Bizzare Outboard Electrical Problem

[oldgrowth]

Pete – I have the same Blue Sea ACR as you but my switch is either off or on. With the switch off the ACR does the combining for charging purposes and when I want to manually combine the batteries I turn the switch to on.

I have noticed that sometimes the charging voltage gets in the 17 volt range and the ACR indicates an overvoltage when the engine is first started. When this happens, I turn my switch to the on position so the batteries are combined. The charging voltage drops back into the 13 to 14 volt range and after a couple of minutes I turn the switch back off and everything seems normal.
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Dave

[Falco]

Adeline: So what did Blue Sea tell you? I looked at the wiring diagrams for both components off the Bliue Sea web site. Looking at your photo it's tough to draw any conclusions as the battery switch is connection-side down and other connections to the batteries are omitted (like the jumper from Terminal 1 to Terminal B for sensing voltage in your house battery bank and the line from Terminal 3 to your negative bus - the ACR has to be grounded).

As far as combining the batteries for emergency starting, check with Blue Sea but this can (must?) be done with a switch to Terminal 2 of the ACR (and not via the battery switch). See the section "To connect a manual override switch" on page 2 of the ACR instructions.

A note to another posters. I don't think an ACR ever combines batteries in parallel for electric supply - this has to be done manually if at all. The ACR charges only one battery at a time, depending on their charge state. The only exception is when a switch is thrown on the ACR itself (if so equipped) for manual combining - see above.

[oldgrowth]

[thataway]

The ACR combines batteries in parallel at 13.7 volts (default) and disconnects at 12.7 volts.
That is all it is--it does not select which battery to charge, it just combines the batteries --this called a "combiner". The features of the ACR is that the combine and cut out voltage are adjustable (within a narrow limit) and it uses low current for the relay to combine.

Normally when you don't have a charger going, the batteries will be isolated, unless you put on the optional switch, which will allow the batteries to combine. The relay is rated at 60 amps (basically the contacts may be damaged if you exceed this) so you don't want to combine this way to start an engine--use a switch to combine for starting if the start battery is low.

[Falco]

Here's what Blue Sea has to say: