Battery issues

[GoneFishingLTN]

I have two Interstate AGM 31 series batteries for electronics, one for a Mercury four-stroke 250 engine, and three additional batteries for the trolling motor. I haven’t had any issues with the trolling motor batteries; however, after two or sometimes three hours of fishing, I often experience low voltage on my Humminbird unit at the dash. My Humminbird unit reads 12.6 to 12.4 volts, and my Garmin LiveScope unit at the front stays at 12.2 volts. I also have a Noco four-bank charger set up for the appropriate batteries.

 

EDIT MORE INFO 

 

I never had any warning signs before taking my boat to B.A.S.S. Pro. They told me I needed new batteries, and I agreed(due to age only) I didn’t want to risk power issues during the season. I told them to install the best option, and they put in two Group 31 AGM Interstate batteries.

 

Everything seemed fine at first, but about a month later, I started experiencing a consistent loss of power to the point where I couldn’t even crank the engine. They replaced one of the batteries with the same model, and so far, I haven’t had issues. However, I’m still seeing voltage fluctuations similar to what I experienced when I couldn’t start my motor before. The strange part is that before I ever took it to B.A.S.S. Pro, I never had low-voltage warnings.

 

To make matters worse, in between all of this, they initially wired it incorrectly—running power to the trolling motor from the main motor, which caused electrolysis. They claimed to have fixed that, but now I’m left wondering why these new batteries aren’t performing as expected.

 

If I hadn’t just bought these, I’d switch to lithium, but for now, I need to figure out why my system isn’t working properly when it was before. The only difference is that I previously ran the same battery setup, just not with the Interstate brand.

[Tennessee Boy]

So your Humminbird is giving low voltage warnings while showing 12.4 to 12.6 volts?  What voltage is it showing when you first turn it on?  Is the Humminbird connected to one of the AGM31s or both in parallel?

[GoneFishingLTN]

14 when first on and when motor is running, connected to one but they are connected together parallel I’ll take a pic here

[Tennessee Boy]

Okay so the Humminbird is connected to two parallel batteries that are wired in parallel that are also used to crank the outboard.   Next question.  Are you getting a low voltage warning when you crank the motor?  What model Humminbird?

[GoneFishingLTN]

Only when I crank the motor usually and HumminBird helix 10 gen3

[GoneFishingLTN]

[Jig Man]

I’ve had the exact same issue and spent lots of money with techs and battery dealers.  What I have finally done is buy a lithium 100 ah battery and have run all three of my Solix units to it.  I also bought a single bank 10 amp charger which is wired to the lithium.  It’s been a year now with no issues.

[padlin]

Did I read it right where you only see 12.4 while the motor cranks?

[Tennessee Boy]

Are you sure the batteries are wired in parallel?  There should be heavy gauge wire connecting the + sides of both batteries together and another identical wire connecting the - sides together.  I would connect all of positive (red) load wires to the + side of one battery.  The photo shows the red wires wired this way.  All of the negative (black) load wires should be connected to the - side of the other battery.  The photo shows that this is not how it's wired.  If all of the load wires are connected to one battery and the other battery is wired in parallel it should work and doesn't necessarily explain your problems.  However,  if there is a bad connection in the parallel wires, you could end up running everything off one battery and not know it.

 

This probably won't fix your issue.  If it doesn't I would try using one battery as a dedicated cranking battery and the other as a dedicated electronics battery.  If your batteries are good you should have plenty of battery power to run your electronics for many hours.   Cranking a motor will always cause the voltage to drop.  Some fish finders are more sensitive to this drop than others.  I know many people run a setup like yours with two parallel batteries with good results. The advantage is your motor can charge the batteries running your electronics.

 

I tried running everything off a single cranking battery for several years.  I never depleted the battery but I had a gen 1 Solix that would give low voltage warnings every time I cranked the motor.  I had a Gen 3 Solix that worked great.  I ended up doing like @Jig Man and adding a lithium just for the electronics.

[GoneFishingLTN]

12 minutes ago, Tennessee Boy said:

Are you sure the batteries are wired in parallel?  There should be heavy gauge wire connecting the + sides of both batteries together and another identical wire connecting the - sides together.  I would connect all of positive (red) load wires to the + side of one battery.  The photo shows the red wires wired this way.  All of the negative (black) load wires should be connected to the - side of the other battery.  The photo shows that this is not how it's wired.  If all of the load wires are connected to one battery and the other battery is wired in parallel it should work and doesn't necessarily explain your problems.  However,  if there is a bad connection in the parallel wires, you could end up running everything off one battery and not know it.

 

I'm not sure this will fix your issue.  If it doesn't I would try using one battery as a dedicated cranking battery and the other as a dedicated electronics battery.  If your batteries are good you should have plenty of battery power to run your electronics for many hours.   Cranking a motor will always cause the voltage to drop.  Some fish finders are more sensitive to this drop than others.  I know many people run a setup like yours with two parallel batteries. The advantage is your motor can charge the batteries running your electronics.

 

I tried running everything off a single cranking battery for several years.  I never depleted the battery but I had a gen 1 Solix that would give low voltage warnings every time I cranked the motor.  I had a Gen 3 Solix that worked great.  I ended up doing like @Jig Man and adding a lithium just for the electronics.

First off thank you all I’m not very good with this stuff and have paid a lot and they say it’s fixed until I get on the water and experience the same issue when I turn off the motor I get the low voltage but then my system reads around 14 volts. 

[padlin]

If it were me I’d move the negative’s to the other battery as mentioned above as a first step. I’d also check all the cables for a loose connector.

 

 

[TnRiver46]

I would read voltage with a multimeter instead of on the graph, my graph always reads way lower than the actual voltage

[Jig Man]

This was an issue for me when I had Lowrance units.  When I changed to Humminbird they were the same.  I at first added an Optima blue top just for the 2 bow Solix units.  After 11 months it was grave yard dead.  It was replaced under warranty.  The distributor wanted me to try an Interstate.  In another 11 months it died.  He replaced it and said that if I didn’t use 2 batteries for the Humminbirds he would no longer honor my warranty.  The two lasted long enough to be out of warranty when they died.  
 

I changed brands to Pro Guide and saw the same issue.  Two weeks out of warranty and dead.  My electronics guys recommended that I bite the bullet and get lithium.  I decided to go with Pro Guide and they took into consideration the age of my core exchange and gave me a $300 credit off the lithium.  It was a long frustrating road but I think it may be over.

[GoneFishingLTN]

1 hour ago, TnRiver46 said:

I would read voltage with a multimeter instead of on the graph, my graph always reads way lower than the actual voltage

Went home tested both agm and they read 100 percent charged (which I though was odd) while trolling motors where at 60 due to the high winds I’m guessing. 
 

at 100 percent the agm was reading 12.6 if I remember correctly 

[casts_by_fly]

So if I'm reading you correctly, you have two lead batteries that are in parallel which supply both the big motor and the electronics?  Correct?

 

You say you have one battery for garmin and one for HBird.  But you say that the two group 31 are in parallel and also connected to the motor?  is that correct?

 

13 hours ago, GoneFishingLTN said:

14 when first on and when motor is running, connected to one but they are connected together parallel I’ll take a pic here

 

When you have the big motor running it will show 14V.  That's the alternator output on the motor, not what's in the battery itself.  The alternator outputs at a higher voltage than nominal 12V because that's how you charge.  

 

13 hours ago, GoneFishingLTN said:

Only when I crank the motor usually and HumminBird helix 10 gen3

 

When you crank the motor over, you're drawing power from the battery and the battery voltage will dip as you're seeing.  When you stop cranking the voltage should recover (if the motor isn't running).  

 

You have a 4 bank charger, but you've desribed 5 batteries?  Three for the 36V trolling motor and 2 group 31 (one of which is connected to the 250HP, but in reality both are since they are in parallel).  What are the 4 'banks' each charging?  Presumably one bank on each trolling motor battery and one bank charging the 12V 'system' of 2x group 31 in parallel?  is the bank on the group 31's connected with one cable to each battery or both on the same battery?

 

54 minutes ago, GoneFishingLTN said:

Went home tested both agm and they read 100 percent charged (which I though was odd) while trolling motors where at 60 due to the high winds I’m guessing. 
 

at 100 percent the agm was reading 12.6 if I remember correctly 

 

That isn't surprising if both AGM are connected to the big motor and you were running the big motor a bit.  It would have kept them charged up through the day and on the run back to the dock.

 

12.6 is nominal full voltage on a lead battery, so nothing abnormal there.

 

[GoneFishingLTN]

39 minutes ago, casts_by_fly said:

So if I'm reading you correctly, you have two lead batteries that are in parallel which supply both the big motor and the electronics?  Correct?

yes they are ran parallel so i guess it would be drawing from both 

39 minutes ago, casts_by_fly said:

 

You say you have one battery for garmin and one for HBird.  But you say that the two group 31 are in parallel and also connected to the motor?  is that correct?

 

 

When you have the big motor running it will show 14V.  That's the alternator output on the motor, not what's in the battery itself.  The alternator outputs at a higher voltage than nominal 12V because that's how you charge.  

 

 

When you crank the motor over, you're drawing power from the battery and the battery voltage will dip as you're seeing.  When you stop cranking the voltage should recover (if the motor isn't running).  

it stays at 12.2 after I turn off the motor 

39 minutes ago, casts_by_fly said:

 

You have a 4 bank charger, but you've desribed 5 batteries?  Three for the 36V trolling motor and 2 group 31 (one of which is connected to the 250HP, but in reality both are since they are in parallel).  What are the 4 'banks' each charging?  Presumably one bank on each trolling motor battery and one bank charging the 12V 'system' of 2x group 31 in parallel?  is the bank on the group 31's connected with one cable to each battery or both on the same battery?

 

three for the 36 trolling motor and one to the parallel 31 group agm 

i believe it would just be on one battery since the one in the back only has two thick cords 

39 minutes ago, casts_by_fly said:

 

That isn't surprising if both AGM are connected to the big motor and you were running the big motor a bit.  It would have kept them charged up through the day and on the run back to the dock.

 

12.6 is nominal full voltage on a lead battery, so nothing abnormal there.

 

Also want to add sometimes my HumminBird helix 10 gen3 sides can/down/2d sorta lags then goes back I’m assuming that isn’t common

[casts_by_fly]

1 hour ago, GoneFishingLTN said:

yes they are ran parallel so i guess it would be drawing from both 

it stays at 12.2 after I turn off the motor 

three for the 36 trolling motor and one to the parallel 31 group agm 

i believe it would just be on one battery since the one in the back only has two thick cords 

Also want to add sometimes my HumminBird helix 10 gen3 sides can/down/2d sorta lags then goes back I’m assuming that isn’t common

 

So a helix 10 and a LVS32/34/blackbox/10" headunit will combine for about 5-6 amps.  A group 31 AGM is about 100 AH.  Since you have two in parallel, you've got about 200 AH capacity which should be WAY more than you'd ever need.  That said, 12.2V is around 65% full.  I'm thinking there are a couple things in play here.

 

1- the connections sound like they are all on one battery with the second battery in parallel off the back, as opposed to both in parallel but with a primary connection on each battery.  What is happening is that you're working the battery that the main connections are on a lot harder than the second one backing it up.  Long term, I'd swap one of the terminals if you can so that they are drawing through both batteries the same, if for no other reason than evening out the wear on the two.  If the Humminbird is connected to the 'primary' battery in your setup and the Garmin to the backup (for lack of a better term), that could explain why the HBird fluctuates so much and the garmin doesn't. To that end, for the next trip out I would separate the batteries and run one as a dedicated electronics battery to see if that solves your issue.  It should be a simple swap and easy to test.

 

2- It could also be that the units have different sensors and processing of the voltage sensor readings.  So the same battery might show differently on each unit.  Similarly, the voltage at the terminals won't be the same as at the unit due to losses in the wires between the two. A long skinny wire (humminbird helix power cables for instance) will drop move voltage than a short fat wire.  If you have both on the same battery and no motor/alternator playing with voltage, then you can get a gauge on how they are vs each other.

 

3- Maybe most importantly, you're getting a low voltage alarm but has the unit every shut down or given problems?  The min voltage spec is 10.8V.  Do you just have your low voltage alarm set at a high number that doesn't make any real difference in use? 

[GoneFishingLTN]

24 minutes ago, casts_by_fly said:

 

So a helix 10 and a LVS32/34/blackbox/10" headunit will combine for about 5-6 amps.  A group 31 AGM is about 100 AH.  Since you have two in parallel, you've got about 200 AH capacity which should be WAY more than you'd ever need.  That said, 12.2V is around 65% full.  I'm thinking there are a couple things in play here.

 

1- the connections sound like they are all on one battery with the second battery in parallel off the back, as opposed to both in parallel but with a primary connection on each battery.  What is happening is that you're working the battery that the main connections are on a lot harder than the second one backing it up.  Long term, I'd swap one of the terminals if you can so that they are drawing through both batteries the same, if for no other reason than evening out the wear on the two.  If the Humminbird is connected to the 'primary' battery in your setup and the Garmin to the backup (for lack of a better term), that could explain why the HBird fluctuates so much and the garmin doesn't. To that end, for the next trip out I would separate the batteries and run one as a dedicated electronics battery to see if that solves your issue.  It should be a simple swap and easy to test.

 

2- It could also be that the units have different sensors and processing of the voltage sensor readings.  So the same battery might show differently on each unit.  Similarly, the voltage at the terminals won't be the same as at the unit due to losses in the wires between the two. A long skinny wire (humminbird helix power cables for instance) will drop move voltage than a short fat wire.  If you have both on the same battery and no motor/alternator playing with voltage, then you can get a gauge on how they are vs each other.

 

3- Maybe most importantly, you're getting a low voltage alarm but has the unit every shut down or given problems?  The min voltage spec is 10.8V.  Do you just have your low voltage alarm set at a high number that doesn't make any real difference in use? 

How exactly should I do step one?

 

step 3 I have it set at 11 volts 

[Tennessee Boy]

42 minutes ago, GoneFishingLTN said:

step 3 I have it set at 11 volts 

I think we have the answer!!

 

I would drop it to 9 volts and fish until you see some other problem.   You might want to take one of those cheap portable battery jumpers to jump start the motor so you can get  home if I’m wrong.😊