House batteries not charging when engine running

[Davidasailor26]

ok i found this in H410 Owner's Manual

View attachment 233765
Note page # on the left.

Others can chime in to help you.

Jim...

The alternator isn’t in the picture, so it’s a little hard to tell what’s actually charging the batteries when the engine is running. Best I can tell though is that when the engine key is on the solenoid parallels the house and start banks, so they should both have the same voltage when the engine is running. The OP doesn’t see the same voltage on both banks, so either:

• The solenoid failed
• The house battery select switch is set to off
• This boat isn’t wired as the diagram shows
• I’m misinterpreting the diagram

 

[JamesG161]

David, you are correct.

My guess is his ignition key to operate the solenoid does not work, thus engine alternator is only charging the Start Battery.

It will never charge the House Batteriess. When had similar issues, i carry a pair of jumper cables to connect
Start Batts to house batteries to charge them from the Alternator.

Good luck
Jim...

 

[Davidasailor26]

David, you are correct.

My guess is his ignition key to operate the solenoid does not work, thus engine alternator is only charging the Start Battery.

It will never charge the House Batteriess. When had similar issues, i carry a pair of jumper cables to connect
Start Batts to house batteries to charge them from the Alternator.

View attachment 233776
Good luck
Jim...

I guess it could be the key too, but in many boats the key also controls other things like the alternator field, electric fuel pump, and oil pressure alarm. If the H410 requires the key for any of those things it would be apparent it’s not working, whereas the solenoid could fail more silently.

 

[JamesG161]

This is the ACR , 1998 version, which is located behind the Battery Selector Switches. @Davidasailor26

I chatted with the Hunter Electrician who wired my boat to understand the design.
Note the Heat Sinks needed to dump the Amps flow Heat.

I asked why the unused connection.

Ans: Different size boats and alternators

My ACR never worked, since Grey Solenoid failed often.

Jim...

 

[Davidasailor26]

This is the ACR , 1998 version, which is located behind the Battery Selector Switches. @Davidasailor26

View attachment 233811

I chatted with the Hunter Electrician who wired my boat to understand the design.
Note the Heat Sinks needed to dump the Amps flow Heat.

I asked why the unused connection.

Ans: Different size boats and alternators

My ACR never worked, since Grey Solenoid failed often.

Jim...

That looks like an old style diode based isolator. The heat sinks are needed because the diodes cause a big voltage drop, and in the process dissipate lots of energy as heat. Modern FET and relay based ACR’s, or transformer based DC-DC converters, are relatively efficient. They also don’t introduce the voltage drop issues that can lead to improper battery charging.

 

[Stu Jackson]

My ACR never worked, since Grey Solenoid failed often

Jim, that appears to be a battery isolator and not a combiner. The difference? Isolators keep one battery from backfeeding the other, while combiners use relays to connect battery banks when charge sources are present and disconnect them completely when charge voltage drops.

Yandina has been making combiners for decades. I have one from 1998, still works great. They also have A NEW NAME:

Combiners

SmartShore Marine

smartshoremarine.com

 

[Don S/V ILLusion]

Definitely an isolator with an inherent 0.7volt voltage drop which causes constant under-charge.