Battery questions

LVChris · **Posted:** Mon May 01, 2017 11:09 am

So I am fairly good with electronics, did teletype repair for the US Army and worked fixing TV's and Radio installs when I was younger.

For some reason boat electrical has confused me. Maybe you can answer a few questions.

I went out yesterday and was nervous that my batteries might be going. I plugged into shore power all night with the charger breaker on. That morning I checked, I have a plug in the acc. port that was reporting 8.7 v on one battery and 10.5 on the other. So before I left I hooked up the muffs and started it...it cranked slow but started. Of course when I got to the lake...just clicking.

Boat is a 1996 238 Vista DLX, the po added a third battery so I have one battery on one side of perko, and two on the other.

So Questions

1: Did I make a mistake using the shore power and on board charger? Was I supposed to have the perko switch on?

2. If I got one of those portable jump starters, do you think it would work on this 3 battery system?

3. Should I take each one out and put it on a bench charger, or are they shot and I should just buy new ones?

4. I was convinced by a friend that these cheap O'reillys batteries would be fine since we live in the desert and batteries (even expensive ones) don't last longer than 3 years...was that wrong? (these made it 2 years and 2 months)

5. Being that I never want this to happen again, what is my future self going to do? Buy better batteries, get a good trickle charger, solar? Advice?

TIA,

chris268 · **Posted:** Mon May 01, 2017 12:04 pm

I would say, something isn't working as designed.

I would pull the batteries and take them to O'Reilly's and have them load tested

If one of the 2 in parallel are bad, it will drag the other down with it....

Another thing I would do is measure at the batteries what the voltage is then measure what the voltage is While charging to make sure it's doing the job. Measure all at the battery, there could be a voltage drop at an acc point....

LVChris · **Posted:** Mon May 01, 2017 1:31 pm

thanks Chris, what reading should I be getting at the battery.. I would assume 12v.

Just pulled one battery and put it on my cheapo harbor freight charger. Registering less than 25% so we'll see if this one will take a charge...then move on to the next ones.

At least I think I will be smart enough to never have this happen again. I think I want to get a portable jump starter.

Another question, does anyone really add a lead to the negative terminal of the battery when charging outside of the boat? I am sure it's because you worry about it sparking.

Jdpber · **Posted:** Mon May 01, 2017 2:25 pm

agree i would start out with a load test on all of them. and go from their. too many variables without a solid foundation.

chris268 · **Posted:** Mon May 01, 2017 3:17 pm

LVChris wrote:

thanks Chris, what reading should I be getting at the battery.. I would assume 12v.

I would think closer to 13.6, here is some info
https://www.emarineinc.com/Batteries-Maintenance-101

Just pulled one battery and put it on my cheapo harbor freight charger. Registering less than 25% so we'll see if this one will take a charge...then move on to the next ones.
Get it charged, i would still have a load test done where you bought them

At least I think I will be smart enough to never have this happen again. I think I want to get a portable jump starter.

Another question, does anyone really add a lead to the negative terminal of the battery when charging outside of the boat? I am sure it's because you worry about it sparking.

I never have added lead to the negative terminal

good luck!

LouC · **Posted:** Mon May 01, 2017 3:26 pm

A fully charged battery should be about 12.7 volts, when running with a good alternator and batteries, you should see 14.2 volts. With everything off, try disconnecting the negative terminal and hook up an ammeter in series with the negative post and negative cable. This will tell you if there is voltage draw when the engine is off.

babbot1 · **Joined:** Tue Mar 12, 2013 3:46 pm **Posts:** 570

Sounds like your on board charger is not functioning. Or you lost a cell in one of the batteries. 10 volts sounds like it could be a dropped cell.
Check voltage while the charger is on. Lou pointed out the correct voltages. Some chargers require a fuse between the charger and the battery. I had a dead battery staying over night even with the charger on because one fuse was blown. One battery was charging so the charger didn't indicate any issues. It actually lasted like 2 days before it was low enough to detect.

Start from the beginning and get the batteries tested. You may get a warranty if not too old. Then check the on board charger, then check the voltage while the engine is running.
Good luck.. I seem to always have battery issues too... not just on the boat.

LVChris · **Posted:** Fri May 05, 2017 7:52 am

So just read on another forum that I needed the perko switch ON for the on board charger to work, is that correct?

"OK I have been doing this for 40 years so I think I have it down to a science. The A/B is designed to always give you a charged battery to start your boat. I've always had shore power with an onboard charger and my boat is in a slip with no trailer for five months,so this advice is revolved around that type of set up. When do you leave your boat for the day leave the A/B switch on both so both batteries charge while you are at the dock from the onboard charger. (remember, if you switch it to off your onboard charger will not charge the batteries and all the presets that you have on your boat for example your stereo will turn off and you will have to reset everything)When you are ready to start a fresh day, unplug the shore power first, then start the boat with the switch on both, and leave it on both while the motors are running. Once you arrive at a beach, or a place that you cannot charge the batteries, shut your motor off and switch the A/B to 2. (I have all my accessories, stereo, lights, wired to battery 2) if the boat is sitting uncharged for longer than an hour, I routinely just click my ignition on, look at the gauge and see where I'm at. If I start dipping below 13 V, I switch it over to number one, (that battery has been untouched and has a full charge) start the boat, then switch the A/B switch to both. (I have never seen an A/B switch where you have to pass off to get to either one or two) let the boat run for 10 or so minutes on both so both batteries charge. If you are going to sit for a while, switch it back to the battery you have all your accessories on. Repeat above when you're ready to leave. When you're on your way back home make sure the A/B switch is on both so both are charging from the motor while you are under power. Once you get back to the doc, plug-in the shore power, leave the switch on both and make sure you're on board charger is on and that's how you leave it. I replace my batteries every 2 to 3 years. Make sure you have at least a 900 cranking amp battery's...
The system has worked for me for many years and I have never been stranded on the water without a battery power."

babbot1 · **Joined:** Tue Mar 12, 2013 3:46 pm **Posts:** 570

Many many flaws with what that person stated not sure where to start. Maybe his setup is different from most but from what I have seen. The radio presets are hard wired to the house battery or battery 2 as well as all the bilge pumps. It wouldn't make sense to have those go through a switch and mistakenly turn off and sink the boat.
He is correct about the way the switch works with the engines(he got one correct). The engine will only charge the battery(s) that are selected on the switch.
The on board charger should not need the switch and should charge both batteries even when the switch is off. If it does not then its wired wrong or an odd design.
Running an engine at idle for 10 minutes on 2 batteries is fairly pointless and probably will not charge very much.
2-3 years out of a battery is not very good. 4-5 years is more normal. I usually replace after 4-5 years regardless of condition and re-purpose in a lawn mower or something.
Hope that helps. The best thing to to is get a multi meter tester. They are inexpensive and test the batteries in different situations so you know your own boat.

LVChris · **Posted:** Fri May 05, 2017 12:56 pm

Thanks babbot,

I have a meter but really trying to understand the on-board charger. I plugged my boat in overnight with the PERKO OFF...the panel showed the shore power was on, and the charger was on. However nothing would power on (no cabin lights) if I turned on the microwave breaker, it illuminated...

Just wondering if I need the perko switch on to charge batteries from shore power connection.

babbot1 · **Joined:** Tue Mar 12, 2013 3:46 pm **Posts:** 570

Sounds correct. The cabin lights run off the 12 volt system so if the batteries are off they would not illuminate.
If your charger is factory installed it "should" charge with the perko switch off. Only using the meter to see if you are getting just over 14 volts will tell for sure. If its still around 12.6 volts then you need to do more investigating.
Since your boat is 1996 if you have the factory charger you should look into an upgrade anyways. The new chargers are way better and safer. The one I installed 2 years ago, from recommendation of another member here, is great and wasn't too costly. I installed ProMariner ProNauticP 1220P, I see one on Amazon for $254. I rewired the whole thing from scratch and took maybe 2-3 hours. Its in a bad location tucked under where its not far but hard to reach with 2 hands. I also tried to keep wire runs nice and neat.

EvilZ · **Posted:** Fri May 05, 2017 1:33 pm

If you can see your charger and trace the wires, you should be able to figure out if they go to the Perko switch, or straight to the batteries (which is what I would expect). That will give you an indication of whether or not the Perko switch needs to be on or not to charge the batteries.
My batteries sit in my baking hot boat here in Escondido also, but even the ones I buy at Pep Boys do just fine. Check the fluid levels inside them also if you have access - the charger could have boiled them.

Good luck!

Surface Interval · **Posted:** Sat May 06, 2017 7:24 am

I would add that sometimes the charger wires are connected to the Perko switch on the terminals that the battery leads are connected to. In this instalaltion the battery switch position would not affect battery charger operation.

LVChris · **Posted:** Tue May 09, 2017 12:17 pm

Just to update, took the batteries to Oreillys and had them charged and tested (for free). They said one battery was bad, the other two needed charged. Seems like I am back in business. Still need to figure out why they were so drained.

chris268 · **Posted:** Tue May 09, 2017 8:27 pm

LVChris wrote:

Just to update, took the batteries to Oreillys and had them charged and tested (for free). They said one battery was bad, the other two needed charged. Seems like I am back in business. Still need to figure out why they were so drained.

I do remember reading something about the battery switch needed to be on on the 248 to be able to charge on shore power.... I could be mistaken, I have read a ton over the last 7 plus months on this awesome forum..... the thread was very clear, that the 268 didn't need to, but the 248 did, maybe yours is the same....

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