Battery charger connection?

[Zippysigma]

After replacing my batteries, I managed to short out one of the positive terminal leads to the engine whilst battery was switched on and engine running. (pulley chafed through insulation as I had not ensured it was routed correctly)

My battery charger CDM 230-50-12-08-2S would no longer show it's green "Tension chargeur" led. I found a fuse blown inside, so replaced that, but still no light.

When I measure the DC voltage across the output when connected to the mains, I get 12.5V, even with the battery connector switches turned off, so I wonder if it is actually charging.

What I don't know is whether the batteries would be connected to the charger, even if the battery selector switches are turned off. Can anyone help?

I guess that the obvious test would be to have checked this voltage when the battery charger was not connected to the mains, but I did not think of that until I started typing this :-(

The manual is in French, so just hoping one of you can shed some light.

Thanks.

 

[nigelmercier]

When I measure the DC voltage across the output when connected to the mains, I get 12.5V, even with the battery connector switches turned off, so I wonder if it is actually charging.
...
What I don't know is whether the batteries would be connected to the charger, even if the battery selector switches are turned off...

You need to check the connection, it could be wired either way. Best thing to do would be to isolate the charger then check the voltage, but 12.5V isn't going to charge your batteries.

 

[Billjratt]

Were you plugged into the mains (charger on) while running the engine when the short occured?
Have you moved wiring ? We have to assume it was all working before the short.

Normally I would wire the mains charger direct to the batteries if it's a multi-output unit, then it can charge regardless of the battery output switch position.

If it's a single output charger, and the switch is used to direct the charge to different banks, it obviously has to connect to the output terminal of the switch.

Is there no ammeter on board? Connecting the charger, measuring the battery voltage,then switching on the mains should produce a measured increase in the battery voltage.

Unfortunately, the cleverer these chargers are, the more difficult they are to fix and more costly to replace.

Are you sure there isn't another fuse in there that you may have missed?

 

[alan]

Battery Charger Connection

Beneteau factory wired their chargers direct to the batteries on the 311 (I used to have one!). So, the switches can be left in the off position and still charge the batteries from the charger.

Alan.

 

[VicS]

Were you plugged into the mains (charger on) while running the engine when the short occured?
Have you moved wiring ? We have to assume it was all working before the short.

Normally I would wire the mains charger direct to the batteries if it's a multi-output unit, then it can charge regardless of the battery output switch position.

If it's a single output charger, and the switch is used to direct the charge to different banks, it obviously has to connect to the output terminal of the switch.

Is there no ammeter on board? Connecting the charger, measuring the battery voltage,then switching on the mains should produce a measured increase in the battery voltage.

Unfortunately, the cleverer these chargers are, the more difficult they are to fix and more costly to replace.

Are you sure there isn't another fuse in there that you may have missed?

Its a multi output charger. I think you will find that all the CDM range are.

I assume its a 50 amp one and will therefore have 3 outputs.

There should be two fuses. One on the mains input and one on the output.

One has been replaced. Maybe the other has blown as well.

 

[Zippysigma]

Thanks for both replies.

No, the mains was not connected when the short occured.

It is a 2 battery charger and I have a separate switch for each battery rather than a single 0,1,2,both, so I guess it is directly wired.

There is no ammeter (small Beneteau).

The fuse that was blown was a pcb mounted cylinder, so I guess there may me another.

Of course the charger can only be seen when hanging by one hand upside down in the cave locker in the dark and no room for 2 hands! dont you love boats?

I guess I will need to take another look.

 

[Zippysigma]

Looks like we had an overlap of replies.

Thanks all, I will take another look for a second fuse. Now I know that they are directly wired, it will help the investigation.

So - showing my ignorance here -

If both batteries are permanantly connected, and one is run down (the domestic usually), but the engine battery is fully charged, can these chargers "boost" one, but "trickle" the other according to the voltage they sense?

 

[Zippysigma]

Battery charger woes update - advice please

Ok, Billjrat was right, there was another fuse on the pcb mains in. When I replaced this, and turned power on, there was a spark and phutt from between the transformer and the bead diodes. One of the diodes is now black and a dead short (measured on the board still).

Does anyone know if it is worth trying to change the transformer and diode or if there is likely to be more damage to other components (beyond my fault finding capabilites).

Alternatively, is there a company who can repair this type of dual output charger cost effectively?

Thanks

 

[nigelmercier]

... there was another fuse ... there was a spark and phutt ... One of the diodes is now black...

Fuses normally blow for a reason, looks like you found it. If this is one of the main rectifying diodes (relatively big) then something later on is causing the problem. If you can get hold of a schematic diagram, it might be worth trying to DIY a repair.