Will 2nd battery help with Auto Start/Stop?

[skrsys]

Hi everyone,

I just got my system setup, and is working well, except for when the truck restarts during the start/stop. When the engine cranks back on, I lose audio for less than a second.

I was thinking, if I add a 2nd battery up (probably lithium) to the amps directly the sound may not be interrupted. Has anyone tried this or have a better solution. I know I can disable start/stop and I might end up doing that anyway, but I would prefer a proper solution to the problem. I'm a little bit of a perfectionist and it would irritate me knowing that I used a hack solution instead of figuring out the proper way.

Not sure if it matters, but I have a 2020 F-150 XLT.

Thanks

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[HardofWhoring]

Whatever the fix is, you don't need a second battery. Your losing accessory power as its cranking, (right?).

I know the Chevy's do this too. I didn't search, but I swear the solution is some sort of timed delay. As in it keeps power to it for an extra 30 seconds or a minute before losing power.

Are you losing power from your head unit too as its starting, or just the amps? If your head unit is staying on, is your amp's remote wire connected to the head unit or to a separate accessory wire?

 

[skrsys]

Whatever the fix is, you don't need a second battery. Your losing accessory power as its cranking, (right?).

I know the Chevy's do this too. I didn't search, but I swear the solution is some sort of timed delay. As in it keeps power to it for an extra 30 seconds or a minute before losing power.

Are you losing power from your head unit too as its starting, or just the amps? If your head unit is staying on, is your amp's remote wire connected to the head unit or to a separate accessory wire?

The head unit does not lose power. The reason I don’t think it’s the amps is because I’ve noticed my head & tail lights flicker when this happens also. It’s very brief, less than a second.

 

[HardofWhoring]

IT SOUNDS LIKE, they are wired to an accessory circuit. If they were on a 12v / power wire, they would always be on, even when your vehicle is off. When they are on accessory, they lose power when you start/ are cranking the engine. If your head unit doesn't lose power, it may already be on a delayed shut off.

Your amps should have two wires that need to be connected, your main power wire, and your small remote (blue w/white stripe/ switch wire). That blue w/ white stripe remote wire is what is losing power when you crank.

I would think you either need to give that wire a delay in shutting off, (possibly with a small capacitor, but I think Chevy owners have already gone through this), or you need to find a new place to run that switch wire.

 

[HardofWhoring]

You should be able to test that, by running that switch wire to a known hot wire, (You can tap it into your main power wire that is right there). Then go drive it and give it a try. If it doesn't happen, then that would confirm it.

 

[rovster]

Following…

 

[skrsys]

So this is my setup, I’m running 1/0 gauge directly from the battery to the fuse block:

I have a relay coming off the fuse block that is triggered by 5 amp circuit that turns on in the ACC position. Then the 10 amp out on the relay goes to the remote in’s of dsp & amps. The reason I added the relay is because I have 3 devices to trigger and wanted to make sure there was enough power. Below is an expanded pic of the fuse block:

This is a mechanical relay. I might switch to a solid state relay, just in case that might have anything to do with it.

 

[HardofWhoring]

I did that with the relay on the remote wire too, for 3 amps. I would bet money that remote wire into the relay is your problem. All accessory circuits lose power when cranking, because that starter can usually use everything you got. If you run a 12v wire to that trigger wire, and test it, that will tell you if it is.


If it was me, I would honestly just get rid of that shut off nonsense. I'm not sure how long ford has been doing it, but chevy has for 15 years or so. The problem with it is you shut off your engine, which shuts off the oil pump. The oil drains back down into the pan. Then the light turns green, and before the oil circulates back into the top of the engine, you hit the gas because traffic is pulling away, and that is most likely the highest rev some cars will get.

Its AFM on chevy and notoriously causing lifter failure. Chevy should have had a recall for it to remove, but that would probably be the most expensive recall ever.

 

[skrsys]

I did that with the relay on the remote wire too, for 3 amps. I would bet money that remote wire into the relay is your problem. All accessory circuits lose power when cranking, because that starter can usually use everything you got. If you run a 12v wire to that trigger wire, and test it, that will tell you if it is.


If it was me, I would honestly just get rid of that shut off nonsense. I'm not sure how long ford has been doing it, but chevy has for 15 years or so. The problem with it is you shut off your engine, which shuts off the oil pump. The oil drains back down into the pan. Then the light turns green, and before the oil circulates back into the top of the engine, you hit the gas because traffic is pulling away, and that is most likely the highest rev some cars will get.

Its AFM on chevy and notoriously causing lifter failure. Chevy should have had a recall for it to remove, but that would probably be the most expensive recall ever.

Ford does it a little differently, when you come to a complete stop it shuts off the engine. When you lift off the brake it turns on. So plenty of time for oil to circulate by the time you hit the gas.

Since the draw from the starter is what is causing the power to cut, that’s why I think connecting a 2nd battery to the fuse block might solve the issue. I can run another pair of 0 gauge to it.

 

[skrsys]

Just want a give an update. I ended up trying a capacitor to see if it would work before spending on a battery. The capacitor does work, the audio does not drop now when the truck cranks up on restarts.

I might go ahead and get an additional battery eventually to ad reserve capacity, but the capacitor is a proper solution to the problem.