Split charge diodes

[waterboy]

I have been advised to install a split charge diode with a battery change-over switch.

The boat, a Beneteau 411, built in 2000 already has 2 individual battery bank isolator switches together with a master switch for the whole lot. I am no electrical expert but there already is some diodish looking bit of kit with cooling fins in the electrics area - I don't think it is the battery charger.

I understand that UK charter boats have to have split charge diodes and change-over switches fitted. Can any forumites tell me on what advantages and safety improvements I would see as a result of this modification over the existing standard system.

<hr width=100% size=1>I never make the same mistake twice. I always make new ones.

 

[TonyBrooks]

I am a bit confused.

Split charge diode makes sense, but why the battery change over switch - all that does in addition to the diodes is to allow you to switch the engine load between banks & (unless there are double pole ones I have never come across) anothe one to switch the domestic load between banks.

In my view you just need the split charging diode (at the risk of setting off another thread, I would prefer a split chareg relay unless your alternator is battery sensed) and a decent jump lead. Make sure both banks negatives are joined by "starter" cable and then if one bank fails and you do not want to physically change batteries about, apply the jump lead pos to pos.

Now the rest of your post.

If you have your two battery isolator switches, I can see no need for anything extra, but if you have the third "overall" isolator I suspect it is in the negative side of the circuits and at least one authority states this is dangerous - not sure I agree on most boats.

Now the finned thing.

If it has three wires attached and (assuming on winches, thrusters or inverters) they are the next thickest after teh starter cables there is a very good chance that it is a blocking diode. If you can trace the wires the cables one should run from the alternator positive output terminal, and the other two should run to the switched side (output) of the master switches. If they do - its a charge spliting decvice.

Tony Brooks

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[Johnnygil]

Well Thats crystal clear now

Wish I understood all of the above LOL



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[waterboy]

Thanks Tony. What you say makes sense.

<hr width=100% size=1>I never make the same mistake twice. I always make new ones.