Radar power source

[Jim Gandee]

I discovered the power supply for my Garmin 12v HD radar is the house battery bank. Seems odd to me. I'm thinking the radar should be powered by the starting batts as they are constantly being charged when the engine in running and that's when the radar is bring used. What am I missing!

 

[AusCan]

It all depends on your charging setup. If your starting batteries are the only batteries being charged while the engine is running it should run off them.

Some boats have selectable charging from their alternator to the starting or house batteries. Some boats have battery to battery charging from their starting to their house batteries while underway. Lots of possible setups.

 

[psneeld]

If you leave you radar on all night.....no the best to be on the start battery.

Not the best setup if you have no way to charge your house when the engine is running or at least combine then when necessary.

 

[Jim Gandee]

Why would one wish to leave the radar on all night, presumably with the main engines not running?

 

[psneeld]

positioning, collision avoidance, detecting unwanted visitors, etc.......

 

[hmason]

Most radars can be used as an (insert dirty word) alarm.

(Didn't want to say anchor.)

Howard

 

[River Cruiser]

I have twins, 1 charges the start bank the other charges the house bank. In my setup I don't see that it makes any difference which bank powers the electronics other than for a anchor alarm. If I forgot to power off something and it ran a battery down better the house than the start.

 

[N4712]

We sometimes leave our radar on at night, its powered off our house bank. Iv'e never heard of connecting electronics to the starting bank.

 

[sunchaser]

Iv'e never heard of connecting electronics to the starting bank.

Done all the time for the past century or so. Yes there were boats before inverters. I've had several with a few having a start battery for each engine and a genset when needing power. My current vessel is set up to be house bank and inverter free, things do go bad so redundancy is nice. God bless my genset!

 

[High Wire]

With the electronics connected to the start battery, every time you start the engine you dip the voltage down around 9 or 10 volts. Some electronics can handle that, some can't. For example on my skiff, the Humminbird depthfinder locks up requiring a complete restart.
I would stay on the house batt.

 

[O C Diver]

You really need to understand how your boat electrical system works as to whether there is a problem. On my boat the only thing on the engine start battery is the engine with it's own separate alternator to charge it. When something happens in the middle of the night, I want to be able to turn the key and know it's going to start regardless of what I may have left turned on.

Ted

 

[sunchaser]

With the electronics connected to the start battery, every time you start the engine you dip the voltage down around 9 or 10 volts. .

Or do as was done routinely in the good old days, start engines before turning on instruments. Or as is done today on tens of thousands of house bank free Searays, Intrepids, Ospreys, Grady Whites, Whalers, Pro Line, Hewes Craft, Fountains etc used for fishing, skiing and fun activities.

 

[Jim Gandee]

Thank you for all of the comments/suggestions. I will leave it connected as is for now.

One thing though, when electrical draw items are connected directly to the house batt bank don't they then become " invisible" to the Link system with the resultant drawn amps uncounted?

 

[C lectric]

One thing though, when electrical draw items are connected directly to the house batt bank don't they then become " invisible" to the Link system with the resultant drawn amps uncounted? Yes, they become invisible.

 

[Wxx3]

Thank you for all of the comments/suggestions. I will leave it connected as is for now.

One thing though, when electrical draw items are connected directly to the house batt bank don't they then become " invisible" to the Link system with the resultant drawn amps uncounted?

No. Not if your battery monitor is installed correctly, as the shunt should be on the negative side, connecting the battery negative with the house system.

Also, all the adice above is good. the only thing on your start battery should be your starter. Why takes chances you do not need to take?

Yes, I have had to sleep with the radar on a number of times. Didn't sleep very well though

 

[Jim Gandee]

No. Not if your battery monitor is installed correctly, as the shunt should be on the negative side, connecting the battery negative with the house system.

In my case the radar neg is connected to a bus prior to the shunt. I'm not sure how the Link is able to see those amps being drawn?

 

[markpierce]

I'd never want a continuous draw from the starting battery. Want it fully-charged to assure engine start-up. Engine's alternator should charge both starting and house batteries.

 

[TDunn]

When I wired my boat I ran the alternator output directly to the start battery. The start and house banks are connected by a battery combiner so that both banks are charged when the alternator pulls the start battery up above the combiner's threshold voltage. In other words, the two banks are connected WHEN the engine is running and separate when the engine is off. I also put in a switch to allow me to interconnect the two battery banks so all the batteries can be used for engine starting if needed. ALL electronics, etc are connected to the house bank so that the start bank isn't drawn down by anything except engine starting.

For redundant charging I have my cabin top solar panels wired to a dual output controller that charges both battery banks. It is split 90% house, 10% start. I do not have shore power or a generator. 200 watts of solar panels on the house top lets me leave my refrigeration on full time and keeps the batteries at 100%.

In your case, I would leave the radar connected to the house bank.

 

[Jim Gandee]

I have left the radar connected to the house batts for all the reasons mentioned. I certainly understand the importance of maintaining the starting batts in a fully charged condition. With a combiner switch (house and starting) if the starting batts are down I can always add the power of the house and if that fails I do have the generator with its own dedicated battery. Thank you all for the excellent comments and suggestions.