RADAR system battery dying

[Cricket Too]

I have recently installed a Raymarine C80 RADAR, GPS, Depth system. I intsalled it on it's own tractor battery that I put down in the cabin. The boat has twin outboards and two batteries, one for each engine on each side of the boat in the stern. The way the boat is setup ( for some reson) is that the starboard battery powers everything under the dash and all of the electronics on the boat. <br /><br />So when I hooked up the separate tractor battery I used a battery combiner and hooked into the starboard cranking battery up under the dash, so the combiner could get the charging voltage from there, instead of running a wire all the way back to the stern ( about 15 feet). <br /><br />The problem I am having now is that the tractor battery keeps dying on me, even though I can see the combiner lighting up indicating that the batteries are in parallel and charging voltage is present. I have not yet checked at the tractor battery for exactly what kind of charging voltage I'm actually getting, but it's obviously not enough. The combiner only switches and puts the batteries into parallel when it sees charging voltage of 13.1 or more, so I must have at least that. I'm thinking I'm either just not getting enough voltage to sufficiently charge the battery or since it's just a lawn tractor battery and basically meant for only starting a tractor momemtarily, that it just cannot support the drain of the RADAR, GPS and depth sounder, and gets drained pretty quickly and cannot recover based on just running the engine to move from spot to spot, or possibly a combination of both. Just looking for a some experts that may have an opinion, as this is the first system like this I have ever installed. Thanks, Mike.

 

[briannh1234]

Re: RADAR system battery dying

With your current setup one of 2 things is happening -<br /><br />1) you not running the motor long enough to charge the battery.<br /><br />2) the battery may be old, the wrong type, or just not big enough for the job.<br /><br />Try testing #1 first. Remove the battery and charge it with a smart charger overnite. Reinstall the battery and see if it works better. If it does, then the combiner may not work for you without longer run time. If the battery does not work any better then you may want another one.<br /><br />Seems to me you want a deep-cycle battery anyway. Starting batteries can only be run down so many times before they die. Since you killed it a couple times allready it may just be dead now.<br /><br />Walmart has a nice selection of cheap batteries. Other's on this board recommend trojan brand batteries but I have never used one myself. Optima brand batteries are not recommended.<br /><br />Good luck.

 

[waterone1@aol.com]

Re: RADAR system battery dying

In my opinion a radar unit is a pretty hi current device. I can't imagine a tractor starting battery being able to run that unit for very long. You need to have it run from a good sized deep cycle battery.

 

[Boatist]

Re: RADAR system battery dying

Your battery is way too small to even run the Radar. With the Fish Finder and GPS I am suprised it works at all. Get a group 27 Deep cycle. Also what is the amp output of your alternator?

 

[amirm]

Re: RADAR system battery dying

The C80 setup with full backlight is probably using up 10 amps. That is a ton of current to be provided by the little battery. With the primary battery getting charging priority, and some amount of voltage loss with the long run, this setup will not be a good practical solution.<br /><br />Do you run the instruments without the engine running? If not, then you can share the starter battery on one side and not bother with this extra battery. If you do run it without the engine running, you should still be OK if that battery is sized correctly and you have a switch that can let the engine start from the other battery.<br /><br />Amir