Battery question

[beancounter]

Numpty question.

Down at the boat on Saturday, the domestic battery seems to have given up the ghost - nothing would work when the battery switch was set to 2, but was fine on 1 (the engine battery). Battery 2 was showing around 10 - 11v on the meter in the instrument panel, but when I turned the battery charger on, no charge was accepted (the charging light on the battery charger stayed off).

My immediate reaction was that the battery was finished, and I would need to buy another. Second thoughts, however, make me wonder if there is a problem with the charger. Do batteries just "go"? (I hadn't noticed any decline in the performance over the season).

Any thoughts?

Bearing in mind that :

a) I don't have a wiring diagram of these circuits.

b) I'm not too hot on this electrickery stuff

ta

John

 

[Jonny_H]

John,

I'm no expert but our engine battery 'went' this summer. It had been fine all year - only 2 years old. It started the engine every day for 5 weeks and was holding good charge (12.5v after an hour of alternator charge). We motored for a couple of hours into the Isle of Man on the penultimate day of our visit and on arrival it showed 12.4v. Next morning we came to leave and it wouldn't turn the engine over! Started the engine off the domestic bank and ran it for a while. Engine battery recovered from 9v to 12.6v during the motor back to Fleetwood, but was back to 8.6v next morning.

Checked all the wiring - no problem. Battery just died!

So, in short, from my experience, they can just 'die'!

Jonny

 

[neale]

Alot of modern chargers won't try and put charge into a battery it thinks has had it. I have got around this by charging it using a standard basic car charger for a few hours to put some life back into it, then switching over to the marine unit which on detecting some life, starts to charge.

 

[Piers]

Sounds like one of the 6 cells that make up the 12v battery has died, which would give you the readings you state. If so, you need a new battery.

 

[neale]

Yes of course that is a possibility. I was working on the assumption it had simply drained down due to something being left on.

Need to use a hydrometer thingy on each cell to detect if you have a dead cell.

 

[beancounter]

[ QUOTE ]
Need to use a hydrometer thingy on each cell to detect if you have a dead cell.

[/ QUOTE ]

I was going to have a quick look at the battery before I left, but when I got the torch out of the locker, it's batteries were dead.....

 

[Jonny_H]

If you take it to an autoshop they can test it (usually for free) and tell you if its dead. However in my experience they nearly always tell you its a gonna to try and squeeze a sale out of you (I've had 'dead' domestic batteries that have (with limited capacity I must admit) have lasted a further 12 months).

Jonny

 

[beancounter]

Thanks, Jonny.

Looks like I'm getting a new battery for Christmas.
Woohoo.

Watch out for a "Which battery is best? thread in the New Year...


John

 

[Jonny_H]

You lucky thing!! We went for Lifelines for the domestic bank and then just got a Wet Cell for the Engine. We ended up with a truck battery from Tanya (google them) - it was a Numax one - they do a marine version too but not in the size / capacity layout we needed.

We put together a birthday / xmas list for SWMBO and I - SWMBO ended up with Nigel Calders 'Marine Diesel Engines' last week for her birthday - she is so lucky!!!

Jonny

 

[sailinglegend420]

It sounds like a dead charger - or blown fuse in the charger. Try switching to battery 1 and turn on the charger and see if the volts go up - if not the charger is dead. Our charger will switch off after so many hours of trying to raise the battery voltage - but a charger should at least try and charge for a while untill it decides to give up.

 

[beancounter]

The charger's power light was "on", so power must have been getting as far as the unit. It did initially show the "charging" light, but that soon disappeared.

So maybe the charger tried the battery for a while, and then gave up.

 

[Como]

Yes batteries can suddenly fail.

A couple of years ago we went down to Emsworth for our grandsons 18th birthday party, a journey that took over 2 hours so the battery should have been fully charged. Came out after the party and the battery would not even turn the engine over. I got a jump start and drove home (praying all the way that the engine did not cut out). When we got back I turned the engine off and then immediatly tried to restart - nothing! Got a new battery and have had no problems since which is what I suggest that you do.

John

 

[Boatman]

Sorry to sound so numpty...............

but what about a multimeter to test if there is a charge etc

could go on but,,,,,,

 

[jimbaerselman]

Whenever you have apparent battery failure, it always pays to check the connections first, positive and negative, all the way thru the system.