Depth finder quits when I start motor

[hammertime905]

Recently my depth finder stops when I start my main motor. Is that an indicator that my starting battery is starting to die or something else? The battery starts my motor fine and doesn't seem to be weak.

Thanks for your input.

[flntknp17]

I had the same issue a couple years ago. It turned out to be a battery that was near death...........I replaced the battery and it has not happened since.

Matt

[PRD1]

Most units will drop power if the voltage gets below about 10.5V or so, this is sure the source of the problem since when you start the outboard it puts a heavy load on the battery. If your sonar has an option to display voltage you should turn it on (it's in the overlay options, bottom of the list on Lowrance units). You will see the voltage drop as you crank the outboard. Check the starting battery for state of charge, it will start the outboard with even a 25% charge or so but the sonar will drop out.

[my4x4yj]

DITTO, battery going, the experts say hot weather is harder on a battery than cold weather.

[geareng]

I had the same issue, I also replaced the battery but still occasionally had the same issues. What finally solved my problem was that I put di-electric grease on my connections including the fuse ends. Since I have done that I have had no issues.

[CoolfinIE]

You can get a new battery for the main starter circuit, but nothing solves sensitivity to voltage brownout quite so permanently as a separate (small) battery circuit for the electronic units.

[SM1]

dido on what coolfin said.

A new battery didnt fix it for me. I had to go with a separate circut. I have had no problems since.

[larrym]

I've got a 102C lowranace and 135 opti. Even with a new battery as I have now my unite shuts off when I start the motor. The last two posts are right on based on my experience. These newer motors take a bunch of cranking power to start.

[PRD1]

Good comment on the power needed to start some of the bigger outboards. A buddy had a new lund (2075?) with a huge Merc outboard (250 HP) and it has 5 batteries; 3 for the 36 volt TM, one to start the outboard and one for accessories in order to isolate the motor from the accessories.

My 70HP Johnson cranks over on very few amps compared to that six foot outboard.

[Backwater Eddy]

We are seeing this a lot, higher demands from starting motor draw, and greater draw from electronics.

I think someplace down the line soon a surge protector or something along those lines may be required to keep both performing well. Possible a dedicated circuit and fuse block for electronics?

A alternator circuit that charges the main staring and electronics battery from the kicker is one option I could see helping. We have ran into this, main battery gets worn down from electronics and live well while running long trolling runs...go to start main engine...not enough juice to kick up the motor.

An alternator maintaining the starting and possibly the trolling motor circuit would be highly beneficial as I see it.

Does anyone know if the add on Min-Kota alternator charger will accomplish this, the new on-board model?

There also is a Voltage Sensitive Trolling Bank Voltage Sensitive Charging Module out that may do this. Anyone have experience with either?

Thanks,

[hondo]

An alternator maintaining the starting and possibly the trolling motor circuit would be highly beneficial as I see it.

Does anyone know if the add on Min-Kota alternator charger will accomplish this, the new on-board model?


The DC alternator chargers or Charge-On-The-Run systems work off the voltage supplied by the motor's alternator, so you're not increasing the output, you're just able to split it between multiple batteries. If the alternator isn't keeping your main battery charged the DC alternator chargers won't give you any benefit.

A high capacity high output starting battery that is at least 1000 cranking amps should be enough to power your electronics, pumps and start your motor. Other accessories like lights and stereos will put a bigger draw on your battery. Having your starting battery connected to an on-board charger to maintain your battery when you're not using the boat is well worth it too imo, it keeps the battery in tip-top shape so it's ready when you hit the water.

One other tip that can help --- if you've been putting a lot of drain on your battery, try turning off your pumps or other accessories a minute or so before you start your motor -- ie. if you know you're going to be firing up the motor to move, turn off your pumps and everything you can except your electronics before you reel in, stow your trolling motor, get everything in the boat stowed away for the ride, etc. It's just a bandaid but it can work.

[VernH]

We are seeing this a lot, higher demands from starting motor draw, and greater draw from electronics.

I think someplace down the line soon a surge protector or something along those lines may be required to keep both performing well. Possible a dedicated circuit and fuse block for electronics?
.
.
.
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There also is a Voltage Sensitive Trolling Bank Voltage Sensitive Charging Module out that may do this. Anyone have experience with either?

Thanks,

Surge protectors typically handle overvoltage conditions. A big capacitor (a battery is kinda like a really, really big capacitor) would even out high demand current draws. The problem here is the long term, all day long continous use of the starting battery to power lots of electronics. With a big motor, a second battery just to power the electronics really is the answer.

The Voltage Sensitive Trolling Bank Voltage Sensitive Charging Module from BEP sold by many is perfect for this situation. I effective did the same thing using two of the big rotating switches seen on the item being discussed when I rewired my boat a while back. The module wasn't available then. My motor postive terminal is attached to both positive terminals on my switches. The other side is attached to the respective plus terminals of each of the two batteries I'm trying to charge. I have a battery voltmeter on my instrument panel and I act as the "module" to determine which battery to charge. My motor, at idle, generates almost 15 amps of charge current so I can keep things topped off as needed. I charge my batteries once in the spring and if I'm pay attention, I usually never have to charge externally again during the season.

When I'm not using the boat, both switches are set to off. That keeps the motor's ECM unit from draining a battery. I can also start from either battery if need be.

A BIG DOWNSIDE is that I ABSOLUTELY must NOT shut both switches to the off position while the motor is running. Most alternators need a load on to prevent the voltage from going to high and blowing the requlator module or other parts. I always turn the next battery to the ON position before I shut the currently charging battery off. There is a zener type product that West Marine used to sell to prevent that, I'm too cheap to buy one. May regret that decision one day. The BEP module should prevent that.

2213

Big motors (and lots of cool electronics) require bigger (or more) batteries.

Multiple, isolated batteries really make the most sense.

Vern

[Backwater Eddy]

Good tips Hondo.

It appears the 250 Merc and the Garmin 5212, and the other miscellaneous toys are competing too much for amps.

We will try to rest method and see it it does it. We have a new 1000 in it now for a starting battery. I'm tempted to add a second rigged to 12V, just for piece of mind.

Thanks,

[Backwater Eddy]

More great tips..thanks again.

The module is kinda the way I'm leaning...and a second battery dedicated to the dash toys.

Thanks,

[TEXAS PIGS]

If you are considering using a second battery for the electronics, where are you going to put it, i have a 1900 pro V 2000 can't see a place to put another. i too have this problem. i even bought a new interstate battery(biggest they make). open to opinion on battery placement. looking to add more electronice toys this winter.

[Backwater Eddy]

Might have to push the battery tray over in the 21 pro V SE a bit, but it looked to use we could shove another in there..with a bit of work. We also got as fresh 1000 cca Interstate in it, and may add the second of the same size or a bit smaller if need be.

I'm thinking the Voltage Sensitive Trolling Bank Voltage Sensitive Charging Module might just be the ticket.I'll talk it over with "Sumo Hunter" when he gets back from his scooter trip to Montana and see what he thinks will work. We both are preaty tired of the jumper cables being "Plan B".

[blueicecpa]

Stealt DC charger added sovled my problem .

http://stealth1charging.com


I run 5 batteries, Starter, House for electronic's and 36v trolling motors.

The Stealth DC has use of the big engine altenator to top off the 4 batteries after the starter is fully charged.

Hondo is right after I installed a TR1 autopilot and upgraded electronic's I could only get 4 hours before everything went haywire. Way too much draw with these new technology's.

[icefisherman]

Similar issue here.
I have one 525 and one 520 connected in network and Ethernet together.
When starting the big motor the 525 shuts down but the 520 stays on?!?
This only started to happen recently.
Maybe my battery is getting old but why this does not affect at all the 520?!?

Cheers,
Ice Fisherman

[PRD1]

My guess is you have one fore and one aft. The one closer to your starting battery is the one that stays on and the one on the bow drops out? As one other post noted any connection issue (poor/loose/corroded connection, corroded fuse holder etc.) will also contribute to the problem if the battery is weak so it is not unusual to have one sonar drop out while the other stays up. Again turn on the voltage monitor on the 520 and 522 and see what the difference is.

Good luck.

[dclelandfishing]

i had the same problem with a 350 lowrance id start my 125 mecuryand the graph would go off,goit a new battery and it still does it once in a while but not as much as before maybe a guy needs the best battery made:cookoo:

[Backwater Eddy]

A question to the electronics guru's out there....Would a capacitor on the line prevent the bleed back and voltage drop that shuts down these units at start up?

[VernH]

A question to the electronics guru's out there....Would a capacitor on the line prevent the bleed back and voltage drop that shuts down these units at start up?

Nope. :sorry:

You're pulling big (100+ amps?) for a few seconds. Cap would have to store all the energy needed to run your electronics for the entire cranking period. Diodes are the equivalent of the one way valve to prevent the "bleed back."

The cap would have to be big enough that at the end of the cranking period, the remaining voltage is still over the shutoff threshold. We're talking many Farads, not the microfarads as you usually see in capacitor values. Also have to have some current limiting circuitry to protect the diode from in rush current needed to charge the big cap. If you limit the current too much, your electronics won't power on right away. Gonna cost you more than another battery.

The problem is the amount of current draw used by all the electronics for extended periods of time draws the main battery being used down to a level that is close to the shut off threshold of the devices. As the battery's voltage goes down, so does the capacitor voltage AND the capacitors voltage would be about .6 Volts less cuz of the isolation diode.

Best option still is another battery. Doesn't have to be a monster battery either. If you have a small lawn tractor battery, try that first. Wouldn't use the ice fishing gel cells. Charge characteristics are too different.

Every now and then I see a small device that is plugged into your cig. lighter socket. They claim you can start your car off the little box. Must have a bunch of NiCads in it. Maybe something like that might work.

Vern

[Smitty]

2 thoughts on my part. First as others have said have your battery tested and make sure it's not getting ready for replacement. If the battery checks out fine, I can only tell you what I did to solve the problem (my Lowrance 332C was doing the same thing). Rather than coming off the fuse panel for juice, I ran 2 heavier (10 guage if I recall) wires directly from the starting battery to a fused connector panel I bought and installed under the console and attached my electronics there. What I found was that by running heavier wire directly to this panel my voltage drop was much lower, and while the voltage does still drop when starting the main engine it stays high enough to avoid having the sonar shut off.

A seperate battery would certainly solve the problem, but like others I don't have a convenient place to store another one and this solution worked for me.

[Hot Runr Guy]

2 thoughts on my part. First as others have said have your battery tested and make sure it's not getting ready for replacement. If the battery checks out fine, I can only tell you what I did to solve the problem (my Lowrance 332C was doing the same thing). Rather than coming off the fuse panel for juice, I ran 2 heavier (10 guage if I recall) wires directly from the starting battery to a fused connector panel I bought and installed under the console and attached my electronics there. What I found was that by running heavier wire directly to this panel my voltage drop was much lower, and while the voltage does still drop when starting the main engine it stays high enough to avoid having the sonar shut off.

A seperate battery would certainly solve the problem, but like others I don't have a convenient place to store another one and this solution worked for me.
excellent advice. As an example, using a 5amp draw, and 10' length of run (1 way), 18 gauge wire has a .658v voltage drop, or 5.48% of loss. Using 10 gauge wire gives a voltage loss of .103v, or .86%. Right off the bat, before the big motor even cranks, the heavier wire is providing more voltage to the unit.
HRG

[VernH]

excellent advice. As an example, using a 5amp draw, and 10' length of run (1 way), 18 gauge wire has a .658v voltage drop, or 5.48% of loss. Using 10 gauge wire gives a voltage loss of .103v, or .86%. Right off the bat, before the big motor even cranks, the heavier wire is providing more voltage to the unit.
HRG

Great answer both of you. Since I run a tiller and my batteries are less than 3 ft away from the electronics I forget that people are making 10-25 ft runs to power their electronics.

Running heavy wire is a good start.

Bottom line is that when we run bilge pumps, aerators, lights, multiple Sonar/GPS units, marine radios, regular radios, big motor ECM, etc. for hours all on a single battery it doesn't take long for the average battery (about 65 amp/hr) to get to a 50% level.

PS. HRG I found out I can't even drive my boat with the big Verado cuz I need to be only 133 lbs or I'm over the weight limit for the boat. Guess trolling speed is the least of my problems.

[Backwater Eddy]

Thanks Vern...ya kinda lost me...but the Nope part sunk in fine. ;)

[VernH]

Thanks Vern...ya kinda lost me...but the Nope part sunk in fine. ;)

Engineers are typically Verbose. :blahblah: Sorry.

Try the heavier gauge wire. Could be all you need...

On one of our annual trips, we've been arguing with one of the guys who refuses to put another battery in his boat (he has the space, money.) He runs absolutely everything, two locators, 40 hp Yamaha 4 stk, electric trolling motor, lights, timed livewell, Q beam and a marine radio off the same battery. We usually can't understand a word he says on his radio cuz of all the interferience.

He rarely uses the electric motor anymore. I think he is afraid to shut the gas motor off cuz it may not start again.

I can't imagine that your conditions are that bad.

Vern

[Backwater Eddy]

I apreciate the explination, most of it sunk in..the rest may in time. Some days I'm a bit slow'r than others....Don't ja know..Eh.

That is what I like about WC.com...folks eager to try to help others build on our mutual knowledge and skill sets.

Thanks Vern!

Ed