HDS-8 powers off

[jason007]

What does it mean if my Lowrance HDS8 powers off when cranking over the motor? It doesn't do it everytime but had done it a few times.

[Ed Carlson]

This is a common problem with modern graphs and larger outboard and inboard motors seen on boats today.

You very likely need a higher cca rated starting battery, or a new battery. Voltage spikes +/- will shut down most modern graphs and other electronics at 10 V in order to protect themselves from damage.

I recommend you replace it with a starting battery of a ratting of 1000 CCA.

That will do it as long as all your wiring connections are good to your graph. So it is always wise to recheck your fuse line and be sure all the connections are good.

It could just be a loose connection too...start there. I suspect it's time to upgrade your battery though.

[Nick Kuhn]

It's the battery. I have a similar problem with my 798CI. I just turn it off to start the motor then turn it back on when the motor runs (as it tends to lock-up as opposed to turning off). A bigger battery would help but ask yourself if the minor inconvenience justifies the price. It doesn't happen if I run the motor often enough to keep it warm so it turns over easily.

[Chode2235]

With these larger graphs hooked to your cranking battery, is there any concern that you will run it dead? Or is the issue simply the power spikes?

Probably a dumb question, but thought I would ask anyway.

[Nick Kuhn]

In order to affect starting you need to drain about 20 Amp/hours from the battery (assuming it is fully charged to start). The current draw on these units is ~500mA, so if your graph was the only thing draining your battery you should be able to go 40 hours before you have a problem. So no, you won't go dead unless you are running lights, a radio, bilge/livewell pumps, etc.

[Ed Carlson]

Drawing it down may lead to a minnimum voltage issue with the main motor too, larger motors may go..click...clink or nada-zip...nothing at all...but the graph may still be running. Been there done that..so we upgraded to the 1000 CCA and no more worries either way.

It really depends on the minimum voltage required to spin the motor or if it requires a minimum to even try to crank. Larger 4 stokes, you will run into this.

[buddha]

I've got the same issue and I run a larger 4 stroke. I have a new Optima battery but I bet I don't have one that's 1000. It only seems to be a problem for me if my boat isn't used for a week or couple at a time. I do have a bunch of stuff hooked up to my starting battery so I'm sure there is more draw then normal but I do need to check my connections every once in a while because they do work loose.

[Corey20]

Thats why I just run 2 main batteries in my boat. I can have all 3 graphs(8" and 2-7") on, livewells and radio for a few hours and there aint a glitch. I never even had a problem when running one battery and I think my interstate is 675cca.

[tunrevir]

One thing I have discovered with a Garmin unit I have in my boat that with the backlighting display on high for a few hours is that it automatically shuts down and I think it is due to the heat and a capacitor(sp?) Worked fine after I toned the screen down.

Tuinrevir~

[Fish Head]

I've had it happen where my battery went dead on the water. I had 2 days of fishing with 2 graphs and live well and very little use by the big motor. I've since replaced that battery several years ago.

The graph on my bow turns off many times when I start the big motor. Now I know why. I'm not going to hurry off and buy a different starter battery, but it's good to know why that happens. When I do replace it I'll make sure I get a 1000 cca.

[Dale Rueber]

I frequently get a "Low Voltage" popup warning on my HDS-8 when i start the motor but the HDS-8 has never turned off. Not sure of my CCA but I think it is aroung 600.

[jason007]

I took a look at my cranking battery and it is made by Trojan and is a 825 CCA. I will look around for a 1000CCA battery and see what happens. I do happen to have a second marine cranking battery in the garage, is there any harm in wiring them in parallel? Will the alternator on the motor charge both okay? Just wondering if I have the room if it would be better to do two batteries in parallel or just get a new 1000CCA batt.

[Ed Carlson]

I would load test both first, see if your working with two healthy battery's first. The 825 should be good enough, if healthy, as long as your not running a lot of accessories at the same time. 1 1000 CCA in top conditions would do it for sure.

Many boats do run 2 if they have the room to do so. So that is an option. I would just be good and sure they are both healthy before you go through the work of the dual installation.