R-21 Battery Charging

[Kamalani]

ANDREW - hey, I have a question as to how the battery charger works with the charging relay on the R-21 (2009). I am looking at the schematic pg 1, and it appears that the charger is wired directly to the #1 Eng start batt only. However, on the pos. side, Batt 1 is wired to Batt.2 through the charging relay by way of the "Batt 2 buss". So, with this arrangement, will the charger then charge both batteries depending on which one reads the lowest voltage? Does it only charge one batt at a time, or can both be receiving a charge simultaneously? For that matter, does the alternator work the same way? ie. will both batts be charged from the alternator as well?
Thanks, Alex. "Kamalani"

 

[Andrew Custis]

Hello Alex,

The first question I would have for you is this. What kind of battery charger do you have on board?

We install this automatic charging relay that acts as a relay to open the circuit to both batteries and charge with the charger and the alternator. It also acts as a battery isolator that when it reaches 10.8 volts it will not tie the batteries together if it senses a charge. In this case, you have to install this relay to allow the alternator to charge both batteries off of a single wire output. You can go to this link and learn more about this relay if you like.

http://bluesea.com/category/2/productline/overview/387

 

[Sterellie]

Andrew,

2009 21Ec. In the stern there is a 3 prong plug. Is this for 110v shore power and battery charging?

 

[Kamalani]

Sterellie - I hope Andrew will correct this if I'm off base, but as far as I know, the 3 prong (15A) inlet in the stern is only connected to the battery charger. There really is no shore power circuitry onboard as far as 115 v outlets etc.

Andrew - thanks for the follow-up. Our charger is a ProMariner ProTech probably 1210i (10 amp). The reason for all of the questions, is that I want to install a battery monitor, and at least one AC outlet from an inverter. I'm just trying to figure out how to wire all of this into the boat and be able to read the condition of each battery, as well as to have control over which battery(s) will feed the inverter. I am hoping to keep the #1 start batt. out of the loop. My charge relay says "automotive" and I don't think it's from Blue Seas. Would it protect the start batt. if an inverter were connected to the house bank? I refuse to snip one wire until I have a much better understanding of this project.

Thanks! Alex.

 

[Kamalani]

WAIT! - after reviewing the link you provided to Blue Seas, I believe that we do have the same relay installed. Thanks, Alex.

 

[Andrew Custis]

You are correct about the plug in the stern. All this does is provide a power source to the battery charger.

As for your Inverter installation, give me a call and I can give you some helpful hints on how to install this. Let me know which inverter you plan on using as well and I can get some stuff together for you. Thanks!

 

[Kamalani]

THANKS, ANDREW - now that's prompt customer service! It must have taken all of 3 min. for you to fire that reply back. I'll call you as soon as I get my ducks... well you know.
Alex.