Blue Sea Dual Battery Install

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Alternator connection

ontopofm - In answer to your PM, I did not move the alternator wire to the house battery. I left all (3) fusible link wires attached to the + battery terminal of the start battery. (as it originally was - See the Toyota EWD's below)

Per the EWD, the alternator (or generator as they call it) connects to the start battery via a fusible link (FL MAIN 2.0L -> G2). I saw no need to move this to the house battery as it is the start battery that receives the charge first.

I did however replace the heavy gauge cable from the starter to the battery with one that extended to the Blue Sea dial switch. This seems appropriate due to the high current that is used with the starter, as opposed to the charging current coming from the alternator.

With the ACR, you want the start battery to charge first. Once it reaches 13.6V, it will connect the house battery and allow it to start charging.

I cannot see a good reason why the alternator should be connected to the Blue Sea dial switch or the house battery directly. If someone else knows better (and can provide some type of documentation to support it) I am all ears...

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I concur with Mr Krietz regarding the alternator wiring.

But the whole idea of needing a separate house battery is problematic with what a truck does. Contrast with a boat that you live aboard, have things like TV's, DVD players, and microwaves. I can see the 2nd bat if the truck powers a living trailer, or has a tent on top and you plan to park for a week. I can see a separate start bat for that application. But for typical use it seems excessive. If you're worried about loss of power over an evening, just get a larger battery to handle the expected use - one designed for cyclic use. Deep cycle bats work pretty well for starting, too.

If absolute ability to start is the goal, a smallish start battery isolated with a diode might be sufficient (commonly applied in the boat world).

BAT-ISO.webp

But - who am I to say enough is enough with all my camera toys... and my boat had two 800AHr house banks and a 220AHr start bank...

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I went ahead ans installed the 120A kit. It has been fine so far. The main battery gets 14.2v charge then about 5s later the house battery get the same charge. I added the 2 mini volt meters to check/keep track each battery.

Sent from my iPhone using IH8MUD

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That's cool! What's the freeway full of blue tail lamps behind the iPad mount?

I like the idea of two meters. Makes it easy to see at a glance how far down the batteries are.

As for 120A relay vs. 150A alternator - there's no hard lines to follow. In most cases you'll never see maximum alternator output unless you really planned to use it: an 800AH battery will utilize 100% of a 150A alternator for hours; however that same alternator on a car size battery will never see much over 100A, even then only for a few minutes.
 
It's a wallpaper from the HU :)

Sent from my iPad using IH8MUD
 
ontopofm said:
I went ahead ans installed the 120A kit. It has been fine so far. The main battery gets 14.2v charge then about 5s later the house battery get the same charge. I added the 2 mini volt meters to check/keep track each battery.

Sent from my iPhone using IH8MUD
Click to expand...

Where did you get those meters? Have a part number, cost or website? Do they fit into the standard dash openings?
 
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