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New here but I got a question I’m currently running two h7 AGM batteries from interstate with a aftermarket alternator from JS alternator 


I have my batteries wired from alternator to battery #1 then from battery #1 to battery #2 all done with 1/0 welding cable and big 3 done 


but I was told I should have pulled both power cable straight from the alternator 


he’s saying to wire it from alternator to battery #1 then again from alternator to battery #2 


will this make a difference? 

not running much and not having any issues just curious on the logic behind his idea


all I have is a single audio pipe bdc4 12” and a hd3k stuffed into my gen 1 tundra 

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So, if you wired them separately like that, you're not using both batteries as one. Right now, the way you have it wired is correct. It essentially turns 2 smaller batteries into 1 bigger battery. If you wired them separately, you'd still have 2 smaller batteries. 

Some people will sometimes wire them separately like that to protect the battery under the hood from the system, as to not putting any added stress on the starting battery. Downside is, like I stated above, You wouldn't be using that battery to help power your system. 

Now, some people will wire both batteries together, but still have a dedicated cable from the alternator to each battery. This is fine to, because wired together you have basically one battery, and current isn't linear, so the 2 batteries make sure to balance out the voltage between one another. So both will charge like normal. For the same reasons though, hooking up your alternator to the first battery will yield you the same results (as long as you have a sufficient amount of copper between the 2 batteries to make the transfer of current seamless, but that's another question).


Edited by Dafaseles
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It doesn't matter. It's a parallel circuit either way so to the alternator sees them as one. 


That being said, one wire from alt to batt1 then from batt1 to batt2 means you have to run less wire.


Edit: Assuming your wire can carry enough current. 

Edited by MrSkippyJ
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