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.

 

[Benny17441]

Check all batteries individually with an inexpensive load tester and weed out any weak ones.

 

[marcham]

I'm seeking out simpler solutions first so I'm going to make sure I understand how the charge relay system works from the alternator. I'm relatively certain I need new batteries either way, but to someone's point earlier, it seems to me that when the engine is on the voltage should still be going up over 13 volts.

The reason I suspect the batteries have been drawn down numerous times is because while I was in the long process of buying her, the selector switches were left in all sorts of crazy positions and combinations without folks seeming to know how to work them. From my reading in the manual, the inverter draw selector acts like a 1/2/Both switch when the inverter remote switch is off. So leaving it in the off position while on shore power means they are getting no charge. I found the switches that way many times upon returning to the boat.

Check if you're getting 11-12 V at the Relay (the one beside the battery isolator) when the ignition is ON. Then check again once the engine is running. Do you have the battery isolator + relay setup? Boats were wired this way so that with an inverter-charger charging the house batt, the start batt would get a charge (through the isolator). Then with the engine running, the Relay (aka battery combiner) would link both battery banks with the ignition ON. Need to understand the system first before throwing money at it.....

 

[Windpilot]

I have a 410, had that same problem. Its the battery solenoid if only your start battery is charging. Its behind the panel underneath your navigation desk where the main breaker for the anchor windlass is. Cheap easy fix. The solenoid is not connecting the house battery once its started and running.

 

[Benny17441]

If your shore power charger is putting out 13+ volts and the batteries are only charging to 12.4V then one or more batteries are very weak or likely bad. A healthy battery bank will sustain 12.70V at rest and will gradually decline in a reasonable way after subjected to a load. It is best to conduct all other system diagnostics after starting with a healthy battery bank.