Added 2nd battery voltage drops still

I recently decided it was time to install a 2nd battery. I already have a HO alternator, and the big 3 upgrade. I installed everything with 1/0 and a 200 amp relay. I then noticed my sub amp was going into power protect mode under high volume.

I metered the 2nd battery and get roughly 9v. If i test the voltage supplied to the relay im experiencing 14v+ and if i meter the outgoing of the relay i get the 9v still. Im not sure whats going on any help would be appreciated.

This is the relay i installed http://www.oznium.com/relay200

did you upgrade the power wires going from the alternator to the battery?

alienyoungjr wrote:

did you upgrade the power wires going from the alternator to the battery?

Yea, thats what the big 3 is. All the stock wiring is replaced with 1/0.

What Amperage is the Alternator ??? How many watts for the amps ???

Relay input is 14V and relay output is 9V....sounds like you're having a relay issue.

I talked to someone who is an installer and they said the 200 amp relays make a very loud clunk when turned on. I dont remember it every making a loud noise when turning on (i have it wired to the ignition). I'm going to jumper the wire when i get home to make sure its getting turned on.

I think the loud noise is normal (the electromagnet).

Hope someone has and idea, because I'm stumped.

How exactly are you using the relay? What's the low current input signal (ignition, headlights, etc) and what's the high current output (constant amp power, main power, etc)?

I'm thinking the amp is pulling too much , thats dragging the voltage down as the alternator can't keep up

yeah maybe your H.O. alt is going bad

Is your second battery voltage only at 9v? If so, you have a serious problem, and depending on what battery you have, your second battery may be dead. Which ignition wire do you have that relay connected to? It sounds like you have your sound system hooked up to your second battery, and the relay isn't getting tripped, so that second battery is remaining disconnected from the rest of your vehicle, therefor it's not getting charged. At this point, your amps are going into protection mode because they are being underpowered (9v isn't enough to drive them). If you got a red top or yellow top battery, you may need to invoke the warranty on the battery.

I'd double check your remote wire to make sure you connected it to the correct wire. There are more than 1 ignition wires. Some aren't on at all times (for example the wire that goes to the starter). If it's connected to that wire, the relay will only click on for as long as you're starting the engine. Once it's started and you release the key, the relay clicks back off. The easiest method is to find a relay output on your interior fuse panel that's off when the car is off, but on when the car is running. This way you know it will always be on when your car is on, and you're not tapping into the factory wiring.

Your connection should be as so:

Main Battery and Secondary Battery NEGATIVE lead grounded to the vehicle.
Main Battery POSITIVE lead going to alternator output.
Main Battery POSITIVE lead going to standard components it always has.
Main Battery POSITIVE lead also going to input side on 200 amp relay.
Secondary Battery POSITIVE lead going to output side of 200 amp relay.
Secondary Battery POSITIVE lead going to amplifiers.
200 amp relay remote lead hooked up to your fuse panel on a port that is only on when engine is running/key is turned to the ON position (not ACC).
200 amp negative lead hooked up to ground on vehicle.

Both the remote and the negative lead on the relay does not need to be heavy guage. 18 guage should be plenty.

Also note, you do not want to use the remote power on for your sound system to be the remote feed for the relay. If you do this, the relay will only click on when you have your sound system on. You want the relay to click on whenever you are driving, even if the sound system is off. This way the alternator can charge your secondary battery without a constant draw from the sound system. Depending on the output of your alternator, you may need to drive your car for a while every once in a while with the sound system off, just to bring your battery up to par.

If it's not hooked up in the above method, then there would be your problem =)

if your not tripped the big 200A relay, i believe you could use a smaller relay to boost some larger current to the 200

so if you have a 40A 4pin laying around, use to to boost the signal to your larger relay

i could be wrong, although i believe this'll settle your problem if the 200A relay isn't magnetizing.

And the purpose of that would be? That relay should take waaaaay less than an amp to trip. No point in putting another relay in to trip the relay..