Need Insight On Electrical Issue

[monzster]

I know this is long but wanted to be specific as possible. I am mechanically inclined but not so much in the electrical field though I can do basic installation of wiring and have knowledge of how to use a multimeter. Any insight at all would be greatly appreciated. I just want to cover as many bases as possible and perform any tests that I can before getting the boat on the water again. Id hate to get stranded. Thanks in advance.

I got this 14 foot jon boat 2 years ago. I installed 2 deep cycle batteries. One from Autozone and one from BassPro. I do not know the specs on the batteries. The batteries are in the front and have them in sequence meaning wired positive to positive and same with negative from there I have run from one of the batteries 4 gauge wiring to 2 Minn Kota Endura C2 30 trolling motors using 2 - 50 amp 6 gauge quick disconnects at both motors everything is soldered together. I also had a 12 volt percentage gauge at the motors that is removable with crimped connectors and ran a Garmin 4 off this same wire. I have had no issues with the boat and had it out maybe 10 times. On my percentage gauge I never got under 90% running both motors during a 3 - 5 hour fishing trip around the reservoir. During a trip last year I lost a motor in the water but was able to retrieve it. I got it home and thought I had gotten all the water out of it by turning it upside down and letting it air out. This was suggested by Minn Kota. Second to the last trip of the year I noticed that the bearing was noisy so I got a new bearing and installed it and totally dried everything. Last trip of the year had no issues.

Over the winter year I installed a 18 watt led flood light, 12 volt 40 amp rated 4 gang rocker switch box that is fused at each switch, 2 universal 12 volt power outlets, led navigation lights, a removable live well with a timer and using 2 pin waterproof 9 awg electrical connectors in places where I wanted to disconnect items in case they went bad, 12-48 volt kill switch rated at 275 amps, a portable live well with timer on the well(which I have not used as of yet), 16 awg wiring used for wiring accessories. All of the items used were China made from Amazon and all soldered.
On the first trip out this year I noticed right off the bat that my percentage gauge was reading 70% with both motors and by the voltage reading on the Garmin 12 volts the whole time. Never had any issues. I ordered another percentage gauge just like the one I had before thinking it was the gauge. When I got home I put my charger maintainer on the batteries and the reading before charging was 11.5 volts. I had the batteries tested after fully charging and both are ok.

Second trip out right off the bat the percentage was 60% with one one motor and with both 50% and the voltage with both was 11.8 at the Garmin. I carried a new percentage gauge with me and installed it but it read the same. I got out in the middle of the reservoir and everything shut off. I cut the kill switch off then back on and still nothing. I checked the relays to the motors which are 50 amp relays and both had kicked out. I cut off the kill switch reset the relays and had power to everything. So while making my way around on one motor I got to thinking why would everything quit? I can see the motors but why would the rocker panel switch quit? So I decided to try a few things while on the water. I disconnected each motor individually and checked the percentage gauge and both were the same with the rocker panel switch on and off. Each dropped to 70%. When the motors are out of the water both running together or individually the percentage is 90% and I am assuming because there is no resistance from being in the water or pushing the boat. So what ever changes I make or do I will have to test the boat in the water. Does this make sence? I made my way around on one motor but the percentage gauge at the end of the day was 40% but coming in I was into the wind which had picked up considerably sometimes pushing the boat backwards. I got home and put my charger / maintainer on and the battery was at 11.5 and by evening they were fully charged. I decided to wire the kill switch differently thinking this was the only thing that would shut off everything. In doing this I noticed that it had wrote on the switch "ignition protection". Upon inspection of the switch I do not see a "reset" unless it is built in. Either way I swapped the wiring to the motors to where they are not run thru the kill switch as the power and motor are on the inputs side of the switch and the only thing run thru the switch now is the accessories which goes to the rocker switch panel. Garmin, navi lights, flood light, power outlets and live well. I did this in thinking it would rule out a bad kill switch even though it is rated at 275 amps. Next time out I will see if it makes a difference.

 

[DaleH]

Stated - Year 1 = 90% readings .... Year 2 = 1st trip, percentage gauge reading 70% ... 2nd trip, percentage gauge reading 60%

BATTERIES - OK, you say your batteries are OK, but are they? How are you testing ... voltage, specific gravity or just via the 'charged' idiot light (no offense to you) on the maintainer? And keep in mind, a 'maintainer' and a true battery charger are quite 2 different animals; the charger being vastly superior to ... in fact actually 'charge' the batteries. If wet cells, specific gravity of the electrolyte is the superior test method. But after any battery charging, you need to wait typically ~24-hours for the surface charge to dissipate, or else you get a FALSE, high voltage reading.

Now I don't use my trolling motor battery much, but you might be drawing down so low as to make it irrecoverable from even a good charging regimen. See the photo. One can permanently damage a battery by drawing it down too low, too deep a discharge. You might think you have a good battery, but again ... you could be getting a false reading by checking it as soon as it is off charge and if the voltage is down to 12.4 or so a day later, then those cells could be sulfated and they will NEVER recover.

Can you borrow a good/known battery from a friend to check it out with? Just tie it in and put through your percentage gizmo gauge. Or take them to your local auto parts place that offers battery load testing for free.

WIRING - If batteries indeed check 'OK', then what about the wiring? Are any of the runs to/from the motors getting warm? Corrosion = resistance and that builds heat, reduces ampacity and blows fuses or circuit breakers. I'd check ALL of your wiring by resistance checks. Also clean all terminals. I first would have guessed the problems were due to the 'wet motor', pulling in too many amps due to some corroded terminal, yet you say they both subsequently tested the same. Where they hooked up the same?

Otherwise the items you added didn't add too many amps and it's not like you'd have them all on at the same time anyway, e.g., 18-watt flood, where (Watts / Voltage = Amps), or 18 / 12.6 nominal VDC = 1-1/2 amps ... then < 1 amp for LEDs, say maybe 5 - 8 amps for the pump; but not sure about the timer. But 16 AWG is also too light (IMHO) for wiring to 12V Accessory sockets, not too much ampacity in that size.

....

 

[GTS225]

Another good question to ask you is; Did you allow the batteries to be subjected to cold or freezing temps? Extreme thermal cycling will shorten battery life, too. Gotta take them into a heated space in the winter.

Roger

 

[monzster]

Thanks for chiming in DaleH. I checked the batteries with a digital load tester from Ebay but it was right after I pulled the charger / maintainer off. I had not thought about checking the specific gravity in the batteries. I will pick up a tester for that this weekend and remove the charger for a day and load test them again. I did not know this. Would I check the specific gravity after they have sat for 24 hours also? The charger /maintainer I am using is from Harbor Freight it is a Viking 4 amp automatically microprocessor controlled battery charger / maintainer and it stays on the batteries all the time when not in use. I do have a friend that has a bass boat that I might be able to borrow batteries from. He is on vacation at the moment but definitely will look into that also.
When on the boat last time when the relays "popped" I did check the main wire going to the switch and to each motor for heat and both felt fine even the smaller original wires going to the motors were ok. I forgot that I had done that in my "off shore testing". The motors are connected exactly the same using the exact same connectors. I am pretty sure the wiring is ok but with that being said I will recheck it this weekend with a mulitmeter.
You say that 16 awg might be to light for for the power outlets. Could you recommend a gauge that you think would be sufficient. I might just rewire the system with that gauge wire if I do happen to find an issue with the wiring. Thanks for the charging chart. Would I use this chart after the battery is load tested or after the batteries have set for 24 hours before load testing? You have given me alot more to go on and I appreciate it alot. This is exactly what I was looking for. I have a pretty big honey do list for the weekend but will definitely get back with my findings. Thanks again

 

[monzster]

Hey GTS225 the batteries do stay in the boat all winter under a cover I live in Va it has gotten into the high 20s past couple of years in the winter. I dont know if it makes a difference but I do keep the charger / maintainer on them all year when not in use. If I do find the batteries are bad I guess the next set I should bring in the house in the winter and keep them on a maintainer I am going to be ignorant here but is this because it is a deep cycle battery and not a normal car battery. The reason I ask is because I have a car that has a deep cycle battery in it that sits alot with an identical charger / maintainer mentioned in my comment to DaleH. Thanks for the input.

 

[DaleH]

Yes, I do wait a day before checking the status of my batteries.

Ampacity of your accessory outlets should be sized to the maximum anticipated draw, plus allowing for overhead. Switching to 14 AWG for those circuits boosts you to 20 amps, vs 10 you have, at 3% voltage drop (critical circuits). See more info here: https://forum.tinboats.net/viewtopic.php?f=3&t=48108&p=478146&hilit=Ampacity#p478146 , plus an ‘ampacity’ chart.

To use, remember to DOUBLE the distance from the power (switch panel or buss) to the load (your socket).

Some believe trickle charge or maintainers can ‘kill’ a battery. And some articles see the need to ‘charge’ using at least 8-10 amps. I bring them inside or to warmer (temps above freezing) in the Fall and charge them using a 10-amp charger, then I charge them again in the Spring - done! I personally seen no use or reason to keep a battery continuously plugged into a maintainer ... at least has worked for me for 40-years +. But, I will readily admit, I do have my biases ...

 

[user 26281]

When you say you have a percent of charge gauge, does it have a shunt in the (-) circuit, wired to the gauge and programmed for the battery or do you have a volt meter that just displays a % based on voltage.

The first type of gauge is pretty accurate, the second type of gauge, depends on the accuracy of the volt meter and resting state of the battery or the percentages can be off. Only .5 volts difference between a fully charged battery and one that is at 50%.

If I understand, you have 2 different batteries hooked in parallel, this is generally not recommended. Parallel batteries should be identical and have very close manufacturing dates.

Do you charge the batteries in parallel or disconnect them and charge separately? Different batteries being charged in parallel can be an issue.

The previous post are right on, use a specific gravity testers to determine the true condition of the battery, you may also want to have them load test. High internal resistance on lead acid batteries can e missed when checking with a multimeter.

 

[monzster]

InSaneFisherMan I do not know if the gauge has a shunt in the negative circuit. I only paid $10.00 for it from Amazon. It has a button I can push that changes it from volts to %. That's about all I could tell you about the gauge. I did not know about the wiring of the batteries in parallel not being good. I did buy them at the same time but had to get different ones because at the time each place only had one in stock. Also I do not know if they are the same amps, model or what ever you would call it (sorry not sure of the word I'm looking for). So it sounds like I really should be wiring the boat one battery for each motor. I had though of this when I started this project but wanted to save money on the 4 gauge wire. It sounds like I might want to start from scratch. I do charge the batteries in parallel and I do not disconnect them from the rest of the boat. I picked up a specific gravity tester last night and am going test the batteries this week end after they set off the maintainer as DaleH suggested. I appreciate the input. This is great stuff. Kind of wished I had asked this stuff before wiring this boat. Live and Learn as they say.

 

[user 26281]

You can connect batteries in parallel and I would not rewire. The next time you replace batteries, I would try to match them.

Here is a link that discusses mixing batteries.

https://batteryguy.com/kb/knowledge-base/connecting-batteries-in-parallel/

The same goes for charging, one battery will charge more/less than the other.

The meter you have appears to be a volt meter, uses the voltage to determine capacity. For example, my inexpensive volt meter in my boat shows 13vdc, my multimeter 12.6. Although theses gauges are a good source of information if they are not accurate, determining capacity is difficult.

 

[DaleH]

That's the intent here about the 'health' of a battery, whereas the specific gravity test tells if fully charged and a load test tells if good enough to hold and deliver the amps.

With a battery where the plates are sulfated, and thus compromised, the remaining plates may charge and read ~12.6 volts or so ... leaving you to think it is 'OK', but there's no oooooomph, power or amps behind that voltage. Get it?

With DC circuits I think of it like this; comparing electrical ions to water, sort of. Where Voltage is like Temperature of the water (ignore that yes, extreme temps at either end can kill you) and Amps = the Flow or Pressure; that's why it is the amps that gets you. Stick a metal wrench (... but please do NOT do this!) across both terminals of a battery and you instantly dump ALL the amps available into the metal and essentially make an arc welding tool! Whereas otherwise the 'temperature' of a 12 Volt circuit is ... meh, nothing much to worry about.

 

[monzster]

InSaneFisherman thanks for that battery link. Very interesting reading. Yesterday at lunch I took the batteries off the charger / maintainer. I got me a specific gravity tester and will check that after work this evening and load test them and depending on my finding will go from there. With what I have learned here I may go a different approach with things. My best friend who goes fishing with me from time to time has been wanting me to put one of my trolling motors at the front of the boat. If my batteries test ok I may end up doing this and then designating a battery for its own motor and not running them in parallel and having a charger / maintainer for each battery. If I do end up going this route I am also thinking of possibly buying a deep cycle "kayak battery" and upgrading the accessory wiring to 12 awg wiring and using that to power my accessories. In upgrading the accessory wiring I am seeing copper stand wiring which I used when I ran the 16 awg for the accessories but I am also seeing what is called marine tinned copper wire. From what I am reading I should have used this instead of copper from the get go. So depending on my battery results I have alot to think about. Again thanks for the help and advice. I will let you know my finding after testing the batteries.

 

[MrGiggles]

Well, the first thing I see is that you are running two batteries of different specs in parallel, and also charging them the same way. That could be the source of your problems, one of your batteries is likely marginal and sucking up all the charging current, and also pulling the other down.

Batteries connected in parallel will equalize, if you connect a dead battery to one that's fully charged, you'll end up with two at 50%. That is why it's important to only run batteries in parallel that are of the same age, manufacturer, and capacity, so they discharge equally and aren't as likely to run each other down.

It is also important to charge them individually when possible, an onboard charger that has a bank for every battery is a worthwhile investment. Set it and forget it.

I fish all year, my boat (and the batteries) sit outside all winter. As long as they're fully charged up, it's no problem. Dead batteries will freeze though.

 

[monzster]

So here are my findings. Both batteries are of a 27 series but I cannot see the specs without removing the batteries and it was about to pour rain and with them being different manufactures I didn't see the need to pull them from the information I have received here.
The batteries sat for 29 hours without the charger / maintainer but still connected to the motors. I disconnected the batteries and all wiring and checked the specific gravity and they all show good with a EZRED hydrometer. With that the #s were 1265 on all except for on each battery the cell closest to the positive post read 1275. I load tested each battery with my Ebay digital tester, brand name DLG that puts a 80 amp load for 10 seconds and its shows good on both. So at this time Im thinking Im good in the battery department.
So before I start to think about moving a motor to the front and checking the wiring, possibly rewiring, which I am 95% sure is ok (gotta leave that 5% open for human error). Is there a way for me to check the motors out of the water to rule out the motors themselves. Would it do any good to put them in a trashcan full of water and would it be beneficial for me to get an amp gauge instead of a percentage gauge for testing / monitoring if a trashcan full of water would even show me anything. At least it will be nice this weekend so I can get this done.

 

[MrGiggles]

So here are my findings. Both batteries are of a 27 series but I cannot see the specs without removing the batteries and it was about to pour rain and with them being different manufactures I didn't see the need to pull them from the information I have received here.
The batteries sat for 29 hours without the charger / maintainer but still connected to the motors. I disconnected the batteries and all wiring and checked the specific gravity and they all show good with a EZRED hydrometer. With that the #s were 1265 on all except for on each battery the cell closest to the positive post read 1275. I load tested each battery with my Ebay digital tester, brand name DLG that puts a 80 amp load for 10 seconds and its shows good on both. So at this time Im thinking Im good in the battery department.
So before I start to think about moving a motor to the front and checking the wiring, possibly rewiring, which I am 95% sure is ok (gotta leave that 5% open for human error). Is there a way for me to check the motors out of the water to rule out the motors themselves. Would it do any good to put them in a trashcan full of water and would it be beneficial for me to get an amp gauge instead of a percentage gauge for testing / monitoring if a trashcan full of water would even show me anything. At least it will be nice this weekend so I can get this done.

Just being 27 series doesn't mean much. They really need to be as close to an exact match or you're shooting yourself in the foot.

About all you can do with the trolling motors is check their current consumption with a clamp meter. Running in a barrel should get you closer to actual running conditions. I don't think running them unloaded will tell you much.

You'll need a DC clamp meter, be sure to check before you buy since the vast majority are AC only.

For what it's worth, almost every time I've run across issues like this, it was a battery. They can fail in just about any way you could imagine, and they aren't made very well anymore.

 

[user 26281]

All the previous post seem spot on.

Seems like all your testing of the batteries are good, a few thoughts on the battery gauge.

I think it is volt meter with a built in calculator for displaying percent of charge.

When using a volt meter to calculate percent of charge, the battery must be resting, basically not being used. Otherwise you will see a drop in % because of the load put on the battery. I suspect the gauge you have is the same.

I could not tell from the original post if you were using the motors when getting the drops in %. If you were using the motors, those readings (%) are probably incorrect.

When you test your motors, I would only pay attention to the %, when motors are off.

 

[monzster]

MrGiggles I didn't think both batteries being the same series would make much difference from what has been suggested here but just thought I would throw it out there. InSanefisherMan when I was on the water and the batteries are in a rested state the % does come back up to like 80 - 90 % its when they are in use that the % drops so much. Before I did the wiring of the boat, adding the lights, rocker switch panel, ect... my % never dropped below 90% even when running both motors. Maybe its just the batteries being older now but having the relays kick out has been my major concern. Im lazy and dont like to paddle, LOL. I think my next plan of attack is to try running the motors in a trashcan possibly just to see if I can make anything of it. I did find out that my multimeter has an amp clamp so that might come in handy. Then I will move one motor to the front of the boat and dedicate a battery to each motor, wire my Garmin and eliminate everything else for the time being and see what kind of readings I get from there. I have a pretty big honey do list this weekend so dont know if I will get to post anything but will keep you posted of my findings and how things work out. I just want to say thanks for all the info I have received so far. Definitely have learned alot. Ill have to gather up some photos of my boat and changes I have made. That was the main reason for joining this group was to get some ideas of what direction I wanted to go with it. Maybe someone will get some ideas from mine and maybe a good laugh. Im a poor man so sometimes I have to improvise. Again, thanks alot.

 

[DaleH]

Did you ever compare what size cables to the trolling motors you are using - for their length - versus that which the trolling motor maker advises? Or even compare to that ampacity chart I posted? Otherwise I'm afraid I'm out of ideas, but yes, the barrel trick should suffice to load the motor.

Not just for wiring, but sometimes people configure things where it 'all works when all is new', but then it may not have the sufficient overhead or capacity to function properly over time. I've even experienced this with manufacturing systems in a production environment, I use to say 'the design was operating on the hairy edge' between success or failure, everything had to be 'optimal' for it to work.

 

[monzster]

DaleH the cable I used going to the motors from the batteries I believe I used a graph that was posted from Minn Kota for the length boat I have or I may have Googled it. I cant remember. By the chart you posted even with the accessories added I think I am still ok. I do think for my accessories it does look like I am under gauged in that so I think I will upgrade there and doing some continuity testing on the accessories. Oh I found out that my multimeter actually came with an amp clamp so I might put that to use. I always say just cause its new doesnt mean its right. I ran into that years ago working on cars. One time I got a new Honda distributor cap from the dealer when tuning up my car for regular maintenance and after starting it was missing on a cylinder. Upon checking things out it turned out that when the cap was made the brass electrode i guess you would call it was totally missing in the cap where the spark plug wire went, so you never know. Im hoping to check it out more this weekend. Im starting to think its simple and right there and when I find it its gona be like "well dang". It might take me some doing. Mechanical is one thing. Electrical Im a little shady there, LOL

 

[old_fart]

Another good question to ask you is; Did you allow the batteries to be subjected to cold or freezing temps? Extreme thermal cycling will shorten battery life, too. Gotta take them into a heated space in the winter.
Roger

I'd disagree with that to the point where I'd charge them in the fall and stick 'em in the freezer.
(Wifey might object :roll: ) but the point being a good battery won't freeze in the lower 48 and
leaving it sit all winter in the warm will degrade it faster than the cold... Leaving it on a trickle
all winter is also problematic...

Clean the top of the battery off, fully charge it, and leave it in the cold.

-W

 

[user 26281]

I believe what you are seeing on you battery gauge is correct and will drop when in use and show the proper capacity when the batteries are rested.

Proper battery maintenance and charging will prolong the life of your batteries. Lot of good advice here and on the web.

Now, if I understand you have two 50 amp circuit breakers installed and they both reset. How are the breakers wired and how were you using them when they reset? Does this reset happen regularly?

I would not expect a 50a cb to reset, under normal use and if wired properly. Generally it should only reset if you get into weeds or something stops/slows the prop.