Dual Battery setup with Voltage-Sensing Relay

[esh]

This might be useful enough on its own that I pulled it from my build thread.

I am using a BEP Marine VSR (voltage-sensing relay). Let me show you a comparison with another brand that led me to this choice...

BEP Marine 300A VSR
- 300A continuous, 1250A instantaneous rating
- marine-grade, sealed
- $135 on Ebay, + 2nd voltage gauge (~$30) or aus dual digital volt gauge (~$65) = up to $200
- on (combine batteries), auto (voltage sense mode), off (isolate batteries)
- auto mode- isolates Aux battery until Main reaches 13.7V
- control switch on unit housing with wiring/plug for remote switching (emergency parallel override)

Brand "NL"
- 85A continuous
- rubber covers, automotive sealing
- $375
- not quite so similar or simple operation, but has low-voltage protection system (see below)
- auto mode- (bear with...) if the Main goes above 13.1V, a 5m timer starts.. after 5m, Aux batter can be charged.. 12.7V cutout automatically disconnects both batteries but can be overridden.. on engine shut-down, both batteries stay connected until 12.7V level is reached
- remote monitor/controller has cutout override/jump-start (combine) mode


I used Marco's (Rover67) writeup on Rising Sun club forums as a guide. It is nearly identical to my connections. I think the only minor differences are my starter is connected directly to the Main and the alternator is on the VSR +battery post.

My cable runs, battery locations, and VSR location were decided upon by how difficult it would be to modify existing wiring and make new runs. The 1HZ starter is on the driver's side so my Main went there (shortest distance). Likewise the factory wiring came out on the passenger, so instead of extending the "bundle" I just turn it all aft and connected to the +battery post of the VSR. The only added cables were a 1/0 cable from Main to +battery, and another 1/0 from Aux (+) to the VSR's "load" post.


VSR locating. Used a simple piece of steel channel with one side cut off for an L bracket(scrap on hand), also made two small spacers to push the air filter housing out about 3/4" All used existing captured nuts and Toyota fasteners.

mount bracket painted with Duplicolor Wheel Paint (Graphite). i am obsessed with that paint, it is great stuff. also rounded all the edges and corners near cabling

wiring.. 3 connections. had to hog out the oem connector a little. you can see the marine sealing of the VSR's housing

Main battery- G34 (32? forget now) Sears DieHard Platinum on stainlesstrays.com tray, my cables and military top posts from WranglerNW Power Products in Portland. oh and my fugly battery clamp made from scrap

Aux- was my main, a Blue Top Optima (same as yellow with extra top posts.. handy). Connections are VSR, wayne tangen's headlight harness, stereo amps, winch, accessory fuse block in passenger kick panel. Need to reroute the Main VSR cable more stealthily. VSR in background.

VSR installed. looped cable is the remote switch cable/connectors

dual gauge showing Auto (voltage-sensing) mode readouts. top is Main, bottom is Aux

readout with VSR set to Off (isolate) mode

did run into a minor design flaw. the coil spring arm hits my spaced air housing mount now. have been meaning to swap to struts and design around it. note: fender panel has my last 3FE compression numbers behind the engine swap.. Cyl 6 was 165 before the engine was ejected. (cylinder #6 now has much, much greater compression )

another interference shot

 

[wheelin62]

I am using the BlueSea ACR with a dual circuit marine battery switch. The switch is primarily used for selecting starting battery (usally left on the main battery), and self jumping. The ACR does the rest.
The only thing that I learned recently was this ACR won't charge the backup if the volts drop to low. After using my rear winch alot on a past trip I noticed the ACR wasn't charging that battery. Not until I switched the battery switch to both did the ACR start functioning again. Just something I will have to keep a mental note on next time.
Other than that I have had no problems with this setup.

 

[Granite Grinder]

Nice install esh, can't wait to start mine. Haven't decided on a system yet, but I'm liking your write up. Did you hook up a switch inside to join the two batteries? Is this an option or do you need to rotate the switch under the hood for manual override?

 

[esh]

You just need to wire that plug to a switch in-cab of your choice. The remote switch allows for emergency parallel (connected) battery operation.

There is a good Installation doc on the VSR page- 300Amp Voltage Sensitive Relay (VSR)

 

[Benjaman]

Looks like I'm not the only one to put that spot to good use.

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under hood-1 by MyWeirdStuff, on Flickr[/IMG]

 

[Spook50]

Looks similar to what I was planning on doing for a dual batt setup, only my plan was to go with a National Luna set and a G34 (or 31, whichever the bigger one is) blue top so I can take advantage of the extra posts. Planning to run stereo amp, extra lighting @ accessories (winch included, but will be augmented by the main) off the secondary, and primary vehicle systems off the main. My intention is to have them isolated until the primary reaches the "full" voltage, but be able to parallel the batteries for winching, jumping, and self-start assist when needed.

Interesting that this seems so much more capable than the NL setup. I might have to rethink my dual batt plans.

 

[Kynot62]

Spook

The 31 is the larger Optima. One word of caution, they weigh around 20 lbs (each) more than the 34's. I kept things simple in my diesel. All I have is a Blue Seas on/off switch that will run each battery individually or combined. Most of the time combined.

Jump start cables hard wired to left side battery so it can be isolated for jumping others.

Winch is wired to right hand battery so it can be isolated.

I like things simple.

Tony

 

[Spook50]

Spook

The 31 is the larger Optima. One word of caution, they weigh around 20 lbs (each) more than the 34's. I kept things simple in my diesel. All I have is a Blue Seas on/off switch that will run each battery individually or combined. Most of the time combined.

Jump start cables hard wired to left side battery so it can be isolated for jumping others.

Winch is wired to right hand battery so it can be isolated.

I like things simple.

Tony

Yeah the 31 is the one I've already got on the right side. It's a yellow top, so I'll keep it over there, and put a blue top G31 on the left side for accessories, jumping and winching. What's interesting is that the instructions for the VSR say that it'll aotumatically combine batteries when there's a high load (such as [STRIKE]maps[/STRIKE] winching) on it. The VSR, while not as simple as a manual switch in the engine bay, is alot simpler that some of the other methods I had investigated.

Only hangup I see now is if I wanted a second voltmeter (got a spot on my A-pillar that I could put it too) I'd have to wire it to a relay that's powered by the ignition circuit so that it would shut off when the truck is off.

 

[Kynot62]

In my original set up in the 62, I connected one voltmeter to both batteries through a 3 way momentary switch. Pushing the switch left would read the left batt push to the right would read the right one. Simple and doesn't need to be turned off.

Tony

 

[Spook50]

In my original set up in the 62, I connected one voltmeter to both batteries through a 3 way momentary switch. Pushing the switch left would read the left batt push to the right would read the right one. Simple and doesn't need to be turned off.

Tony

I had thought of that, but with the factory voltmeter already being connected to the main battery and constantly showing that voltage, I want to wire up one that's dedicated to my secondary battery, and since I've already got a 2 1/16" gauge pod on my A pillar for the tranny temp gauge (which will be gone when the H55 goes in), I can utilize the space for a voltmeter

 

[esh]

Here's my gauge mfr web site- RGB Electronics (Australia)

Ebay Aus has it listed as "dual battery monitor"

 

[ntsqd]

My battery charge/combine plan is very similar to Kynot's, though with one addition. I have one of the single sensing BEP VSR's that I will connect to the terminals on the same battery bank switch. That way I can leave the switch normally set on "1" and still have the 'house' battery get charged. All of my added electrical demands will eventually be put on the house battery.
My thinking on the voltmeter was also the same, though I hadn't yet worked out any of those details.

 

[esh]

Just a heads up.. you can see from the pics that the thing installed was a Battery Switch (not a VSR). I swapped to a VSR after the installation was all setup and got the gauge pics from that. I noticed my install above was with the switch after I was done and had a 2nd unit that actually was a VSR (for another truck) on hand.

Looking around for prices on another VSR, I haven't found anything for under $200. Ebay now only has the 100 or 125A units (without the housing switch on them). My other usual sources, Froogle and Amazon, don't carry the 300A units either. West Marine sells them for $215 and it is order-only.

So currently the price/availability seems to have dried up with the end of recreation season. So my revised price is $250-$285 depending on how you do a gauge.

The 125A versions would work fine and still be rated for more amps than "most brands". And they are significantly cheaper.. so options would be:

125A - $85
300A - $200

Ultra value setup would be a $20 2nd gauge and the 125A model and you'd be just a hair over $100 for a solid dual battery setup. Maybe $30 in cable ends and stuff if you had a large crimper.

..but i'll keep watching ebay for deals

 

[ntsqd]

My operating idea is that the VSR need only be able to carry the alternator's max output current. Anything higher sees the switch get changed. In that method the 100A-125A VSR's are well placed. If you want the VSR to carry starting, jump-starting, or winching loads then it isn't very well placed.

 

[Spook50]

My operating idea is that the VSR need only be able to carry the alternator's max output current. Anything higher sees the switch get changed. In that method the 100A-125A VSR's are well placed. If you want the VSR to carry starting, jump-starting, or winching loads then it isn't very well placed.

I like overkill, so I'd probably still go with the 300A unit. Plus if this alternator tanks for good (beyond a voltage regulator failure), I'll install a Mean Green unit, which are 140A for the 3FE ones.