Dual battery setup with isolator

Darkrider_LS

Original poster
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Jan 25, 2013
9,332
Ok after a fairly informative discussion with Djthumper in the whore thread it is time to start this.

The planned setup is this:

Dual battery isolator:
http://www.westmountainradio.com/product_info.php?products_id=iso_pwr

Upgrading from standard lead acid battery under hood to an optima style battery.
Sla agm battery in the back such as this one.
http://www.canadiantire.ca/AST/brow...+22NF+SLA+Battery.jsp?locale=en&stop_mobi=yes

Now if I have my calculations right I can safely run a 300w inverter off of the isolator that Djthumper linked me to. Which is more then sufficient for my needs which is to run a laptop or dvd player from it. Anything im missing here?
 

Darkrider_LS

Original poster
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Jan 25, 2013
9,332
Edited first post to include link for isolator
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
Ok I did miss something....the isopower unit will not allow me to run an inverter to run a dvd player when the key is off...however it will allow me to use said inverter to charge up my laptop while driving. Which works great if I eventually start running a laptop as a gps like a lot of expedition guys do. Now that I know this. Can I safely run an inverter directly from the sla battery since when the key is off it is basically an isolated "house" battery?
 

djthumper

Administrator
Nov 20, 2011
14,950
North Las Vegas
If the DVD is part of the vehicle no it will not. The Car side is the car battery. The Battery side is the aux battery. Out the the supplied power output. When you are driving everything is powered by the vehicle including the charging of the battery if it needs. Once you turn the key off the aux battery will supply the power to your inverter or anything you have plugged into the out port. So if the DVD power is on the output port it will work with the key turned off.
 

Darkrider_LS

Original poster
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Jan 25, 2013
9,332
djthumper said:
If the DVD is part of the vehicle no it will not. The Car side is the car battery. The Battery side is the aux battery. Out the the supplied power output. When you are driving everything is powered by the vehicle including the charging of the battery if it needs. Once you turn the key off the aux battery will supply the power to your inverter or anything you have plugged into the out port. So if the DVD power is on the output port it will work with the key turned off.

When I first read this I was like huh? Then I reread the instructions for the iso power unit and it made sense then.
 

DJones

Member
Jan 21, 2012
701
St. Petersburg, Florida
I've thought about AGM batteries in the past but decided that the shorter warranty was not worth the extra cost. I'd prefer to go with the battery with the longest warranty.
 

bobdec

Member
Apr 19, 2013
233
Can tell you what we do in marine setups, and also used in RV setups. First your starting battery could be whatever you require for the vehicle. But I would suggest a Deep Cycle battery for the second or what is called a 'House Battery" The house battery will be charged by the isolator when engine is running. Run the power inverter off the house battery directly so it always has power, iregardless of the ignition status. Use a high current (marine or RV) 12V switch to shut off power from the battery when it's not needed. But keep the isolator always connected to house battery to keep it charged. DVD and/or laptop is a relativly low load lets say 150 watts top, about so the inverter will be drawing 15 amps from the house battery with laptop and DVD on. A 150 amp hour deep cycle battery will last a few hours w/o engine on. Now if you are using a large display w/the DVD them it's different. Im my conversion van I found when I hooked an inverter to my starting battery running a Tivo (DVR) the darn inverter cut off whenever I started the engine at rest stops because the starter battery voltage dips below 10 volts (internal inverter cutoff) when cranking. Had to re-boot at every rest stop, or keep engine on. With inverter on an isolated deep cycle this will never occur. As in any application, if you deplete the house battery it could take a few hours of running engine to get it toped off. You also have the option to install a dual battery switch, so you can use the house battery to start the engine as a backup in case starting battery fails. But with a rear mounted house battery that requires custom 0-00 gauge wiring. As is you will only need a 50 amp (fused) line from isolator to house battery if you isolator is 40 amp..
 
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Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
bobdec said:
Can tell you what we do in marine setups, and also used in RV setups. First your starting battery could be whatever you require for the vehicle. But I would suggest a Deep Cycle battery for the second or what is called a 'House Battery" The house battery will be charged by the isolator when engine is running. Run the power inverter off the house battery directly so it always has power, iregardless of the ignition status. Use a high current (marine or RV) 12V switch to shut off power from the battery when it's not needed. But keep the isolator always connected to house battery to keep it charged. DVD and/or laptop is a relativly low load lets say 150 watts top, about so the inverter will be drawing 15 amps from the house battery with laptop and DVD on. A 150 amp hour deep cycle battery will last a few hours w/o engine on. Now if you are using a large display w/the DVD them it's different. Im my conversion van I found when I hooked an inverter to my starting battery running a Tivo (DVR) the darn inverter cut off whenever I started the engine at rest stops because the starter battery voltage dips below 10 volts (internal inverter cutoff) when cranking. Had to re-boot at every rest stop, or keep engine on. With inverter on an isolated deep cycle this will never occur. As in any application, if you deplete the house battery it could take a few hours of running engine to get it toped off. You also have the option to install a dual battery switch, so you can use the house battery to start the engine as a backup in case starting battery fails. But with a rear mounted house battery that requires custom 0-00 gauge wiring. As is you will only need a 50 amp (fused) line from isolator to house battery if you isolator is 40 amp..

Thanks for the great info! Between this and what DJthumper has provided for info i have a pretty good grasp of how to go about this! :wootwoot:
 

djthumper

Administrator
Nov 20, 2011
14,950
North Las Vegas
Darkrider_LS said:
Thanks for the great info! Between this and what DJthumper has provided for info i have a pretty good grasp of how to go about this! :wootwoot:

There was a little bit more of a discussion before this was posted here...
 

Playsinsnow

Member
Nov 17, 2012
9,727
There are a few build threads on ORTB and the OS that show different mounting/setups others have used. Having a power switch and some sort of meter to keep an eye on is nice. Trailz started a thread on dual batteries under the hood a while back.
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
djthumper said:
There was a little bit more of a discussion before this was posted here...

This is true, when I get back to the computer I will see if I can find all the posts on it from the whore thread and quote them here.

Playsinsnow said:
There are a few build threads on ORTB and the OS that show different mounting/setups others have used. Having a power switch and some sort of meter to keep an eye on is nice. Trailz started a thread on dual batteries under the hood a while back.

Hmmmm looks like I will need to go all searchfu on there when I get home in the morning.
 

Playsinsnow

Member
Nov 17, 2012
9,727
trying to find a few for ya now. See what I can find after my "break" lol :bonk:
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
Playsinsnow said:
trying to find a few for ya now. See what I can find after my "break" lol :bonk:

Thanks in advance
 

djthumper

Administrator
Nov 20, 2011
14,950
North Las Vegas
Playsinsnow said:
There are a few build threads on ORTB and the OS that show different mounting/setups others have used. Having a power switch and some sort of meter to keep an eye on is nice. Trailz started a thread on dual batteries under the hood a while back.

on ORTB I believe there are 2 or 3 of them that have an aux battery setup. You can get something like this to keep an eye on the voltage and a few other things as well. DC Inline Watt Meter and Power Analyzer, Powerpole Ends [WattMeter-PP] - $59.99
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
djthumper said:
on ORTB I believe there are 2 or 3 of them that have an aux battery setup. You can get something like this to keep an eye on the voltage and a few other things as well. DC Inline Watt Meter and Power Analyzer, Powerpole Ends [WattMeter-PP] - $59.99

If Im understanding that right it would plug in between the aux battery and the isolator correct?

The thought I had on monitoring the aux battery was a voltage gauge in a pillar pod...if im understanding things right connecting the imput wire of the gauge to the positive post of the aux battery and wiring it into the truck as normal would allow me to read the aux battery status as I would the voltage gauge in the trucks cluster correct?
 

Playsinsnow

Member
Nov 17, 2012
9,727
Roadie, Philberto, and the man James D have all included dual batteries in their builds

offroadTB.com - View topic - The Roadie's Build - 2004 GMC Envoy

offroadTB.com - View topic - Philberto's Build - 2006 Chevrolet Trailblazer

offroadTB.com - View topic - JamesDowning's Build - 2005 Chevrolet Trailblazer


Here is a mod from ORTB re: National Luna Dual Battery Isolator
offroadTB.com - View topic - MOD: National Luna Dual Battery Isolator


And another setup with visual
Dual Battery Setup Advice - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum



Seems like the mod is custom to the specific needs/wants... I like the idea of keeping it out of the cab, or at least not exposed.

trailz thread
http://gmtnation.com/f24/dual-batteries-underhood-i6-3256/



Keep us updated!
 

djthumper

Administrator
Nov 20, 2011
14,950
North Las Vegas
Darkrider_LS said:
If Im understanding that right it would plug in between the aux battery and the isolator correct?

The thought I had on monitoring the aux battery was a voltage gauge in a pillar pod...if im understanding things right connecting the imput wire of the gauge to the positive post of the aux battery and wiring it into the truck as normal would allow me to read the aux battery status as I would the voltage gauge in the trucks cluster correct?

Yes, there are several different ways to do it. As there are several different meters on that site as well.
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
djthumper said:
Yes, there are several different ways to do it. As there are several different meters on that site as well.

Sweet...back to the site I go!
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
Playsinsnow said:
Roadie, Philberto, and the man James D have all included dual batteries in their builds

offroadTB.com - View topic - The Roadie's Build - 2004 GMC Envoy

offroadTB.com - View topic - Philberto's Build - 2006 Chevrolet Trailblazer

offroadTB.com - View topic - JamesDowning's Build - 2005 Chevrolet Trailblazer


Here is a mod from ORTB re: National Luna Dual Battery Isolator
offroadTB.com - View topic - MOD: National Luna Dual Battery Isolator


And another setup with visual
Dual Battery Setup Advice - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum



Seems like the mod is custom to the specific needs/wants... I like the idea of keeping it out of the cab, or at least not exposed.

trailz thread
http://gmtnation.com/f24/dual-batteries-underhood-i6-3256/



Keep us updated!

Thanks for the info plays! Found james ds setup on the forum via the build thread and that looks like the closest to what I have in my mind! It has the two different battery types like I mentioned above, I may end up building a sub box style enclosure and mounting it directly behind the passenger side rear seat back. Either that or revisit a cargo management idea I had that bolted in using the oe tie down points in the rear with a solid cargo cover which would give me a lil more room to lay things out and gain a locked trunk like space at the same time.
 

meerschm

Member
Aug 26, 2012
1,079
a little about battery charging:

Battery Testing, Maintenance And Myths

you want to think about the various equipment combinations.

a half volt drop can mean quite a bit of charge not on the battery.

our generators are all self-regulated, meaning they think the battery is right at the output, electrically.

will you want to charge on the road? or charge at home, or both?

something like this
http://www.powerstream.com/battery-isolator.htm

will charge your aux battery to a higher level, and give you the isolation you want.

i would stay away from any solution that makes you put a device between your generator/alternator and starting battery. a few of the diagrams referenced above show an isolator between the alternator and starting battery. this will reduce the charge you can put on the battery. from your location, I am betting you at some point will want a fully charged battery available when it is on the chilly side.
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
meerschm said:
a little about battery charging:

Battery Testing, Maintenance And Myths

you want to think about the various equipment combinations.

a half volt drop can mean quite a bit of charge not on the battery.

our generators are all self-regulated, meaning they think the battery is right at the output, electrically.

will you want to charge on the road? or charge at home, or both?

something like this
12V 150 amp DC battery isolator and split charge relay for RV, car, and truck applications

will charge your aux battery to a higher level, and give you the isolation you want.

i would stay away from any solution that makes you put a device between your generator/alternator and starting battery. a few of the diagrams referenced above show an isolator between the alternator and starting battery. this will reduce the charge you can put on the battery. from your location, I am betting you at some point will want a fully charged battery available when it is on the chilly side.

Nice bit of info to read through there! Thanks! To answer your question i would prefer to have the aux battery charging while the truck is being driven. The Iso power unit above does the same thing as the one you listed but also gives me an output for an inverter or what ever exterior device i wish to use. If i wire it the same as DJthumper has his i will be pulling the Car side imput from the power point under the seat that powers the rear fuse box which fits with your suggestion above. However i will def look at that isolator you listed for my S10 Blazer since it too will be getting dual batteries but for different reasons.
 

meerschm

Member
Aug 26, 2012
1,079
my $.02 worth is that the quarter volt drop will prevent the aux battery from fully charging,

probably not huge, since the main battery will fully charge.

congrats on your ambition and good luck on the project!
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
meerschm said:
my $.02 worth is that the quarter volt drop will prevent the aux battery from fully charging,

probably not huge, since the main battery will fully charge.

congrats on your ambition and good luck on the project!

Thanks!
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
Bumping this up so I can reread it better on the computer....going to start working on a dual battery system in the van within the next couple weeks.
 
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HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Darkrider_LS said:
Bumping this up so I can reread it better on the computer....going to start working on a dual battery system in the van within the next couple weeks.
How does bumping it make it easier to read...
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
HARDTRAILZ said:
How does bumping it make it easier to read...
Because it makes it easier to read the information provided by the links in the thread...my phone doesn't always agree with clicking on links via tapawhore
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Bumping changes the links how?
 

Darkrider_LS

Original poster
Member
Jan 25, 2013
9,332
HARDTRAILZ said:
Bumping changes the links how?
It makes the thread easy to find on the computer later, thus making it easier to read said links on said computer.
 

6716

Member
Jul 24, 2012
821
So in the Roadie's build, he talks about taking power from the post in the fuse box in the back seat.

Where would you ground that? I guess there's a ground on the B pillar Electrical Ground locations | GMTNation but how the heck do I get at that, like under the carpeting and inside the trim? Is there somewhere else to ground?
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
So in the Roadie's build, he talks about taking power from the post in the fuse box in the back seat.

Where would you ground that? I guess there's a ground on the B pillar Electrical Ground locations | GMTNation but how the heck do I get at that, like under the carpeting and inside the trim? Is there somewhere else to ground?

For the B pillar grounds, it's behind the lower of the 2 trim panels. I don't have a pic, but it's at about the same height as the lower door hinge. There's a bolt, holding a ring terminal with one of the factory ground wires to it. I used these on either side for grounding my scuff plate LEDs that I connected to the dome lights. :twocents:
 

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