How to keep your electronics buss high

[Bruizer]

Hello All,

We were having trouble with the Raymarine electronics when starting the engine. The abrupt DC system voltage drop that accompanies engine starting was rebooting the E120 multifunction display, sounder, and autopilot. The original Marinette wiring did not have separate cranking and house circuits. Just two batteries and a OFF-1-ALL-2 switch that fed the engine and accessories. Fixed the problem by installing a simple relay and a battery. I decided to call it..."Smart Start" (SS).

A sealed rechargeable battery provides supplemental voltage to the electronics buss via a relay contact when the engine is cranked. When the ignition switch is released, the relay drops out and and the SS battery is recharged by the alternator. When on shore power the 13.8v float charger keeps the SS battery topped off. Got the battery, relay, and charger on eBay for $50. Installed it in the head under the counter top.
Works like a charm. Can't even see a blip on the E120 display when starting engine.

 

[BaileysBoat]

Re: How to keep your electronics buss high

Very nice, but if you wire the electronics to the house battery it wouldn't be required.

 

[Bruizer]

Re: How to keep your electronics buss high

Very nice, but if you wire the electronics to the house battery it wouldn't be required.

You are right. Gonna make some changes in the off season. DD

 

[John_S]

Re: How to keep your electronics buss high

Neat and simple. Nice work. Even after you wire to house battery, it is not a bad thing to have a third battery for electronics and communications.

I have scrounged similiar batteries and parts from UPS's. The SLA charge doesn't last as long as equivelent size lead-acid, but you don't have to worry about spillage.

 

[Bruizer]

Re: How to keep your electronics buss high

Neat and simple. Nice work. Even after you wire to house battery, it is not a bad thing to have a third battery for electronics and communications.

Thanks. I would rather be over powered anyday. DD

 

[Bruizer]

Re: How to keep your electronics buss high

BTW, I have a Newmar StartGuard NS-12-20 for sale on eBay...cheap.
http://www.newmarpower.com/pdf/Manual-NS-12-20.pdf

 

[bruceb58]

Re: How to keep your electronics buss high

adammatthew431,

Start a new post with your question and explain the application you are doing this with. I really couldn't see how mosfets fit in with the original poster of this thread or anything for that matter.

 

[Bruizer]

Re: How to keep your electronics buss high

Just to let you know that this still works great....as long as you remember to keep the battery charged.

Was out fishing over Labor Day and my chartplotter dimmed while starting the engine. The trickle charger had vibrated out of the 110 socket.

DD

 

[kahuna123]

Re: How to keep your electronics buss high

Feed power from both sources to the buss with a diode in each circuit. Works great. Also works with independent twins. Feed both to the buss with a blocking diode in each circuit. That how Cabo does it. Knowing what that E120 cost I don't blame you.