Battery alarm

[marioxp]

When I start my B36 (2003) after few seconds battery alarm is triggered (sound and light) and it will not stop for long time (5-15min).

I have checked alternator, and it is charging batteries with a considerable amount of current. I have checked engine battery, before start voltage is about 13.25V when I start glowing engine voltage drops, but when motor start running and alternator start product current voltage rise to about 14V, despite that battery alarm is triggered!
I did not notice any other problem in the engine work, I only noticed that around the time this problem first time occurred that gauge for showing status of battery charge level and tank level gauge has stooped work.

I was checking the contacts at the alarm light i and they seem good to me.

I think the alarm circuit don't gets accurate voltage data. I do not know why battery charge level and tank level gauge doesn't work, and whether these two problems are related?

[Jake]

Check and verify the connections for the alarm.  It could be a loose or corroded connection, especially because you have other electrical items that have stopped working.

Are you reading the battery voltage at the engine panel or from a meter in another location?

Jake

[Salty]

if the alarm is coming from the engine alarm system at the bottom of the engine control panel, its probably the charging alarm that you are hearing. Try increasing the engine speed by just a few rpm, it might be that the engine idle speed is just a touch too low and needs slight adjustment. Alternatively just  give the engine a few more revs at start up for ten or fifteen seconds and then put the control lever back to idle.

[marioxp]

Are you reading the battery voltage at the engine panel or from a meter in another location?

Jake

Jake, I know what you mean!

I regret not making that measurement already done. I think, I could find that voltage at alarm probe is to low.

But first i have to find alarm probe for voltage (place where alarm measure voltage) Does anyone know where is it place?

[marioxp]

if the alarm is coming from the engine alarm system at the bottom of the engine control panel, its probably the charging alarm that you are hearing.

Yes this engine alarm

Try increasing the engine speed by just a few rpm, it might be that the engine idle speed is just a touch too low and needs slight adjustment. Alternatively just  give the engine a few more revs at start up for ten or fifteen seconds and then put the control lever back to idle.

This doesn't help, I had tried.
The alternator works, it's not a problem, I measured.
Problem is with measuring voltage by alarm, or with the alarm itself.

[IslandAlchemy]

Check that you're getting charge to both battery banks.  It could be your diode splitter that's failed.

[IslandAlchemy]

Ignore what I just said, that was a daft comment.

[artemis]

Had the same issue its was the Logic Control Unit for Alarm Module. The bulbs let in water and corroded casing the alarm to come on all the time ended up getting new control unit not cheap...

Rgds
Mike
Artemis

[Jake]

Marioxp,

You may have to remove the engine panel to get at the 12v source to the alarm.  I haven't had my panel out yet, but I plan to (just to replace some of the bulbs with LEDs).  Hopefully, you just have a bad connection on the back of the panel.  I've seen some that aren't installed well and allow water to seep around the edges.  I prefer to have a cover over mine so it at least keeps the sun off of it.  The plastic gauges are showing some dulling from the sun.

Jake

[ICENI]

I had a similar problem in my 2002 Bavaria 32 last year.

After checking measurements at the alternator output and also the positive and negative terminals at the batteries, I removed the engine control panel and cleaned all the connections.   After that I sprayed them with contact cleaner.   

The problem has not re occurred.

It must be noted that the gauges on my boat were unaffected so you might have corrosion elsewhere.

[Salty]

Had the same issue its was the Logic Control Unit for Alarm Module. The bulbs let in water and corroded casing the alarm to come on all the time ended up getting new control unit not cheap...

Replaced mine with a new (Old stock) unit purchased from Coastal Rides in Dover. This was quite a while back and I don’t  remember the exact price, around £100 give or take. They often have new (Old Stock) goodies which make them a useful supplier of odds and bits for older boats. Having a clear out in the garage today, and found what I think were two used but good bulbs which were consigned to the trash can, Its not been emptied yet, so I’ll fish them back out and test them. If they do still work I’ll let you know, yours for the cost of postage.
Ok, the bulbs have been retrieved, checking them with an AVO meter shows a circuit, but there is some external corrosion on the brass part which could do with cleaning off. An initial check on one did not confirm a circuit until I found a cleanish bit of brass to place the AVO probe onto, then it confirmed the bulb was fine. if anybody wants them I’ll bubble wrap and place them in an envelope for the cost of postage.

[marioxp]

Thx everybody

Engine control panel and above panel with raymarine instruments are sealed with sponge. Now this sponge is old and it's falling apart.

I'm not sure that sponge is appropriate sealing material for this panels, because this panels are exposed to water, rain... and they cover electronic devices.

I have to replace this disgusting sponge but what will be replacement material.

Silicon no, because I want to be able to approach inside of panel and silicone bonding will be permanent solution.

[Yngmar]

New sponge! Which is actually called foam gasket tape: https://www.google.com/search?q=foam+gasket+tape&tbm=isch

[JEN-et-ROSS]

We replaced ours with a gasket cut from a sheet of closed cell foam PE packaging. It was about 5mm thick and quite compressible. Cheap but very effective...

[Salty]

In the past I have used offcuts of left over vinyl floor covering, it worked a treat, it was compressible, and would otherwise have just been thrown away.