Battery cable vs OBC

[Stevegrmich]

Originally Posted by anix

So running a second cable in parallel with the one passing through the OBC shouldn't change what the OBC sences then right? As long as this little trick works I guess there is no sense in over analyzing it. But for future reference I would be curious as to just how it works. The OBC must create a current flow somehow so that it can calculate pac V?? Anyway thanks for the great info. It is great to learn something new everyday..now if I could only figure out how to remember it. When you get a few years on you watch out you may suffer a little CRS lol.

. . . from the CC manual . . .

"The onboard computer, having recorded the amount of energy consumed as the vehicle was used, directs the
charger to replace exactly the amount of energy needed to fully replenish the batteries. The charger then
shuts off automatically, preventing the possibility of either undercharging or overcharging. The computer
accomplishes this by detecting when the exact amount of energy necessary has been returned to the batteries."

. . .

[anix]

That is why I am asking. So what is your suggestion for running #2 cables because I doubt one will pass through the hole. It looks like the #4 that's on it now is really tight???? If in fact it does use a hall effect sensor then it may work. The best I can remember a hall effect sensor is just a switch. Magnet field rises it turns on and when it drops it turns off. Like a crank sensor on a car. It turns off and on as the mag. passes. I come nearer thinking that there is a coil around the cable pass through sort of like a clamp on amp meter pickup.

[anix]

So Steve in your opinion will a parallel cable effect the ability of the OBC and charger to do their job??

[scottyb]

It has been proven that the route around cabe has caused charging issues with SOME of the late model OBCs. Early OBCs did not calculate use into the recharge function, they were not adversely effected by re-routing some of the pack draw around them. I do not know what years are effected, we use an obc stud on all years to be safe. This is just a piece of threaded rod positioned thru the OBC with your big cables bolted to each end. SOme will argue it needs to be brass or copper but I don't see these same people complaining about their steel battery studs, lol.

[caokgafamily]

Just go to lowes and buy a stud bolt and be done with it.

Steve

[anix]

Thanks Scotty. That was going to be my next question.Has anyone used some sort of bulk head connector and how did it work. You just answered that for me. I think that is the route I will take. Of course that does add two more connections. Another thought, since there will only be 4 or 5 inch left to go after the cable passes through the OBC before it connects to the controller. I may check the dia. of the bare #2 cable to see if it would pass through the OBC. If so I may consider removing the insulation, use a short piece of shrink wrap long enough to get through the OBC then re-insulate the remander with what I stripped off, secured with a heavy shrink wrap. Just a thought???

Originally Posted by anix

It appears that the neg battery cable passes through the OBC. If this is so what purpose does this serve. I plain on going to #2 cables, will they pass through the opening or is it ok to go around the side of the bulk head???
Thanks
AL

not to be seen as stupid but...
does that cable really need to be upgraded to #2 cable ?

[anix]

I am upgrading to a 500A Alltrax controller and the general consensus seems to be to upgrade to #2 cables also.

[scottyb]

You know you are over thinking this, right?
Yes 2g is recommended but you can get away with 4g if you are cutting corners particularly on 48v.

Originally Posted by scottyb

You know you are over thinking this, right?
Yes 2g is recommended but you can get away with 4g if you are cutting corners particularly on 48v.

so i'm not stupid ? wait.... don't answer that !!!