catastrophic battery failure !

[Strolls]

Id go with this answer - once one battery drops a cell for whatever reason if not noticed fairly early on you can pretty much guarantee it will kill the other battery as well - it's good practice to change both batteries at the same time or you will continually have one old battery "killing" the new one after a fairly short period of time.

So am I right in understanding that if a battery in your house bank drops a cell, you only really have two choices:

1. Replace the whole house bank.
2. Remove the dead battery and accept you now have a smaller reserve of battery power.

Sorry to ask a dumb noob question, but I just wanted to be completely clear.

 

[duncan99210]

F

So am I right in understanding that if a battery in your house bank drops a cell, you only really have two choices:

1. Replace the whole house bank.
2. Remove the dead battery and accept you now have a smaller reserve of battery power.

Sorry to ask a dumb noob question, but I just wanted to be completely clear.

Ask understand it, as a temporary measure, once you've identified the battery with a dead cell you should remove it from the bank. Then replace it. However, if sufficient damage has been caused to the remaining batteries (ie they will no longer hold a charge) then you will need to replace all of them.

 

[ribrage]

F

Ask understand it, as a temporary measure, once you've identified the battery with a dead cell you should remove it from the bank. Then replace it. However, if sufficient damage has been caused to the remaining batteries (ie they will no longer hold a charge) then you will need to replace all of them.

imagine your battery's as huskies in a sled team, you buy ten puppy's with a working life expectancy of five years you couple them to your sled and off you go - after five years one of them dies and your other huskies are now dragging his ass along AND coping with the weight of the sled - they are working harder so another one dies

so you buy another puppy and put it in with all those old dogs - the puppy wants to pull that sled and work hard but the old dogs hold him back, so he plods along at the same speed as the old dogs - as more old dogs die you slowly replace them with puppies now all at different ages and never working that sled as well as the matched team you started with

once my five year old battery croaks I KNOW the others aren't far behind - if they have all been boiled dry and internal plates exposed my experience is filling them with water and recharging them is a short term fix and one that will bite you on the ass in the not to distant future.

my preferred method is to shoot the old dogs and buy all new puppies

but that's just me.

 

[OldBawley]

If the OP has been running a fridge from his battery´s and only charged with solar, two things come to mind.
First : two years means 365 X 2 = 730 discharges or cycles. Most batt manufacturers give less than 730 cycles as a life expectancy.
Second : Charging batts is a four step process. The last step to get 100% charge is charging very little but for a long period. I read equalising can take up to 10 hours.
Since in winter there is only about 6 to 8 hours of sun available, a solar charged system can never charge to 100 % With other words, decay starts.
Wind charging can help, if wind is available during the night.
Charging with a generator or running the engine, just good for charging the bulk, and that is simply not enough.

People who claim 5 or 7 year old batts are no liars. Perfectly possible. You just make sure the boat is 24 h / day onto shore power or the yacht is decommissioned six months a year.

 

[macd]

First : two years means 365 X 2 = 730 discharges or cycles. Most batt manufacturers give less than 730 cycles as a life expectancy.

I know where you're coming from, OB, and you make good points. But to suggest that the batteries go through a full cycle daily is in most cases wrong. During typical Med summer days my batteries, for instance, are rarely depleted by more than 15%. (Even this morning they were only about - 12%, largely because the fridge is less power hungry in November temperatures .) This figure can get higher on successive cloudy days/at season's end, but even then I rarely see them more than 35% depleted. Obviously the demands on batteries would be greater in winter, but I'm usually on shore-power then.

To the OP: to my mind a "catastrophic" battery failure would involve fire or explosion (which is what I anticipated reading about when I opened this thread). Your situation is certainly a bummer, but I hope that any fture catastrophe which befalls you is as harmless

 

[OldBawley]

I have seen fridges use up to 50 Ah /day. You need a lot of solar to charge that back in 6 to 8 hours. Don't forget, during charging in daytime the fridge is running also, diminishing the charge rate considerately.
Consumption 50Ah, Peukerts principle, you need to charge 60 to 65 Ah to be at back at 100 %

An other thing witch is often ignored is the age of the batts.
Buying “New” batt´s does not mean buying good batt´s. I know chandlers who store batt´s sometimes for more than a year before they get sold and forget to keep them charged.
So called “new” batt´s can be already down to 80 % of their capacity and life.

 

[charles_reed]

I have seen fridges use up to 50 Ah /day. You need a lot of solar to charge that back in 6 to 8 hours. Don't forget, during charging in daytime the fridge is running also, diminishing the charge rate considerately.
Consumption 50Ah, Peukerts principle, you need to charge 60 to 65 Ah to be at back at 100 %

An other thing witch is often ignored is the age of the batts.
Buying “New” batt´s does not mean buying good batt´s. I know chandlers who store batt´s sometimes for more than a year before they get sold and forget to keep them charged.
So called “new” batt´s can be already down to 80 % of their capacity and life.

I'd support some of the points being made:-

1. Despite 330 w of PV panel, my 300 AH of batteries never achieve full charge on solar alone.
2. I don't buy batteries from those who can take them off the shelf, preferring people who need time to fill electrolyte and fully charge the replacement batteries.
3. In high summer @ 35N, I have to allow 80AH for my fridge which drops to about 30AH in April.

PS Witches, I thought, were mythic creatures who rode on brooms (or in Scandanavia on spruce branches) ;-)

 

[macd]

1. Despite 330 w of PV panel, my 300 AH of batteries never achieve full charge on solar alone.

My 340W are certainly capable of fully charging 450Ah of batteries (subject to morning state of charge and sufficient sunshine, obviously). The difference probably lies in the controller.

 

[OldBawley]

I bought a state of the art MPPT controller.
Not impressed.
I don't believe a electronic circuit can change laws of physics.
Hope witches can.

 

[DaiB]

This is what I call a catastrophic failure.


http://www.ybw.com/forums/images/icons/icon6.png

 

[macd]

I don't believe a electronic circuit can change laws of physics.

It doesn't need to...any more than a battery charger can.
You do believe that battery chargers can charge batteries, don't you?

 

[charles_reed]

My 340W are certainly capable of fully charging 450Ah of batteries (subject to morning state of charge and sufficient sunshine, obviously). The difference probably lies in the controller.

At what point do you consider the batteries fully charged? Unless you check with hydrometer, your's can only be considered an unfounded and wishful opinion.

If it's just got to float, you're kidding yourself.

My MPPT controller is a BZ 500, set to float @ 14.4v and having an input @ 24v.

 

[macd]

At what point do you consider the batteries fully charged? Unless you check with hydrometer, your's can only be considered an unfounded and wishful opinion.

If it's just got to float, you're kidding yourself.

Thanks for the advice, Charles. I'll see if I can borrow a hydrometer.

Oh, what's this? It seems I already have one, and I've already used it on a regular basis...but obviously only in an unfounded and wishful way.

A little bit presumptuous, aren't you?

 

[charles_reed]

Thanks for the advice, Charles. I'll see if I can borrow a hydrometer.

Oh, what's this? It seems I already have one, and I've already used it on a regular basis...but obviously only in an unfounded and wishful way.

A little bit presumptuous, aren't you?

Well tell us all how you deem your batteries fully charged.
If it can't be measured it's just an assertion.

 

[macd]

Well tell us all how you deem your batteries fully charged.
If it can't be measured it's just an assertion.

It comes as a major surprise to discover than someone with your background is actually reading-impaired. Now concentrate really hard and try reading post #33 again.

 

[OldBawley]

Instead of arguing, I did some measuring.
My MPPT ( German made IVT 20 amp Mppt regulator )
If I keep the fridge running at night our consumption during dark hours is is about 30 ah.
During loading our MPPT regulator starts cutting down the currant / voltage at 14,1 V .Currant is regulated down from approximately 8 amps to 2 or 3 A/h. The Amp/ hour meter tells me some 15 A/h still need to be charged. Probably means 20 AH, .( Peukerts )
So the last 20 A/h are been charged at 2 to 3 Amps, not to exceed the magical 14,1 ( On the exit of the regulator ) That means then hours !
In Float mode the tension goes up to 14,3V.
Today ( November ) was a sunny cloudless day. Nine hours of sun, of which only seven delivered currant. With the sun just above the horizon our panels deliver zip.
We have little consumption since I stop the fridge at sundown. Laptops have SSD, use only one A/h. Only led lights. At 7 this morning AH meter measured minus 15Ah.
We have 170 w pv, means in practice 8 A minus 3 A direct consumption = 5 Ah.
Bulk was fast, at noon bulk was completed. That left 4 hours of sunshine for absorption charge.
Nearing sundown our AH meter was convinced the batt´s ware full, still 2 amps ware been charged.

Conclusion, with 170 w pv, a very low consumption fridge ( Ours uses 24ah/ day ) and low direct consumption ( 2 ah ) the hours of current bringing sun is just not enough.
Summer with 15 h of sun is no problem.

 

[macd]

Conclusion, with 170 w pv, a very low consumption fridge ( Ours uses 24ah/ day ) and low direct consumption ( 2 ah ) the hours of current bringing sun is just not enough.
Summer with 15 h of sun is no problem.

Yes, OB, and thanks for the detailed description. That tallies with my experience, too (backed-up, for the sake of the semi-literate, by hydrometer readings).

 

[grafozz]

Are all your panels connected through a regulator of some sort - PWM or MPPT type. If so I suspect that something has gone wrong with the regulator and there may well be 18 or 19 volts going in but possibly there's precious little coming out?
free online store builder

one of the regs is showing "full " which is apparently not the case , so maybe this one is faulty ?
It will be replaced with the same type as the port bank , mppt type .

Meanwhile , back in the bowels of the batteries , the one that had dropped to 3-5 volts is now on charge in the garage , but it looks like the patient has terminal (sic) failure , when the charger leads are removed the volts drop quickly so it is destined for the bin / recycler .

 

[grafozz]

Re: catastrophic battery failure ! update 11/11/2015

the suspected anchor windlass demanding of power was not the case , it was the starter motor trying to engage !
I took it out to find the solenoid had totally burned out .
collected the rebuilt motor complete with new solenoid from a local car guy for a very reasonable 60 e
and its going back in tomorrow .
Was this the cause of the battery failure or one of the symptoms ?
The duff battery was replaced and
all remaining batteries are now fully charged 1290/1300 , just using the solar panels , luckily we have had full
days of sunshine for quite a while so good for recovery .
the dud battery is less than a year old and it has swollen sides ? what does this represent ?

thanks all ,

 

[RichardS]

Are all your panels connected through a regulator of some sort - PWM or MPPT type. If so I suspect that something has gone wrong with the regulator and there may well be 18 or 19 volts going in but possibly there's precious little coming out?
free online store builder

Oh ... it's so nice to be copy and pasted by a spam bot. Brilliant. Post reported.

Richard