LS charging question...

[overpaid]

After my LS swap I was driving around and the hand held for the Holley terminator X was showing about 12.2 V for battery. When I put a volt meter on the back of the alternator it shows 14v, when I put it on the battery it shows about 13v.

Just FYI, I have the original large red wire (factory wiring) connected to the back of the alternator. I am assuming that that is what carries over to the battery but I am not sure if it gets used for anything else, also FYI the car has all new factory wiring, I literally replaced everything.

Also, how the car is set up is I have 2 larger + and - wires going from the battery through the fender and then I have small distro blocks under the dash where I am using them for the holley system. So the battery comes to the one side of the block and then the other side has the connections for the holley, the fan, etc.

Anyway long story short I am pretty sure I should have upper 13s at the battery...any suggestions?

 

[kmakar]

Sorry, can't answer that one, but maybe @Alwhite00 can....

 

[Nashville Cat]

Advance Auto says :
Measuring your car battery’s voltage can be a great way to determine how charged your battery might be.
The ideal voltage with the engine running is between 13.7 and 14.7V.
With the engine off, you should get a reading of 12.6 volts.

Advance Auto Parts - Down for Maintenance

 

[Jasons69Chevelle]

Mine charging at 14.2 running a under drive.
What’s your idle speed?

 

[overpaid]

So with the holley hand held I have it set to 800 but when it is in gear at idle with foot on the brake it is about 700.

I have put a lot of miles on it and it seems fine. One thing I did realize is that the 12.2 reading when it is running and driving, that the hand held is reporting that is with the fan on. When the fan goes off it reads 13 while driving, which is still low....

 

[overpaid]

Advance Auto says :
Measuring your car battery’s voltage can be a great way to determine how charged your battery might be.
The ideal voltage with the engine running is between 13.7 and 14.7V.
With the engine off, you should get a reading of 12.6 volts.

Advance Auto Parts - Down for Maintenance

Yea I was definitely thinking it should be over 13

 

[Jasons69Chevelle]

This is all new battery have you taken it on a long enough drive to fully charge the battery?

 

[overpaid]

Yea I would say I have put on at least 100 miles since the swap already. I have been driving it around a lot.

 

[overpaid]

So you are saying the battery is bad? Not able to take the charge?

it is about 1 year old FYI

 

[77cruiser]

Probably won't matter, but put a charger on it for a day or more.

 

[Jasons69Chevelle]

No I don’t think the battery is bad (could be) just maybe not fully charged after setting for awhile. After 100 miles I would think it’s fully charged though.(maybe not)

 

[Jasons69Chevelle]

What gauge wire do you have running from the alternator to battery? I’m running 0 gauge about 16 inches. And 2/0 from the battery to the starter.

 

[overpaid]

I have to double check but it is not that big that is for sure, it is whatever the factory used back in 66 lol. Maybe I should run my own line like you have, 0 gauge.

 

[overpaid]

Man, 0 for sure, from the alternator? My starter wire is 2/0 for sure but the alternator wire is at most 10 gauge...

 

[Jasons69Chevelle]

Probably would be a good idea. The factory wiring was for 61 amp alternator maybe 100 amp. That LS alternator is probably pushing 180 amps or more.

 

[overpaid]

Wow okay I did not know that, I will order up some wire and take care of that asap and let you guys know. Thank you everyone for your help!

 

[Alwhite00]

I'm around 13.9 - 14.2 while running depending on rpm. As long as the alternator is excited and charging you should be good.