Our future charging system?

[jim99]

New-to-us boat currently has a Yanmar 3QM30, a 35-amp Hitachi alternator with internal regulator, a diode/isolator that eats 0.7 volts and two (new) Trojan T-105s in the house bank. It takes virtually forever to put any charge on the batteries from the engine.

We plan to remove the diode and upgrade to a rebuilt 100-amp Delco alternator, a Balmar Max Charge MC-614 regulator, a Xantrex Echo Charge and add two T-105s for a total 450 a/h.

Not sure about the Echo Charge. Might opt for a voltage-sensitive relay instead. Your thoughts?

Plan to add a couple solar panels next year if I have the money. Any help appreciated.

 

[William_H]

Well your proposed system sounds very impressive and should put a lot of charge into your system.
I would however being miserly and expecting others to be likewise suggest that firstly you get rid of the diodes. You can substitute a VSR or just switches one for engine one for domestic supply. or fit a 1,2,both switch.
Fit an amp meter in to indicate how much charge you are getting into the domestic battery. This will indicate whether you need a bigger alternator, a smart charge regulator and when you are running the engine for battery charge with little actual benefit. Charge current will start high then reduce as batteries charge till result is quite small charge so not worth running the engine any more.
If you fit more batteries then you will find that you will get naturally more charge into all batteries in parallel.
Lastly the Balmar will give more charge over a shorter period of engine running. With large batteries and the Balmar you may find that the capability of the alternator becomes the current limitting point. But don't forget you may have to upgrade the belt drive to get the extra power out of the alternator.
I see the Xantrex Echo Charger as just another VSR despite fancy sales blurb but limited to 15amps charge.
An alternator to battery charger more expensive but a way to get that boost charge into you domestic battery without tampering with your alternator.
good luck olewill

 

[john_morris_uk]

Even simpler than getting rid of the diodes is to force the alternator to sense the battery voltage actually at the batteries. On some regulators you can just add a wire, and on some you need to fit a different regulator that has battery sense as an option.

Diodes without battery sense charging are a poor choice. Some people swear by VSR's, but either option will do the job.

If I understand all the details (and I haven't double checked the items you list) the rest of your choices seem very sensible and will certainly improve the system.