Battery Problems

[[2068]]

A bit of a fiasco on the battery front - these things don't happen due to just one thing going wrong, it takes a chain of events.

In this case:

- No 1 Daughter hits the wrong buttons on the Eberspacher control and programs heat on a regular basis instead of just firing it up for a few hours.
- I check the boat after she has been on it, and fail to spot this. It's not at all obvious.
- Storm knocks out shore power.
- Bloated battery inside "iSocket" means that I don't get a message that shore power has failed.
- Heater runs, uses 100L+ of Diesel, and drains the domestic battery bank to less than 8v.
- I check the boat a couple of weeks later, and try to re-charge the batteries, but the charger goes bananas throwing out 40A+.
- Starting the engines causes the ammeter to go off the scale.

- Things have settled down - the domestic bank is 13v+ and the charge current small.
BUT
all the "magic eye" indicators on the domestic bank have gone black / clear

I don't want to risk a battery explosion ... I am guessing I have cooked the batteries?
(they are sealed lead acid ... no obvious way to top up)

At least the inside of the boat has been nice and toasty for the last few weeks :ambivalence:

.

 

[volvopaul]

A bit of a fiasco on the battery front - these things don't happen due to just one thing going wrong, it takes a chain of events.

In this case:

- No 1 Daughter hits the wrong buttons on the Eberspacher control and programs heat on a regular basis instead of just firing it up for a few hours.
- I check the boat after she has been on it, and fail to spot this. It's not at all obvious.
- Storm knocks out shore power.
- Bloated battery inside "iSocket" means that I don't get a message that shore power has failed.
- Heater runs, uses 100L+ of Diesel, and drains the domestic battery bank to less than 8v.
- I check the boat a couple of weeks later, and try to re-charge the batteries, but the charger goes bananas throwing out 40A+.
- Starting the engines causes the ammeter to go off the scale.

- Things have settled down - the domestic bank is 13v+ and the charge current small.
BUT
all the "magic eye" indicators on the domestic bank have gone black / clear

I don't want to risk a battery explosion ... I am guessing I have cooked the batteries?
(they are sealed lead acid ... no obvious way to top up)

At least the inside of the boat has been nice and toasty for the last few weeks :ambivalence:

.

I wouldn’t bin them yet , I’ve never been a fan of batteries with window indicators as they are unreliable.

I’d change them and monitor over next few weeks , if they drop without the charger on then you know they are in discharge mode .

 

[rafiki_]

David, the batts are likely to have cooked. No downside of trying to charge, but you must monitor temp, as if plates have welded then the batts can cook and explode.

 

[[2068]]

David, the batts are likely to have cooked. No downside of trying to charge, but you must monitor temp, as if plates have welded then the batts can cook and explode.

Exploding sounds like a bad thing.

 

[rafiki_]

Exploding sounds like a bad thing.

Yes, not a great thing to clear up. One of my batts got very close, and I was lucky enough to capture it and disconnect before it made a real mess. This is why you should monitor when you charge iffy batteries. I would only charge iffy batteries if I were present to disconnect if they started warming up.

 

[halcyon]

- Things have settled down - the domestic bank is 13v+ and the charge current small.
BUT

Put cabin lights on and watch the battery voltage, if it drops then settles to approximately a steady voltage you may have got away with it, if the voltage keeps falling the batteries are shot, May take an or more depending on load.

Thought the heater had a low voltage cut off ?

Brian

 

[[2068]]

Thought the heater had a low voltage cut off ?

100 litres of diesel disappearing from my port tank and a domestic battery bank at 8v suggests that it didn’t :ambivalence:

 

[BartW]

after diconnecting the charger,
with no load, the voltage should stay for a while, (a number of day's) above 12V,
if they quickly go below 12V they are bad,

 

[Rocksteadee]

The batteries being cooked would have come from over charging, more like I suspect that they have been discharged below their recoverable level.
They may charge back up but are unlikely to sustain an output for any considerable discharge

 

[QBhoy]

Likely one of them is toast and ruining the other.
Apart from that...I’m amazed the heater was allowed to do that. They normally cut out if they detect a low power supply and don’t start of three do too. Amazing that the batteries managed to recover Enough each time to go through 100 litres and do that to batteries. Are you sure something else isn’t going on too ?

 

[[2068]]

Likely one of them is toast and ruining the other.
Apart from that...I’m amazed the heater was allowed to do that. They normally cut out if they detect a low power supply and don’t start of three do too. Amazing that the batteries managed to recover Enough each time to go through 100 litres and do that to batteries. Are you sure something else isn’t going on too ?

What else do you suggest consumed 100Litres of diesel, 300Ah, and kept the interior warm?

 

[halcyon]

100 litres of diesel disappearing from my port tank and a domestic battery bank at 8v suggests that it didn’t :ambivalence:

Did find this snippet ...

When the voltage at the Eberspacher drops to 10.5 volts lasting for 20 seconds it shuts down. (10.2 volts for some models) During starting the glow plug takes about 8 amps for a D2 or D4, the older models take about 20 amps. This is when the voltage drop will be worst and most low voltage problems occur. The usual symptom is the heater fan runs for about 20 to 45 seconds during starting, then the unit shuts down.

Note this voltage must be measured at the Eberspacher, the voltage at the battery end of the cables will be higher. The voltage can drop below 10.5 volts and not shut down the heater if it starts before 20 seconds.

As the battery discharges lower voltage can cut the heater off when running. In each case it will usually make another attempt to start. See Testing - Using a digital voltmeter or multimeter section for testing.

Eberspacher quote all electrical measurements can vary by 10%, however the voltage cutoffs are set quite accurately.

Not clear though if startup, running or both.
Brian

 

[gordmac]

Brother used to run batteries down dead flat regularly with a bilge pump, charge them up and carry on using them. They lose capacity but keep going for a surprisingly long time before being completely knackered.

 

[Rocksteadee]

Brother used to run batteries down dead flat regularly with a bilge pump, charge them up and carry on using them. They lose capacity but keep going for a surprisingly long time before being completely knackered.

That is the quickest way to knacker the batteries. A 12v lead acid battery is considered fully discharged at 10.7volts. Any discharge lower than this starts to cause irreparable damage and severely shortens its life

 

[BruceK]

That is the quickest way to knacker the batteries. A 12v lead acid battery is considered fully discharged at 10.7volts. Any discharge lower than this starts to cause irreparable damage and severely shortens its life

That is the wisdom of the internet and battery lore. Surprisingly empirical observation is often at odds with that especially with more modern batteries and of course lets not forget deep cycle batteries.

 

[[2068]]

An update:

I left the whole lot disconnected for a week or so, and powered things back up.
Without any additional charging, the domestic bank was still around 13v.
I switched on the charger, and it charged at a lowish rate for 20 minutes before dropping happily into Float Mode.
(bear in mind the ammeter was hard off the RHS of the scale when I first tried to recharge).

I was checking the battery temperatures during charging - all cold.
Even better, the little indicator eyes have all gone green again.
So I think I will continue to these batteries for the moment, and see how things go.

 

[[2068]]

I also fixed the iSocket with a new liPo internal battery.

Here’s a Marina Etiquette question:

- When your shore power trips, and you pop round to investigate, what do you say to the person that has just disconnected your boat and has plugged their sanding machine into your metered lead?

 

[jamie langstone]

I also fixed the iSocket with a new liPo internal battery.

Here’s a Marina Etiquette question:

- When your shore power trips, and you pop round to investigate, what do you say to the person that has just disconnected your boat and has plugged their sanding machine into your metered lead?

Unplug them a wait until they arrive at the plug and inform them of there error and wait for there response before you let rip in a Etiquette way .