Low voltage, gauge variations

[burtonrider11]

Just took out our new to us Powerquest 260 with 454Mag EFI yesterday. Boat starts and runs fantastic. However, I noticed that when running back to the dock, when I turned on the nav lights (green/red and white stern) it dropped my volts low, both on gauge and on my GPS. In addition to that, it seems to affect my gauges as tach, oil pressure, temp, fuel all went up. If I turned the lights off, they went back down. I could repeat this process with the same results. It didnt matter if we were idling or 3500RPM.

There are two batteries with battery switch. It looks like this was wired up to have a starting battery and an accessories battery. Not sure if it ties in with that. One battery was new in 2018 and I'm unsure of the 2nd.

I also noticed that when I was running in the driveway, I could hear a "clicking" sound and the volt meter would drop with each click and then come back up. Click was every 5-10 seconds or so.

My thoughts are that perhaps the alternator has a bad/corroded connection or is bad itself. Perhaps batteries are in need of replacement?

One last piece, I noted that when boat is OFF, I can have the stereo on (deck, amp and 4 speakers) and if I turn on the docking lights, it cuts off the stereo. This makes me think that perhaps a battery is going bad - dropping the volts enough to cut out the stereo when something else draws. But it doesn't make sense as the boat starts perfectly. Definitely appreciate any help here!

 

[Bondo]

Ayuh,..... You have a short to ground in the light circuit,.....

Not the battery or alternator,.....

 

[burtonrider11]

Ayuh,..... You have a short to ground in the light circuit,.....

Not the battery or alternator,.....

Okay, that would make sense. The lights do work when switched on. Would a short still allow the lights to work?

I was thinking that I might start the boat and work thru the accessories to see if I can replicate these occurrences with different accessories IE blower, bilge pump etc.

I'm still concerned about the voltage showing low - 11.8-11.9 volts while running seems low?

 

[Silvertip]

Put a wrench across the battery terminals and the voltage will read low as well (and make a giant spark). The clicking you hear is a circuit breaker (auto-reset type). If clicks off due to the short so voltage goes up because of the now open circuit. When it resets, the short is back again and voltage drops.

 

[burtonrider11]

Put a wrench across the battery terminals and the voltage will read low as well (and make a giant spark). The clicking you hear is a circuit breaker (auto-reset type). If clicks off due to the short so voltage goes up because of the now open circuit. When it resets, the short is back again and voltage drops.

Awesome thank you. I posted this in a Powerquest forum and a bunch of people mentioned that they ran secondary power and grounds up to the dash as the primary wires were too small to carry the load. I'm also going to start swapping light bulbs for LED to help in lowering the amp load thru these.

I went on board last night trying to isolate some things and my initial thoughts are that it is definitely tied to any power running thru the dash. I can run components such as blower and bilge pump with very little voltage drop - this makes sense to me since they are wired to the battery, not taking power thru the switch or service in the dash.

I'm going to open up the dash today to see if I can locate a loose connection or bad ground somewhere. I will most likely be running bigger power and ground wire up to the dash as well.

 

[dingbat]

The first step in trouble shooting an electrical problem is to verify the power source. Have both batteries load tested before you go tearing into things.

You have two different circuits on the boat. The fact that the bilge and blower (typically wired to starting battery) don’t exhibit the same problem leads me to believe the house battery has issues.

What does each battery measure (with volt meter) with the boat running then not running?

Then turn on the problem circuits and measure the voltage on each battery again.

 

[burtonrider11]

The first step in trouble shooting an electrical problem is to verify the power source. Have both batteries load tested before you go tearing into things.

You have two different circuits on the boat. The fact that the bilge and blower (typically wired to starting battery) don’t exhibit the same problem leads me to believe the house battery has issues.

What does each battery measure (with volt meter) with the boat running then not running?

Then turn on the problem circuits and measure the voltage on each battery again.

Great point, that is on my list of things to check. I also have the batteries in my other boat that I can check against the house battery.

As an aside, I haven't had a boat set up with a starting and house system. Should I be starting and running on "ALL" to charge both while underway? Otherwise, it would seem that I would be drawing power from one and not necessarily recharging it. Once anchored up, I would then switch to "house" to save the starting battery for later. Do I have that correct?

 

[Silvertip]

Dual battery switches are the most misunderstood electrical device on a boat yet in very simple terms it is a "traffic cop" for directing current to the battery (charging) and from the battery (powering things). So the key here is 1) install an on-board charger on your boat that keeps batteries topped off when the rig is not in use. 2) Then when underway or anchored, set the switch to the battery you intend to use to operate accessories. Hopefully this is NOT the START battery. When you get ready to up anchor, start the engine and set the switch to the battery that needs the most attention. If you are not drawing power from a battery and it is fully charged to start with, there is no need to charge it because it will, by its design, refuse to accept further charge and quite possibly may gas thus losing electrolyte and shortening it's life.

 

[dingbat]

As an aside, I haven't had a boat set up with a starting and house system. Should I be starting and running on "ALL" to charge both while underway? Otherwise, it would seem that I would be drawing power from one and not necessarily recharging it. Once anchored up, I would then switch to "house" to save the starting battery for later. Do I have that correct?

Dual battery setups with a switch are a pain to maintain.....

Drawing from one and not recharging is only part of the issue.

Few people run a boat long enough to fully change two batteries, leaving you with a larger deficiency each time you go out resulting in a slow spiraling death for your batteries.

The other part is when you put the switch in "Both" the batteries equalize. Your 100% charged stating battery combined with a 25% charges house battery results in two 50% charged batteries. Not good either.

I got tired of the switch game and installed an ACR years back. Turn the switch to ON when I get in the boat. Turn the switch OFF, when I leave. Keeps the "starting" battery fully charged then routes any surplus charge to the house battery automatically.

 

[sam am I]

Dual battery setups with a switch are a pain to maintain.....

Drawing from one and not recharging is only part of the issue.

Few people run a boat long enough to fully change two batteries, leaving you with a larger deficiency each time you go out resulting in a slow spiraling death for your batteries.

The other part is when you put the switch in "Both" the batteries equalize. Your 100% charged stating battery combined with a 25% charges house battery results in two 50% charged batteries. Not good either.

I got tired of the switch game and installed an ACR years back. Turn the switch to ON when I get in the boat. Turn the switch OFF, when I leave. Keeps the "starting" battery fully charged then routes any surplus charge to the house battery automatically.

Total sidebar here but, since it is already being brought up...

I've been always a bit curious about this and I agree but, isn't an ACR just a measured/calibrated (sensed by a threshold/s hard set by the ACR's electronics) way/form of an automatic "both'ing"? It parallels both the batteries together just like the Perko switch, right?

If so, then in either case, manually or automatically, "both'ing" the 100% (12.6V+) batt (which 100% is assumable some where's near the ACR is set to "both") with a 25% (11.66'ish V) batt as in your example, aren't you still ending up with a 50% "not good either" batteries situation but, it's just doing it automatically for you?

So given the above and all things being equal (engine running, alt working, no hard failures and the like), there isn't any electrical advantage in one over the other? Other than one method allows (forces) the drop into the 50% mud zone of both batteries automatically instead of manually?

 

[dingbat]

I've been always a bit curious about this and I agree but, isn't an ACR just a measured/calibrated (sensed by a threshold/s hard set by the ACR's electronics) way/form of an automatic "both'ing"? It parallels both the batteries together just like the Perko switch, right?

Yes and no.

Im running SI feature on mine as well

13.0V for 90 Seconds: If either the B or Aterminals of the ACR sense 13.0V for more than 90 seconds the ACR will close and parallel the batteries. The green arrow is pointing to the relay being closed and the banks are in parallel.

13.6V for 30 Seconds: If either the B or Aterminals of the ACR sense 13.6V for more than 30 seconds the ACR will also close and parallel the batteries. The green arrow is pointing to the relay being closed and the banks are in parallel.

12.75V for 30 Seconds – If either the “A” or “B” terminal sense a voltage below 12.75V for more than 30 seconds the relay will open/un-parallel the batteries.

12.35V for 10 Seconds – If either the “A” or “B” terminal sense a voltage below 12.35V for more than 10 seconds the relay will open/un-parallel the batteries. IF voltage is trending upwards and attains 12.75V before 10 seconds has elapsed the relay will remain closed. This logic is here to enure a large load will not cause the relay to open when it creates a short duration voltage sag. It is also there to help minimize “relay cycling” which we will discuss later.

Start Isolation – The SI feature or “Start Isolation” is a unique feature to the Blue Sea Systems line of ACR’s. The start isolation feature momentarily opens or un-parallels both banks when the starter motor is engaged. The SI terminal of the ACR is wired to the “start position” of the engine switch (see above image) or to the start button. It is never wired to the “run” position. Doing this will keep the relay open indefinitely. Again, we’ve seen this done… When the starter motor is engaged the ACR’s relay opens so any voltage sag is not transferred to the house bank, where a low voltage may cause electronics to shut down. For the SI feature to work as intended you need a dedicated starting battery and a dedicated house bank. The SI feature does not work with a 1/BOTH/2 switch where starting and house loads are shared by the same bank.

16.00V Over-Voltage Lockout – Over-voltage lockout is just what it implies. If the sensed voltage at either the “A” or “B” terminal is 16.00V or higher the ACR will lock out and open itself.

9.50V Under-Voltage Lockout – Under-voltage lockout is just what it implies. If the sensed voltage at either the “A” or “B” terminal is 9.50VV or lower the ACR will lock out and open itself. If you’ve drawn one battery too low don’t expect the ACR to combine until the battery gets back above 9.50V. In a case like this simply use your manual battery switch set to Both or your manual emergency parallel switch.

 

[sam am I]

Not to beat a dead horse here......But, this is a bit of a conundrum,

But still, all in all, it is still just paralleling/both'ing them right? It is just auto "both'ing"/parelling(or not) both batteries together based on all these pre-set values and logical restraints?.

Thus, in your example of 100% and 25%, the/an ACR must still "both'"/parallel (in order to get a charge on the house batt, that's the goal here, right?) just like a Perko switch does? So then, if it's to charge the house batt, "Your 100% charged stating battery combined with a 25% charges house battery". Has to, right? In order to get a charge on it.

Which, then at ACR "both'ing"/paralleling time/s (whenever), we still must have a "results in two 50% charged batteries" but "both'ing/paralleling times with a Perko in "both", which is "Not good either."?

Aren't they the same, when combined?

 

[Silvertip]

Batteries will equalize whether being charged or discharged. On the discharge scenario, when "bothed" the batteries will supply a load and will eventually equallize, even if the load is small. When charging, the 100% battery will not continue to charge because the 50% battery is consuming the bulk of the alternator output. This entire multiple battery thing boils down to what's the absolute best way to do this. Fact is, there isn't one best way. Best way can only be described as whatever is most convenient for you. I consider myself rather techy and dual battery switches have worked for me for years because I use it effectively. On-board charger takes care of at the dock/on the trailer situation. Troller batteries take a beating but I've never had to replace one during the period I owned the boat and I never was left with a dead/fail to start starting battery. On the other hand, if the thought of "my gosh - what setting do I use" make you nuts, then an ACR or some other system may be for you. Even more controversial is using batteries of different sizes in a dual battery system. The alternator doesn't care what size the battery is and when "bothed" the entire system looks like one bigger battery anyway. If that bothers you from a charging perspective, then simply flip the switch to the battery you want to charge.

 

[burtonrider11]

HI all, I wanted to at least post a follow up in the hopes that this may help others. I had posted in the Powerquest forum on Facebook and I learned that PQ, while the boats are very well built, their wiring is not. Many electrical components use power running thru the switched on the dash rather than relays. The best suggest I received was to replace any lightbulbs with LED. So I swapped Nav and Anchor lights, all instrumentation lights and voila! Problem solved. I can run my nav lights and full instrumentation, with next to no voltage drop and no gauge fluctuation. Also the "clicking" sound I was hearing is the hour meter, I believe. THanks again for all the replies.