What should I have done to get better service from my new batteries?

[Theo]

Back in May I bought a new set of batteries. Seven domestics totalling 770Ah nominal at the 100hr(! I didn't get that info when I bought them and didn't ask. This was a mistake.) rate.

 

Over the past couple of months they have been losing capacit to the extent that I am having to run then engine every day. I had hoped to avoid this by lashing out on a really big bank. The question is: have I bought duff batteries or have I worn then out by misuse?

 

Battery type: Leoch SFL-110 (Adventurer SFL)

The data sheet that was emailed to me says that the MCA is 750. I don't know what MCA means.

 

I don't have an Ah meter but by not using any 12V equipent for a bit and measuring what has passed thorugh the inverter using a plug in kWh meter and comparing these readings with my SmartGauge it seems to me that the actual capacity has dropped to about 1/6th of the nominal.

 

I believe that I have treated them well.

 

1. The usual minimum SOC has been 50%. The absolute minimum has been 42% and that on only one occasion. More frequently (about once a month) I have allowed them to go to 48%.

 

2. By having so many batteries the charging rate has been very low which should have been kinder. I would say that at the satr of charging the current per battery has never exceeded 1A.

 

3. And the discharging rate has also been very low which will have allowed Mr Peukert to do his stuff.

 

4. I have set the maximum voltage on the alternator (machine sensed) at 14.6V

 

5. We continuously cruise so they have mostly had daily use. If we leave the boat for a visit the solar panels charge the bank thriugh the MPPT controller and hold them close to 100% SOC.

 

Since I fitted the ammeter in the alternator output I have realised that the tail off in charging current seems to start very early. By the time the SOC has reached 65% the current per battery has dropped to about 2A with the charging voltage at 14.3V.

 

Is the problem that I have bought rubbish batteries or something in the way that I am using them.

 

Hoping for enlightenment.

 

Nick

 

[rogeriko]

You have to find out the number of times you can go to 50% DOD (depth of discharge) many leisure batteries are only 120 times. Whereas forklift cells are about 2000 times. This figure will give you the life expectancy of your batteries. Rolls batteries are also around 1600/2000 times 50% DOD.

 

Looking at their website they say their AGM batteries are good for 400 cycles and they also say that their AGM batteries will last 4 times longer than the normal batteries which to me means your batteries are only good for 100 cycles or just over 3 months. For that sort of daily use you need Rolls or Trojan batteries as used in most off-grid houses where deep daily discharges are the norm. I have posted before about this.

 

http://www.canalworld.net/forums/index.php?showtopic=72805&hl=%2Brolls+%2Bbatteries#entry1476629

Edited January 21, 2015 by rogeriko

[Tonka]

MCA is Marine Cranking Amps. It is like CCA (Cold Cranking Amps) but measured at a different tempurature

[bizzard]

Back in May I bought a new set of batteries. Seven domestics totalling 770Ah nominal at the 100hr(! I didn't get that info when I bought them and didn't ask. This was a mistake.) rate.

 

Over the past couple of months they have been losing capacit to the extent that I am having to run then engine every day. I had hoped to avoid this by lashing out on a really big bank. The question is: have I bought duff batteries or have I worn then out by misuse?

 

Battery type: Leoch SFL-110 (Adventurer SFL)

The data sheet that was emailed to me says that the MCA is 750. I don't know what MCA means.

 

I don't have an Ah meter but by not using any 12V equipent for a bit and measuring what has passed thorugh the inverter using a plug in kWh meter and comparing these readings with my SmartGauge it seems to me that the actual capacity has dropped to about 1/6th of the nominal.

 

I believe that I have treated them well.

 

1. The usual minimum SOC has been 50%. The absolute minimum has been 42% and that on only one occasion. More frequently (about once a month) I have allowed them to go to 48%.

 

2. By having so many batteries the charging rate has been very low which should have been kinder. I would say that at the satr of charging the current per battery has never exceeded 1A.

 

3. And the discharging rate has also been very low which will have allowed Mr Peukert to do his stuff.

 

4. I have set the maximum voltage on the alternator (machine sensed) at 14.6V

 

5. We continuously cruise so they have mostly had daily use. If we leave the boat for a visit the solar panels charge the bank thriugh the MPPT controller and hold them close to 100% SOC.

 

Since I fitted the ammeter in the alternator output I have realised that the tail off in charging current seems to start very early. By the time the SOC has reached 65% the current per battery has dropped to about 2A with the charging voltage at 14.3V.

 

Is the problem that I have bought rubbish batteries or something in the way that I am using them.

 

Hoping for enlightenment.

 

Nick

 

My opinion is to have the least amount of batteries as possible, easier to keep em charged. If I need for long periods not to run the engine I might say have 3 or 4 extra ones all connected out with isolater switches so as to connect them in as needed. and then a long long cruise to charge em all up again.

[Theo]

You have to find out the number of times you can go to 50% DOD (depth of discharge) many leisure batteries are only 120 times. Whereas forklift cells are about 2000 times. This figure will give you the life expectancy of your batteries. Rolls batteries are also around 1600/2000 times 50% DOD.

Ok but where do you find this info?

N

My opinion is to have the least amount of batteries as possible, easier to keep em charged. If I need for long periods not to run the engine I might say have 3 or 4 extra ones all connected out with isolater switches so as to connect them in as needed. and then a long long cruise to charge em all up again.

I don't see why this makes them easier to keep charged. I would have thought that the amount of charging that is needed depends on the amount of discharging that they have been given. This will be the same in Ah however many batteries you have.

 

N

[rogeriko]

I edited my post while you were typing to add

Looking at their website they say their AGM batteries are good for 400 cycles and they also say that their AGM batteries will last 4 times longer than the normal batteries which to me means your batteries are only good for 100 cycles or just over 3 months. For that sort of daily use you need Rolls or Trojan batteries as used in most off-grid houses where deep daily discharges are the norm. I have posted before about this.

[bizzard]

Ok but where do you find this info?

N

I don't see why this makes them easier to keep charged. I would have thought that the amount of charging that is needed depends on the amount of discharging that they have been given. This will be the same in Ah however many batteries you have.

 

N

I don't know what your usage is Nick. But 7 sounds an awful lot to keep charged if your not on a landline.

There used to be a chap here with a wide beam who went off to cruise about, he was power crazy and had every electrical gizmo under the sun. Whilst he was here he got on everyones nerves by keep tripping the mains out. He kept adding batteries, cooking batteries, replacing them, ended up with 9, bigger and bigger alternators fitted, a 3000w generator, then a mains voltage travel power fitted and then 1000w of solar power and still couldn't cope. He was also forced to cruise virtually 24/7 trying to keep em charged. He's ended up permanently in another marina somewhere tripping all them out now I expect.

Edited January 21, 2015 by bizzard

[smileypete]

Quite a few past topics on sealed leisures underperforming...

 

Some very careful EQ charging (with full precautions and responsibility taken) could well breathe some life back into them.

 

cheers, Pete.

~smpt~

Edited January 21, 2015 by smileypete

[Theo]

I don't know what your usage is Nick. But 7 sounds an awful lot to keep charged if your not on a landline.

There used to be a chap here with a wide beam who went off to cruise about, he was power crazy and had every electrical gizmo under the sun. Whilst he was here he got on everyones nerves by keep tripping the mains out. He kept adding batteries, cooking batteries, replacing them, ended up with 9, bigger and bigger alternators fitted, a 3000w generator, then a mains voltage travel power fitted and then 1000w of solar power and still couldn't cope. He was also forced to cruise virtually 24/7 trying to keep em charged. He's ended up permanently in another marina somewhere tripping all them out now I expect.

My point remains.

 

The number of Ah you need to generate depends not on how many batteries you have only on how many Ah you use between charges. If I have 2 batteries and they discharge to 50% then 4 batteries would discharge to 75% and 8 to 87.5%. (Assuming that is, you started at 100%)

 

N

Quite a few past topics on sealed leisures underperforming...

 

Some very careful EQ charging (with full precautions and responsibility taken) could well breathe some life back into them.

 

cheers, Pete.

~smpt~

Ah! Equalisation. That is what I cannot do easily with my system.

 

I only have the solar panels and the engine alternator. The alternator controller is adjustable but only up to about 15V. I have tried that but it did not seem to have much effect. Incidentally it tripped out the inverter.

 

N

Edited January 21, 2015 by Theo
Add the bit in parentheses.

[bizzard]

My point remains.

 

The number of Ah you need to generate depends not on how many batteries you have only on how many Ah you use between charges. If I have 2 batteries and they discharge to 50% then 4 batteries would discharge to 75% and 8 to 87.5%.

 

N

Yes quite but charging up 7 batteries from 50% at 1A is going to take about 60 hours of engine running.

[alan_fincher]

Is it "normal" for something sold as a leisure battery to specify MCA or CCA ?

 

"Cranking Amps" is surely only about its potential use as a starter battery?

 

I know there is often much debate about whether many of the batteries sold as "leisure" or "domestic", (which need to survive frequent partial discharge, but seldom deliver the kind of short hich currents necessary to start a diesel engine), are actually different from a starter battery, (which you would normally aim to discharge very little, and quickly restore to 100% charge). Ideally each type of battery would be internally very different, designed for the specific use it was sold for.

 

I suspect these may be in the category of what Gibbo used to describe as something like "starter batteries with a different sticker put on".

[Nickhlx]

I wonder if the light loading (charge and discharge) has allowed the electrolyte to stratify, and possibly the plates to partially sulphate.

 

Personally I have used Trojans ( 12V 440 Ah) and a Victron 12/3000/120 combi on a shoreline to look after them when not cruising - The alternator ( Iskra 175A) charges them at 14.8 Volts, and does get the majority of the Ah taken overnight back into them as quickly as probably possible, but even so you can't underestimate the time for the last 20% or so... This high charge rate / voltage has naturally ensured the cells get into gassing mode regularly which keeps the electrolyte well mixed. I am sure this has contributed to their longevity. A solar panel is a great addition for those not on a shoreline to ensure that 100% charge is maintained when not cruising...

 

One thing I am very aware of is the freshness / condition of the batteries at time of purchase - from a source with good turnover and purchased in the time of year when all the older ones have been sold there should be little need to check. but if you get a battery that is showing say only 12.4 volts when you buy it, how long has it been like this and is it already partly sulphated and so compromised in its longevity ?

 

I also subscribe to the idea that having only just the Ah that you need is preferable, as its cheaper to run fewer batteries, and those you do have should get worked a bit harder which is better than too much "molly coddling", even though it may be felt " kinder"

 

Nick

[bottle]

Seven domestics totalling 770Ah nominal at the 100hr

 

 

Just found this

 

Description Part No. Ah@20 Length (mm) Width (mm) Height (mm) Weight (Kg)

Sealed For Life DP/GP SFL85 85 260 169 225 19.5

Sealed For Life DP/GP SFL110 110 302 172 225 28

Sealed For Life DP/GP SFL120 120 328 172 240 30

 

 

So it looks like they are 110 amp.hr @ 20 hrs

 

That does not help you, sorry

 

Edit: format

Edited January 21, 2015 by bottle

[raymondh]

Do they have a two year warranty? however as your charging pattern may have caused them to prematurely suiphate and lose capacity your warranty claim could be rejected

Ray

Edited January 21, 2015 by raymondh

[George94]

I am a little surprised that you are running such a big bank down to 50% SoC.

 

Is there anything you can do to reduce your electrical consumption?

[David Mack]

Non expert view here:

 

If you have a large battery bank, and therefore only run the batteries down a little, then all of your recharging takes place at the point when the charge current is low, whereas for a smaller bank, more deeply discharged, a lot of the charging takes place at a higher current rate. So it will take longer to recharge the large bank than a small bank for the same amount of power used.

 

It follows that it is more likely that with a large bank, the batteries are not fully recharged at the end of a period of charging.

 

Persistent undercharging knackers batteries.

 

You now have a much lower capacity bank, and so even moderate use results in the SOC dropping more - hence the 50% levels you are seeing. The good news (I suppose) is that the charging is now more efficient and so the rate of deterioration should slow down, but the bad news is that your batteries have probably had it.

 

When you replace them, you would be better off saving some of your money and installing fewer batteries.

 

Have you done a power audit to see how much you actually need? If you really are boating daily and have solar power, then your battery requirement should be pretty low.

 

 

 

 

[forsberg]

Is not the main issue here Lead-Calcium and Maintance Free?

You will never manage to fully charge Calcium batteries as a continous cruiser.

( Unless perhaps if you have solarpanels and LPG fridge and turn anything else off during charging hours , the panels need to put more in then you take out)

Maintance-free is another word for will die as soon as lifespan goes out.

[Robbo]

Non expert view here:

 

If you have a large battery bank, and therefore only run the batteries down a little, then all of your recharging takes place at the point when the charge current is low, whereas for a smaller bank, more deeply discharged, a lot of the charging takes place at a higher current rate. So it will take longer to recharge the large bank than a small bank for the same amount of power used.

 

It follows that it is more likely that with a large bank, the batteries are not fully recharged at the end of a period of charging.

 

 

Incorrect, The charge will follow the charging curve, where you get on it depends on how long it will take to get to 100%. It may take longer to put more ah's in the closer you get to 100% but you still have to do that if you discharge to 50% or only 90%. A bigger bank expands the time you don't need to charge or reduces the amount you discharge the batteries by.

Edited January 21, 2015 by Robbo

[matty40s]

I recently (October) renewed my battery bank after 7 years good service from a set of Vinces second hand ones.

 

I found a way of equalising the old bank which involved a separate 100W solar panel through a manually adjustable (screwdriver!!)regulator. I did this over the last two summers which is why I think the bank lasted so well.

 

My new batteries were from a supplier which waters them when you order them - next day delivery. 6 x 120 AH batteries to replace the old 7 x 110AH.

I then booked a few days with a landline to ensure that the batteries were fully charged from day one....cycling them a couple of times, to make sure the smartgauge had the correct SOC.

Since then, they have never dropped below 55%, mostly solar charging, with occasional 2 hour engine running if I am not cruising and it is cloudy.

.

 

You will never manage to fully charge Calcium batteries as a continous cruiser.

( Unless perhaps if you have solarpanels and LPG fridge and turn anything else off during charging hours , the panels need to put more in then you take out)

 

I have electric fridge, and regularly have my batteries at 100% state of charge - almost daily in the summer, and even last weekend when I was away from the boat for 3 days.

[smileypete]

My point remains.

 

The number of Ah you need to generate depends not on how many batteries you have only on how many Ah you use between charges. If I have 2 batteries and they discharge to 50% then 4 batteries would discharge to 75% and 8 to 87.5%. (Assuming that is, you started at 100%)

 

N

 

Ah! Equalisation. That is what I cannot do easily with my system.

 

I only have the solar panels and the engine alternator. The alternator controller is adjustable but only up to about 15V. I have tried that but it did not seem to have much effect. Incidentally it tripped out the inverter.

 

N

Not always easy to do EQ 'off grid'...

 

One way could be to isolate a couple of batts at a time and use one of those £10 '600W DC converters' off EBay.

 

Or use a smallish unregulated solar panel. Some more details and ideas should be in the previous topics...

 

cheers, Pete.

~smpt~

Edited January 21, 2015 by smileypete

[Theo]

I am a little surprised that you are running such a big bank down to 50% SoC.

 

Is there anything you can do to reduce your electrical consumption?

The problem is that it is no longer a big bank. Soon after I fitted them I was running them down to about 85% unless we didn't move for a few days.

Do they have a two year warranty? however as your charging pattern may have caused them to prematurely suiphate and lose capacity your warranty claim could be rejected

Ray

I have just had a brief email from the suppliers saying that it may well be that they have given me the wrong advice in supplying me with that type. My correspondent says that he will have a word with the experts and get back to me.

 

That sounds hopeful.

 

N

Edited January 21, 2015 by Theo
fat fingers

[forsberg]

Continued:

Had to cut my post short so I didn't have time to elaborate , was just about to prove myself wrong more in detail Matty .

First I would like to point out that you cant say for certain that your batteries are fully charged unless they are at the stipulated charge voltage and draw almost no current with no load which might be one of the OP's problems.

 

So to get back to the original question:

If I understand Theo correctly he bought a big bank as to not have to run the engine daily.

Probably calculated for cycles of 100 to 50%.

As Rogeriko noted above the AGM's of the same line are classed for 400 cycles but probably compared against some really lousy batteries to make them look good so I hope the SFL's are a bit better then 100 cycles.

Anyway you need to give a little thought as to why 50%, it's not a magical number it's just a way of trying to tell how well buildt the battery are. Discharging to 60% will improve battery life but occationally dropping to 48 or 45 even will not make much diffrence.

So charging daily will improve battery life. but you would like to go down at least to 90% between to not have excess sulfation.

With a lead-cadmium battery you would also like to charge it to full at least once weekly and overharge it monthly or after 20 deep cycles to avoid sulfation.

As the "charge it to full" is not practical unless you cruise all day long, solarpanels are a good solution but you need to have enough to charge your batteries as well as to power your equipment.

Equalizing charge is a bit trickier but can also be made with the solar panels if you bypass your solar charge controller.

Not going into how to best do that, should probably be a thread of its own as there are quite a few dangers to avoid.

Lead-Calcium batteries also degrade faster if over 50C.

 

It could be worth to try a Equalizing charge fot for up tp to 3 days but at 1/6 capacity I'm afraid it is too late.

 

(Edited for when the whisky apparently kicked in)

Edited January 22, 2015 by forsberg

[matty40s]

My observations of solars effect on batteries, is that it helps prevent sulphation, even if the batteries are not brought back up to 100% SOC.

It does this by keeping the batteries stimulated, however small input they are giving, in the daylight hours.

 

I think Theo has an underlying hidden issue somewhere as the last set of batteries died and showed strange happenings, even in the longer daylight days.

[Loafer]

My observations of solars effect on batteries, is that it helps prevent sulphation, even if the batteries are not brought back up to 100% SOC.

It does this by keeping the batteries stimulated, however small input they are giving, in the daylight hours.

 

I think Theo has an underlying hidden issue somewhere as the last set of batteries died and showed strange happenings, even in the longer daylight days.

 

Agreed. Even with a current too low to provide a proper charge, solar panels keep the batteries above the doldrums, and reduce the usual undercharged-voltage effects.

[luctor et emergo]

Starter batteries are light (weight), used for high amps for a very short time, and recharge quickly.

 

proper domestic batteries are heavier, and discharged over a longer gradual time.

 

Forklift truck style batteries are very heavy, discharged to buxxery daily,, and last for years.

 

 

I dont understand why forklift batteries or trojans aren't standard leisure batteries on boats.