Thought I would share some pictures and my procedures for a dual battery install. This is model specific but can cross over to many other makes and models. I have been on the injured list for over a year now and still disabled for the next season or two. This project would normally be a few days at the most. I did it in 15 - 30 minute stints so it took over a month with help from friends with battery lifting.
I'm getting to a point in my life to do some more mellow stuff like off the grid in my truck with some luxury. I have experience riding motorcycles and simple camping. I have a heavy background in my younger years in fabrication, temporary power, and generator field.
First off I think we all can agree that solar and lithium technology is advancing at an alarming rate. As with any project there are 100's if not 1000's of different ways to approach and achieve a project such as mine.
With that in mind I decided to go simple with room to grow in the future. For now I will be doing a basic ACR relay system with a pair of Group 78 AGM batteries fitted to factory trays under the hood.
The heart of the system will be my Mechman 250amp alternator.
First step was to remove the OEM ground system from battery. I have the GM RVC (regulated voltage control) which makes it tricky. I'm doing the big three with 1/0 (actually it's the big 6 depending on how you look at it).
Almost all the 05 -13 GM gas trucks have an RVC (regulated voltage control) system (exceptions are some of the HD and diesel trucks) . It measures ground current and adjusts alternator voltage and amps according to system demands . It consists of 2 wires. OEM grounds from battery are #2 to the block and a #10 to the front crossmember for the headlights. So my do around to get the best efficiency out of the system is to squeeze two 1/0 cables through the regulator. They just fit, barely. I had to install the lugs after sliding the cable through.
What blows my mind is the little dinky #10 OEM wire (orange one on the left) that goes from stock alternator tying into another small # 2 wire to the battery/starter.
All other "big" grounds including the second battery will be going through a busbar. All battery to ground and power cables are 1/0. Start battery grounds: One to front crossmember, other to busbar. From the busbar to alternator to OEM block location to OEM chassis location, to top of block to aux battery. I spoke with the techs at Mechman and this is the very best way to get the most out of GM's RVC. Bottom line is every ground in the trucks system has to go through the RVC in order for it to work properly to regulate amps/volts to the batteries.
My first issue was a fitting problem with the Mechman alternator. The new alternator is clocked to fit 2 rectifiers (6 phase system) and 12 diodes. So this means the 2 pin plug is relocated in such a way that it hits the throttle bracket. I ended up lengthening the wire and cutting/welding the bracket. 1/16" 6013 rod and my little inverter welder did the trick. My truck is thankfully a manual transmission so I was able to chop out the automatic kick down portion of the bracket. The weld is not pretty having to do it left handed was a pain!!
Before:
After:
The Mechman is an outstanding upgrade from the OEM weak 145 max amp alternator. I have dealt with GM's poor alternators for many years. I finally bit the bullet and got one that should outlast what I have been using. For me it was simple math adding up amp pull on all the stuff I am currently and plan on using. The OEM 145 amps is barely enough to keep up with current system demands.
I compromised and went with a lower powered 250 amp model that puts out almost 200 amps at idle. Should be plenty for what I need. The 370 amp one is a beast and needs a smaller pulley to spin it up to get the amps. Mine runs on a stock size pulley. The positive post is in a different location which forces you to change out the wire to reach. The provided lug is 1/0 x 5/16 copper. I saved it but used my own 1/0 tinned copper lugs throughout my project
I also included a cheat sheet for anyone here that want's to know how to properly hook up one of these high output alts. The key is to at least do the "Big Three" and use 1/0 wire for all connections. Even with a stock alternator you will see a noticeable improvement in your charging system. . If you are running a new smart alternator and need high draw items such as winch etc, Mechman can customize an alternator with an external voltage regulator with voltage adjustment knob.
I did above and beyond and upgraded the OEM ground wire to 1/0 and did one to the stock location at the block (next to starter) and one to the alternator body. Using the busbar enabled me to use a whole bunch of 1/0 to ensure a good ground. Anyone here who has owned a GM truck knows that the electrical issues can be frustrating. Most are grounding issues from poor factory grounds. This pretty much eliminates them.
I'm getting to a point in my life to do some more mellow stuff like off the grid in my truck with some luxury. I have experience riding motorcycles and simple camping. I have a heavy background in my younger years in fabrication, temporary power, and generator field.
First off I think we all can agree that solar and lithium technology is advancing at an alarming rate. As with any project there are 100's if not 1000's of different ways to approach and achieve a project such as mine.
With that in mind I decided to go simple with room to grow in the future. For now I will be doing a basic ACR relay system with a pair of Group 78 AGM batteries fitted to factory trays under the hood.
The heart of the system will be my Mechman 250amp alternator.
First step was to remove the OEM ground system from battery. I have the GM RVC (regulated voltage control) which makes it tricky. I'm doing the big three with 1/0 (actually it's the big 6 depending on how you look at it).
Almost all the 05 -13 GM gas trucks have an RVC (regulated voltage control) system (exceptions are some of the HD and diesel trucks) . It measures ground current and adjusts alternator voltage and amps according to system demands . It consists of 2 wires. OEM grounds from battery are #2 to the block and a #10 to the front crossmember for the headlights. So my do around to get the best efficiency out of the system is to squeeze two 1/0 cables through the regulator. They just fit, barely. I had to install the lugs after sliding the cable through.
What blows my mind is the little dinky #10 OEM wire (orange one on the left) that goes from stock alternator tying into another small # 2 wire to the battery/starter.
All other "big" grounds including the second battery will be going through a busbar. All battery to ground and power cables are 1/0. Start battery grounds: One to front crossmember, other to busbar. From the busbar to alternator to OEM block location to OEM chassis location, to top of block to aux battery. I spoke with the techs at Mechman and this is the very best way to get the most out of GM's RVC. Bottom line is every ground in the trucks system has to go through the RVC in order for it to work properly to regulate amps/volts to the batteries.
My first issue was a fitting problem with the Mechman alternator. The new alternator is clocked to fit 2 rectifiers (6 phase system) and 12 diodes. So this means the 2 pin plug is relocated in such a way that it hits the throttle bracket. I ended up lengthening the wire and cutting/welding the bracket. 1/16" 6013 rod and my little inverter welder did the trick. My truck is thankfully a manual transmission so I was able to chop out the automatic kick down portion of the bracket. The weld is not pretty having to do it left handed was a pain!!
Before:
After:
The Mechman is an outstanding upgrade from the OEM weak 145 max amp alternator. I have dealt with GM's poor alternators for many years. I finally bit the bullet and got one that should outlast what I have been using. For me it was simple math adding up amp pull on all the stuff I am currently and plan on using. The OEM 145 amps is barely enough to keep up with current system demands.
I compromised and went with a lower powered 250 amp model that puts out almost 200 amps at idle. Should be plenty for what I need. The 370 amp one is a beast and needs a smaller pulley to spin it up to get the amps. Mine runs on a stock size pulley. The positive post is in a different location which forces you to change out the wire to reach. The provided lug is 1/0 x 5/16 copper. I saved it but used my own 1/0 tinned copper lugs throughout my project
I also included a cheat sheet for anyone here that want's to know how to properly hook up one of these high output alts. The key is to at least do the "Big Three" and use 1/0 wire for all connections. Even with a stock alternator you will see a noticeable improvement in your charging system. . If you are running a new smart alternator and need high draw items such as winch etc, Mechman can customize an alternator with an external voltage regulator with voltage adjustment knob.
I did above and beyond and upgraded the OEM ground wire to 1/0 and did one to the stock location at the block (next to starter) and one to the alternator body. Using the busbar enabled me to use a whole bunch of 1/0 to ensure a good ground. Anyone here who has owned a GM truck knows that the electrical issues can be frustrating. Most are grounding issues from poor factory grounds. This pretty much eliminates them.