Chevy Colorado Dual Battery Cheat

[North40overland]

For my fellow Gen 2 Chevy Colorado Owners I wanted to share a low cost alternative to installing a dual battery system. Because the Colorado comes in both a diesel and a gas model, and GM likes to use the same parts as often as possible; the battery tray in the gas model is large enough to accommodate the massive H8 battery required for the diesel. This being the case you can run down to your local auto parts store and pick up an H8-AGM battery and just drop it in your rig with no fuss and zero modification. The H8-AGM I selected has 95 amp hrs, compared to the 70 amp hrs of the OEM battery. This is significantly more capacity over the OEM for 200 bucks and 5 min's of effort. While it is a heavy beast of a battery it is still lighter than 2 (or roughly the same weight at most) batteries and works like a charm. I have been running this setup for about 6 weeks now and no issues. It runs my fridge, tent lights, awning lights, etc. I have 100 watts of solar charging it when I can but even without it I have noticed a real positive gain on the volt meter thanks to this simple and (relatively) inexpensive upgrade.

 

[huachuca]

Thanks for the suggestion and it’s always good to hear from someone with hands on experience. I’ve got a 19 ZR2 double cab gasser and have been considering this upgrade but have heard of possible issues due to different charging profiles between the diesel and the V6. From what I’ve been able to determine with on line part number searches, the OEM alternators have different part numbers and amp ratings, 149 for the diesel and 150; for the gas. I’ve turned my share of wrenches in the past but have minimal confidence in my abilities regarding the modern electronics on today’s new vehicles. Thoughts.???

 

[North40overland]

Thanks for the suggestion and it’s always good to hear from someone with hands on experience. I’ve got a 19 ZR2 double cab gasser and have been considering this upgrade but have heard of possible issues due to different charging profiles between the diesel and the V6. From what I’ve been able to determine with on line part number searches, the OEM alternators have different part numbers and amp ratings, 149 for the diesel and 150; for the gas. I’ve turned my share of wrenches in the past but have minimal confidence in my abilities regarding the modern electronics on today’s new vehicles. Thoughts.???

It is a fair point. I was worried about the starter motor as well. I have a buddy in Missouri (where I grew up) that has a 17 ZR2 and he did this swap about a 2 years ago (this is where I got the idea, and who inspired me to switch to this truck from my JK) and he has reported no issues so far. I am not sure if this would be considered a warranty violation but I am keeping my old battery in the garage on a trickle for a while just in case something breaks (I can swap it out to avoid any questions if need be). Jason swears I won't have any problems but only time will tell.

 

[MazeVX]

Thanks for the suggestion and it’s always good to hear from someone with hands on experience. I’ve got a 19 ZR2 double cab gasser and have been considering this upgrade but have heard of possible issues due to different charging profiles between the diesel and the V6. From what I’ve been able to determine with on line part number searches, the OEM alternators have different part numbers and amp ratings, 149 for the diesel and 150; for the gas. I’ve turned my share of wrenches in the past but have minimal confidence in my abilities regarding the modern electronics on today’s new vehicles. Thoughts.???

So usually there are different types of agm batteries, those who are made for automotive applications and those for other stuff like solar etc.
I know the ones for automotive don't cause trouble, I swapped several vehicles from standard to agm batteries sometimes with 50% increased capacity and never had a problem, the charging curve is basically identical enough to lead acid that it works flawless.
Stay away from gel or lead crystal batteries directly at the alternator, they have special needs and charging directly can lead to catastrophic failure.
This is a very coarse overview, so please don't nail me down on the words about gel and LC...

 

[North40overland]

So usually there are different types of agm batteries, those who are made for automotive applications and those for other stuff like solar etc.
I know the ones for automotive don't cause trouble, I swapped several vehicles from standard to agm batteries sometimes with 50% increased capacity and never had a problem, the charging curve is basically identical enough to lead acid that it works flawless.
Stay away from gel or lead crystal batteries directly at the alternator, they have special needs and charging directly can lead to catastrophic failure.
This is a very coarse overview, so please don't nail me down on the words about gel and LC...

This is extremely helpful. Thank You!

 

[MazeVX]

This is extremely helpful. Thank You!

No problem! There's a lot to know about batteries, some can work better with the constant low current draw that is typical for fridges and overlanding applications, some are more towards high current. Your best chance is asking someone with more knowledge local since I'm not informed about the batteries available for you, otherwise I would point you to a good battery.

 

[madcratebuilder]

I installed that same Duralast last spring. Been involved with a few online discussions about the so called charging profiles for gas vs diesel engine/battery (LA vs AGM). The automotive AGM is a lead acid battery with the acid solidified in the matting inside the battery.

I have yet to find any info FROM GM about the different charging profile. Many online sites talk about the different charging rates the AGM needs or it well fail, most these are for deep cycle or "house" batteries.

I have "smart" battery charger, a "smart" battery tester. The tester tells me I'm at 86-90% SOC (state of charge) and 90-92 SOH (state of health) in my normal daily driving, mostly short trips of 10 miles or less. My typical battery voltage after sitting overnight is in the 12.7-12.8 range, my cranking voltage is generally 11.2 V.

The Colorado is a smart charging system controlled by the BCM and ECM. It is normal to see 15.1V after startup, dropping to 14.8-14.2. If tyou drive long enough it drops to 13.8-13.4 and finally after a hour or so it drops to 12.8. There are 5 or more "modes" for charging, you can find this info online. We have a "battery sensor" on the Neg battery cable that monitors the battery and sends this info to the BCM.

I did notice that my displayed charging voltages are different with the AGM vs LA battery. If I put my AGM charger on the truck it takes about 3 hours for it to push that last 10% charge in to the battery. I haven't done a straight 3 hour drive since installing but I think that would bring me close to the 100% SOC.

Time well tell if these AGM's well survive in out trucks, several owners are on year 3.

 

[North40overland]

I installed that same Duralast last spring. Been involved with a few online discussions about the so called charging profiles for gas vs diesel engine/battery (LA vs AGM). The automotive AGM is a lead acid battery with the acid solidified in the matting inside the battery.

I have yet to find any info FROM GM about the different charging profile. Many online sites talk about the different charging rates the AGM needs or it well fail, most these are for deep cycle or "house" batteries.

I have "smart" battery charger, a "smart" battery tester. The tester tells me I'm at 86-90% SOC (state of charge) and 90-92 SOH (state of health) in my normal daily driving, mostly short trips of 10 miles or less. My typical battery voltage after sitting overnight is in the 12.7-12.8 range, my cranking voltage is generally 11.2 V.

The Colorado is a smart charging system controlled by the BCM and ECM. It is normal to see 15.1V after startup, dropping to 14.8-14.2. If tyou drive long enough it drops to 13.8-13.4 and finally after a hour or so it drops to 12.8. There are 5 or more "modes" for charging, you can find this info online. We have a "battery sensor" on the Neg battery cable that monitors the battery and sends this info to the BCM.

I did notice that my displayed charging voltages are different with the AGM vs LA battery. If I put my AGM charger on the truck it takes about 3 hours for it to push that last 10% charge in to the battery. I haven't done a straight 3 hour drive since installing but I think that would bring me close to the 100% SOC.

Time well tell if these AGM's well survive in out trucks, several owners are on year 3.

Thank you VERY MUCH for the info!

 

[MazeVX]

Longest I run a agm was 6 years, flawless. Now running the same type but bigger in the jeep for 3 years, flawless. Works perfectly for the fridge and casual smartphone charging