Batteries

[RichardtheGardener]

Hello all, 

 

When we went to view our boat before buying her, she had three 135 ah leisure batteries but no starter. 

 

The surveyor suggested that one battery is split from the rest as a starter which is what happened before we picked her up. 

 

 Since having her, I think I can now see why the previous owner had the three and no starter. There is a 240v battery charger wired up to the batteries and a honda generator onboard. I thinking that in the unlikely event that the previous owner forgot to run their engine to charge up the batteries and therefore the batteries ran too low to start the engine that he would just charge them up using the gennie. 

 

We have never run out of power in the 15 months we have been aboard, but do notice the lights dim after 12 hours or so if we turn another appliance on and sometimes the fridge is flashing for low power the next morning. 

 

I am thinking of changing it back to the old system of having the 3 x 135 ah batteries as leisure batteries again. What considerations should I take into account before I do? 

 

Cheers, 

 

Richard 

[rusty69]

If you have room, i would get a smaller capacity engine start battery and add the larger battery to the house bank. 

[Phil Ambrose]

1 minute ago, rusty69 said:

If you have room, i would get a smaller capacity engine start battery and add the larger battery to the house bank. 

What he said plus get some sort of battery management/monitoring kit in place 

Phil 

[Tony Brooks]

28 minutes ago, rusty69 said:

If you have room, i would get a smaller capacity engine start battery and add the larger battery to the house bank. 

 

26 minutes ago, Phil Ambrose said:

What he said plus get some sort of battery management/monitoring kit in place 

Phil 

Yes, the dimming light and the fridge flashing suggests the three batteries do not have enough capacity for your needs or you arn't charging them enough so getting rid of one will only make the situation  worse - those symptoms will appear sooner.

 

The other possibility is the batteries are so sulphated the only have a fraction of their original capacity or one has a small short circuit in a cell but that is less likely. Both are age related but sulphation is caused by leaving batteries never fully charged and shorts can be caused by constant over discharging.

 

My  diagnosis is very tentative because sub standard wire sizing can also cause those symptoms.

[Dr Bob]

You should never 'run out of power' with lead acids. You shouldn't take them below 50% full otherwise their life will be shortened. The is a battery primer thread. Read that. It is important if you want to have a decent life out of you batteries. 

At minimum get a voltmeter so you can see the voltage but if you can put a battery monitor on which measures current and amp hours used, that will be the best solution. 

Im sure someone will be along with a link to the battery primer thread soon.

Edited August 26, 2018 by Dr Bob

[rusty69]

12 minutes ago, Dr Bob said:

 

Im sure rusty will be along with a link to the battery primer thread soon.

 

Edited August 26, 2018 by rusty69

[Dr Bob]

I knew she'd show up.

[rusty69]

Just now, Dr Bob said:

I knew she'd show up.

Hey. I've been here since 0730 pal, while you were dreaming of miss piggy! 

[MtB]

12 minutes ago, rusty69 said:

Edited 7 minutes ago by rusty69

 

HAY you cheated!!

 

 

[Alan de Enfield]

1 hour ago, RichardtheGardener said:

What considerations should I take into account before I do? 

1) What condition are the existing batteries in ?

2) Can you reduce your electrical consumption ?

3) If you are not charging 2 batteries sufficiently, what do you intend to do to be able to charge 3 ?

 

Batteries are only storage vessels, you must put back in more than you take out.

[RichardtheGardener]

Thanks all. At the start of September, we will be adding solar which we are sourcing from Bimble. 

 

I have started reading the battery priming thread but will go through it proper later with a cuppa, Thanks for that. 

 

R 

[MtB]

26 minutes ago, Dr Bob said:

You should never 'run out of power' with lead acids. You shouldn't take them below 50% full otherwise their life will be shortened. The is a battery primer thread. Read that. It is important if you want to have a decent life out of you batteries. 

 

This thread got me thinking/musing/remembering about how I and my peers used to treat batteries decades ago when we knew nothing about all the stuff in Wotever's battery primer.

 

Firstly, we had 'a battery' rather than a bank of three or four. Secondly the only work the battery had to do was water pump, shower drain pump and the occasional light in the bedroom and shower room. We had gas lights in the saloon and galley, and a gas fridge. And we used to run the battery until the lights went dim or the water pump refused to work, then fire up the Honda genny for two or three hours to charge it for a random period, and this would last a day or two or three depending on how much petrol we had put in the genny before going down the pub.

 

I seem to remember a battery lasting a year or two with this treatment and given the regime, I'd say we were typically discharging down to about 5% or 10% SoC on every cycle (dim lights and pumps refusing to run) then charging to perhaps 50% or 60% SoC then repeating the cycle. None of us had volt meters or fancy stuff like that, we just knew the practical SoC of our batteries from how long it was since we last gave them a charge and how long it was for. 

 

The thing is, batteries still seemed to last a year or two with this cruel treatment, contrary to current wisdom that one should never discharge below 50% for max battery life.

 

The OP's problem is different though. His are goosed every morning, not goosed after too few years of use.  

 

And I suspect there are still a lot of boaters out there who still do it our old way, i.e. discharge until the lights go dim, then charge up for a bit, wait for the dim lights, recharge, etc et.

[mrsmelly]

16 minutes ago, RichardtheGardener said:

Thanks all. At the start of September, we will be adding solar which we are sourcing from Bimble. 

 

I have started reading the battery priming thread but will go through it proper later with a cuppa, Thanks for that. 

 

R 

Are you going to chop those trees down at your mooring old sport before you fit the solar? ?

[nicknorman]

15 minutes ago, Mike the Boilerman said:

 

This thread got me thinking/musing/remembering about how I and my peers used to treat batteries decades ago when we knew nothing about all the stuff in Wotever's battery primer.

 

Firstly, we had 'a battery' rather than a bank of three or four. Secondly the only work the battery had to do was water pump, shower drain pump and the occasional light in the bedroom and shower room. We had gas lights in the saloon and galley, and a gas fridge. And we used to run the battery until the lights went dim or the water pump refused to work, then fire up the Honda genny for two or three hours to charge it for a random period, and this would last a day or two or three depending on how much petrol we had put in the genny before going down the pub.

 

I seem to remember a battery lasting a year or two with this treatment and given the regime, I'd say we were typically discharging down to about 5% or 10% SoC on every cycle (dim lights and pumps refusing to run) then charging to perhaps 50% or 60% SoC then repeating the cycle. None of us had volt meters or fancy stuff like that, we just knew the practical SoC of our batteries from how long it was since we last gave them a charge and how long it was for. 

 

The thing is, batteries still seemed to last a year or two with this cruel treatment, contrary to current wisdom that one should never discharge below 50% for max battery life.

 

The OP's problem is different though. His are goosed every morning, not goosed after too few years of use.  

 

And I suspect there are still a lot of boaters out there who still do it our old way, i.e. discharge until the lights go dim, then charge up for a bit, wait for the dim lights, recharge, etc et.

I suspect the point is that with such minimal demand as you describe, you didn’t notice when the batteries lost a massive chunk of their capacity. It was perhaps only when they got down to 25% of their capacity that you finally splashed out on a new one.

 

Incidentally, just checked my Trojans. sg all 1.280 within a small margin, at 27C. (slightly higher than spec due to needing a little bit of water). So no sulphation and still giving full capacity now after 5 years. I haven’t equalised them at all this year.

Edited August 26, 2018 by nicknorman

[MtB]

1 minute ago, mrsmelly said:

Are you going to chop those trees down at your mooring old sport before you fit the solar? ?

 

And another point, I wouldn't bother getting solar until next spring now, rather than shelling out for it next month. God turns the solar electricity OFF in the winter months so yours will just sit there doing nothing.

 

People say it just drops off a bit in winter but no this is not in my experience. My 560W of solar is brilliant in summer but delivers negligible charge in the four shortest months of the year. 

[Tony Brooks]

8 minutes ago, Mike the Boilerman said:

 

Snip

 

And I suspect there are still a lot of boaters out there who still do it our old way, i.e. discharge until the lights go dim, then charge up for a bit, wait for the dim lights, recharge, etc et.

 

Absolutely and if you are willing to consider batteries consumables to replaced every year or two then its a fair way of working but we have regularly had new livaboards on who destroy batteries in a very few weeks so it makes sense to get informed and then decide how much trouble you want to put into maximising battery life. I am very happy with just a voltmeter and ammeter but agree that one of the amp hour counter gauges is just as good and in one respect better as long as you ignore Ah left and percentage charged. Once you get to know the voltage readings expected from your own boat then its not much trouble keeping an eye the state of charge etc. but you have to gather that knowledge first.

 

22 minutes ago, RichardtheGardener said:

Thanks all. At the start of September, we will be adding solar which we are sourcing from Bimble. 

 

 

If you do start monitoring your battery voltage to assess state of charge remember not to do it when the solar is producing any output. If you do you will think the batteries are far better charged than they really are.

[George and Dragon]

It seems to me that if a proper battery monitoring system were in place to prevent any further discharge once the LAs get to 12.2V there would be no need for any of us to have a separate starter battery.

[MtB]

31 minutes ago, nicknorman said:

I suspect the point is that with such minimal demand as you describe, you didn’t notice when the batteries lost a massive chunk of their capacity. It was perhaps only when they got down to 25% of their capacity that you finally splashed out on a new one.

 

Probably right, but my perception is that modern el cheapos sulphate a lot more easily and quickly than those car batteries we were using 40 years ago. 

 

I bought a pair of domestic batts for one of my hobby boats last summer, and after leaving them at perhaps 60% SoC (i.e. not fully charged) for two weeks just ONCE (I simply did not have time to charge before leaving the boat, and no solar then), they were spectacularly goosed on resuming using them. 

 

 

25 minutes ago, George and Dragon said:

It seems to me that if a proper battery monitoring system were in place to prevent any further discharge once the LAs get to 12.2V there would be no need for any of us to have a separate starter battery.

 

I think this too. Have a greeny!!

 

The separate starter batt is really only a hangover from when everyone used the OLD SKOOL 'dim lights' method of battery monitoring. 

 

And those of us who carry a genny even then still don't need a separate start batt. 

 

Edited August 26, 2018 by Mike the Boilerman
Delete accidental ALL CAPS

[Dr Bob]

24 minutes ago, Mike the Boilerman said:

 

And another point, I wouldn't bother getting solar until next spring now, rather than shelling out for it next month. God turns the solar electricity OFF in the winter months so yours will just sit there doing nothing.

 

People say it just drops off a bit in winter but no this is not in my experience. My 560W of solar is brilliant in summer but delivers negligible charge in the four shortest months of the year. 

.....and bugger all today!

[roland elsdon]

36 minutes ago, Mike the Boilerman said:

 

This thread got me thinking/musing/remembering about how I and my peers used to treat batteries decades ago when we knew nothing about all the stuff in Wotever's battery primer.

 

Firstly, we had 'a battery' rather than a bank of three or four. Secondly the only work the battery had to do was water pump, shower drain pump and the occasional light in the bedroom and shower room. We had gas lights in the saloon and galley, and a gas fridge. And we used to run the battery until the lights went dim or the water pump refused to work, then fire up the Honda genny for two or three hours to charge it for a random period, and this would last a day or two or three depending on how much petrol we had put in the genny before going down the pub.

 

I seem to remember a battery lasting a year or two with this treatment and given the regime, I'd say we were typically discharging down to about 5% or 10% SoC on every cycle (dim lights and pumps refusing to run) then charging to perhaps 50% or 60% SoC then repeating the cycle. None of us had volt meters or fancy stuff like that, we just knew the practical SoC of our batteries from how long it was since we last gave them a charge and how long it was for. 

 

The thing is, batteries still seemed to last a year or two with this cruel treatment, contrary to current wisdom that one should never discharge below 50% for max battery life.

 

The OP's problem is different though. His are goosed every morning, not goosed after too few years of use.  

 

And I suspect there are still a lot of boaters out there who still do it our old way, i.e. discharge until the lights go dim, then charge up for a bit, wait for the dim lights, recharge, etc et.

Yep wait till the incandescent bulbs go to an orange glimmer then either go to bed or start up the gennie. Did it for years and batts used to survive. We used to have 2 times 10 amp chargers 1 stage, off honda ex650. Batteries probably never more than 75% charged.

however now ipad 2.1 amp charge rate

iphone 1 amp charge rate and electric fridge ( circa 20 amps discharge a day) and its no wonder batteries die.

i think batteries were possibly slightly more robust, lets face it in the downward spiral of price quality always suffers.

our butty also for obvious reasons never subjected the engine start battery of the 80s and 90s to heavy loads , it wasnt until leisure batts started to be ‘the thing’ that ive noticed issues. Elecsols were my first big financial disaster , the replacement midland chandlers  cheapy batteries lasted twice as long

[MtB]

17 minutes ago, roland elsdon said:

i think batteries were possibly slightly more robust, lets face it in the downward spiral of price quality always suffers.

 

I definitely think you've put your finger on it here. I bet all batteries were made like Trojans back in the day and resisted sulphation robustly. They were certainly priced accordingly.

 

It's only since low cost 'leisure' batteries became a thing that I too have noticed all the battery issues emerging. 

 

 

 

 

Edited August 26, 2018 by Mike the Boilerman

[nicknorman]

38 minutes ago, George and Dragon said:

It seems to me that if a proper battery monitoring system were in place to prevent any further discharge once the LAs get to 12.2V there would be no need for any of us to have a separate starter battery.

Unfortunately it’s not that simple. The 12.2v or whatever is the RESTED, NO LOAD voltage, not the instantaneous voltage. We regularly have our batteries down to 11.5v or so - when I put the electric kettle or coffee machine on, and with the SoC close to 100%. This is also why using the inverter low voltage warning as a guide that the batteries are flat doesn’t work unless you never take significant current out of the batteries.

Edited August 26, 2018 by nicknorman

[nicknorman]

10 minutes ago, Mike the Boilerman said:

 

I definitely think you've put your finger on it here. I bet all batteries were made like Trojans back in the day and resisted sulphation robustly. 

 

It's only since 'leisure' batteries became a thing that I too have noticed all the battery issues emerging. 

 

 

I think it is because of the popularity of lead calcium plates these days, instead of the lead antimony plates of old (and of present day Trojans).

 

The calcium is added in part to reduce gassing and hence reduce or eliminate the need to add water - maintenance free etc. My experience of leisure lead calcium batteries is that they sulphate very easily even when fully charged regularly at typical alternator voltages of 14.4v. They really need 14.8v or so to keep sulphation at bay - and then of course they start to use water!

 

Did i mention that I like my lead-antimony Trojans even though I have to add water 2 or 3 times a year??

[mrsmelly]

6 minutes ago, nicknorman said:

Unfortunately it’s not that simple. The 12.2v or whatever is the RESTED voltage, not the instantaneous voltage. We regularly have our batteries down to 11.5v or so - when I put the electric kettle or coffee machine on, and with the SoC close to 100%. This is also why using the inverter low voltage warning as a guide that the batteries are flat doesn’t work unless you never take significant current out of the batteries.

I've been on the ops boat he has a gas stove so would never use an electric kettle straight from the batteries through an inverter! Isn't that a bit like smacking your head on a brick wall and wondering why it hurts?

[Dr Bob]

My strategy for avoiding low SoC and low voltage is to have more capacity. With 6*110Ahr cheapo's, and using at most 120Ahr overnight (and usually 80Ahr) in non camping mode, we very very rarely get down to less than 80% SoC although half the time in winter we are on shore power. We dont need a starter battery but I will replace my 10 year old one this winter just in case.