Hardin Thicke

Interested in adding an isolated 2nd battery. Was wondering if anyone has experienced charging system problems after adding one? Codes or Check Engine Light? Planning on adding a Yellow Top with a Hellroaring battery isolator.

d1nonly34

I added a yellow top to the factory battery without a relay isolator and had no problems whatsoever. That was in my 07 Tahoe now I have an 08 and I plan on adding a Kinetik battery but probably with a relay isolator cause i dont want my system to be sounding if my car isnt cranked. Are you using it for a sound system or electronics or accessories?

Hardin Thicke

That's good to hear. I was concerned as to how the intelligent charging system would react to the load of the second battery. I'm using it for amateur radio gear which pulls about 25A on transmit, but less than an 1A on receive.

socaliguy81

Adding a second battery isn't going to help you with your required 25 amps.. amperage comes from and always will come from the alternator. Adding a second battery without upgrading the alternator will place your alternator under greater stresses shortening its life and reducing its effectiveness. I'm not sure if the Tahoes that came with the dual batteries have beefier alternators than those without the second battery? Anyone?

Anyways, adding a second battery helps mainly one thing... Capacity: The ability to use reserve power longer without the vehicle running.

If you are looking for amperage, start with the alternator. This goes for you stereo guys as well.. adding batteries or caps without addressing your alternator is counter-productive at best.

in2pro

you are correct, but I'm going to go out a limb here and speculate that Hardin is using the equipment with the engine off and needs the extra power.. the high current draw is pulling the single battery down quick and adding the second will buy him some non-engine running time...

Hardin Thicke

Correct. I will be using the equipment most of the time with the engine off. The aux. battery will be isolated from the starting battery by a Hellroaring Technologies, BIC-95150A Battery Isolator. Charging current from the alternator to the aux battery is limited by the device, so it shouldn't overload the alternator. I was concerned about how the charging system would react to another battery, but I've since been informed by the manufacturer that the device simply looks like another load on the vehicle's +12V system. We'll see... New Yellow Top is in hand, and Isolator is in transit now.

in2pro

take pics and document as much as you can, part numbers and web site too!

d1nonly34

does anyone know what the factory amperage output on our alternators are?

in2pro

Check your RPO codes int he glove box

KW1 GENERATOR 160 AMP
KW2 GENERATOR 124 AMP
KW3 GENERATOR 135 AMP
KW7 GENERATOR 170 AMP
KW9 GENERATOR 190 AMP
KXB GENERATOR 100 AMP, DUAL