momentary low volt problem @ start-up

All two way radios that are hooked to the battery or ignition wire will shut down for a short time while cranking the engine. One way to get around this would be to install a second battery dedicated to the radio and being charged through an isolator. Another way is to delay the radio from turining on until the vehicle has started. This can be accomplished with a timed relay setup or with a sence circuit off the alternator.

I hope this helps in your decision,

Tom

I actually run 2 batteries and my stereo plays right through startup. even with the system cranked...however, I have my deck directly powered, bypassing the ignition wire, and running everything off constant 12v...

some people think its a pain in the ass to have to shut your stereo off manually everytime you get out of the car, but I prefer it that way...

I think that the actual ignition signal cuts everything out so that it gets as much of the batteries power as possible...you could try wiring the 2ways directly to the battery and using a toggle to turn them on and off...I am kind of grasping at straws here, but not coming up with anything too fancy...maybe try the direct wire and see if the radios turn off or not...it may just be that the battery cant produce enough juice through startup to maintain the radios...

I just thought of this, re-reading all the posts here...would it be possible to run the radios off of a cap and wire in an isolator that could be used to isolate the cap itself only during startup?

do the radios have to be on 24/7?

I like that thinking along the lines of the isolator. I wonder what the lowest amperage is that isolators are available. The radio probably only draws .5amp max while idle.

To answer your question the radios are on anytime the vehicle is on duty and when the officer starts up the car the low voltage de-activates one of the radios critical functions that the officer then has to manually re-enable. If he does not hten the radio does not operate properly and creates a real safety issue in emergencies.

Let me know about the cap. isolator. I spoke to Monster earlier today and their tech dept is hopeful that a 1 farrad cap may help the problem. I am going to try to do some footwork to a local high end audio shop and bend their installation depts. ear on the subject. Since around 100 cars are affected they could make a few bucks off of supplying me with the equipment so maybe they will be willing to help.

I appreciate your help I know this is a little off the beaten path for this forum but anything is worth a try.

that sounds good to me personally, but I am no pro...mebbe some of the longstanding 12v gurus could field that one and shed some light on this shady situation...

anyone?

I think since the radio is fused at 20 amps if I install 3- 10amp diodes in parallel then I can achieve my goal as long as the 1 farrad cap will provide the needed power to the radio alone for the instant @ start up. I also seek enlightenment from the gurus!

Speak o great ones!!!