Battery Issues - Not charging

[jamiepyoung]

Following a rather rough passage last week, we returned to the marina and plugged the shore power back in as normal.

We noticed the next day that the leisure battery voltage had dropped to less than 12V and kept on dropping.

The charger was connected, lights on as usual, everything seemed fine.

We were going away for a couple of nights so turned everything off but left the batteries on charge. When we returned the leisure battery was dead, showing about 9v. We assumed the battery just needed replacing - it is probably a couple of years old and is heavily used.

We bought a new one yesterday, but now the voltage is dropping on that as well (less than 12v this morning) so I assume the charger or VSR is not working properly.

The set up is:

BEP Battery Monitor
Victron Phoenix charger
BEP VSR and switches etc

Everything has been fine up until now, so I'm wondering if the rough passage has caused a loose connection - any ideas on what to check?

Thanks!

 

[pvb]

If the charger is on, but the battery voltage is dropping, it would seem that either the charger is faulty, or the circuit from the charger to the battery is faulty. You'd check the wire to the battery first. You could also put a voltmeter on the charger output to see what voltage is there.

 

[jakeroyd]

Good suggestion from pvb.
get any cheap multimeter , set it to DCVolts and measure across the battery terminals whilst the charger is on.

You should see a voltage something like 13.5 which should rise to perhaps 14.5 slowly over maybe a few minutes.
If you don't there is a problem with the charger ?

BTW if the voltage gets down to about 10.8 volts the battery will be irreprably damaged so stop it discharging long before it gets anywhere near.

 

[jamiepyoung]

BTW if the voltage gets down to about 10.8 volts the battery will be irreprably damaged so stop it discharging long before it gets anywhere near.

Ah.... best check that as soon as we get there tonight :-(

 

[NickRobinson]

I guess you looked at the BEP monitor to get your figures. Did you look at the volts when you hooked up?

Good if EHU and VSR both not charging, probably wiring/fuse. Could you take a car charger to the boat when you go? You could give the old and new batts a tickle independently of the boat electrics.

 

[VicMallows]

Sorry to have to put it this way ...... but you will EITHER have to put in a little bit of effort to understand basic electrics and do some simple diagnosis yourself ... which we may then be able to help you with .......OR pay whatever it costs for someone to do it for you. Your symptoms as described are just too vague.

 

[lpdsn]

Following a rather rough passage last week...

Fair chance something has shaken loose. Go through and check all connections.

Use a multimeter to measure the voltage output of the charger - carefully, don't short anything. If you're getting a good voltage at this point, the charger is working correctly and your problem is between there and the batteries.

If not, charger could be buggered or there could be a power supply problem. I won't recommend that you use the multimeter on the 240V system. Best at that stage to call in someone with experience if you don't have it yourself.

 

[jamiepyoung]

Thanks for all the replies.

It turns out it was an inline 30A fuse between the charger and the battery.

The fuse had melted....

We do have a very basic understanding of the electrics and am trying to learn, including asking for advice from people who have experience of these things.

Thanks all!

 

[RichardS]

Thanks for all the replies.

It turns out it was an inline 30A fuse between the charger and the battery.

The fuse had melted....

That's a worry. What current is the charger rated at (it probably says on the front cover). If it's 30 amps or more then it sounds as if the fuse is undersized but if it's less than 30 amp then something has happened to blow the fuse unless you mean melted by an external source such as a hot exhaust or similar.

Keep a close eye on things when you replace it as 30 amp fuses blowing suggests a lot of heat potentially being developed somewhere.

Richard

 

[Russ the Diver]

[Keep a close eye on things when you replace it as 30 amp fuses blowing suggests a lot of heat potentially being developed somewhere]
+1

 

[jamiepyoung]

So having sorted out the short term problem, we have a local Electrical Engineer in now doing a survey and sorting all the main issues out.

Apparently the fuse wasn't even needed there.

There are quite a number of issues that need sorting apparently. I guess normal on an old boat that has been continually tweaked over the years.

 

[pmyatt]

You don't say the max output of your Phoenix Charger compared with the fuse size. We have a Phoenix Multi Inverter Charger 12/2500/120, which puts out up to 120 amps to the batteries; it has a 200 amp fuse.