads of batteries" thing. I flick the genset on to use the dishwasher or whatever, and with about 180 Amps of charge that nicely puts a lot of charge into the batteries for the 32 minute dishwasher cycle. As you add more batteries without adding a proportionate amount of charge capacity (that being 100amps of charger per 200Ah of battery, very roughly) you just end up destroying them by not recharging them enough, unless you run the genset lots, which is the polar opposite of what you're trying to do. A battery has charge acceptance limits that are enough of a PITA on their own without you adding to the problem by not even giving them enough charge rate to hit that limit.

And for sure never do the false economy of using ordinary lead acid batteries - their charge acceptance is much much smaller than gel or agm. Because of the understandable desire to get the genset turned off asap you will never get a decent percentage of charge into them. You must get AGM or gel.

I don't think a small genset is a solution to your problem at all.

 

[Asm]

PV would make a lot of sense in this application Mike - as you know fridges will only draw maximum running current for short duration depending on the number of times you open the door, which I expect on JW is very frequent...!

Good point John, I've known Mike just leave the door open, no wonder the battery goes flat!
Note to forum - this is an 'in' jest - sorry