Red 'CHARGE' light stays on after starting

bradleyheathhays

Registered Member
State
KY
After two summers and a winter of virtually no use I go down to the boat (Hunter 27) to check on things and one of the batteries is showing no voltage on the built in meter right by the battery switch. So I replace it with another deep cycle marine battery and lo and behold both batteries show normal charge now.

So I start the Yanmar diesel engine before I leave to make sure everythings ok and it starts and runs fine but a red light on the control panel next to where you insert the key stays on the whole time the engine is running...about 5 mins. It says 'CHARGE.' I'm assuming this means the batteries aren't charging possibly?

Can anybody tell me what this means and what I need to do to fix this fast?

I wonder if somehow this 'no charge' condition is what lead to the one battery showing no charge on the voltage meter. Possibility?, but I would guess the other battery would have shown no charge as well. I dunno.

Second question is...does my diesel Yanmar engine use any charge from the batteries when it's running? As far as the engine is concerned, is the only time it uses the batteries is when it's starting? If I recall correctly diesel combusts in the cylinder just by compressing it. If this is the case, since my 2 deep cycle marine batteries can crank the engine for a really long time, I could reasonably expect to take a day trip out say if I only needed to start the engine probably twice, even if the charging system was somehow faulty.

To be honest, I'm willing to risk it a little because, well, I got a hot date planned!

If this helps analyzing things here's a pic of my battery wiring. Also, I'm completely sure I got the wiring reattached correctly as I compared to the before picture at least 3 times before starting it. Yes I know it's dirty down there but this hole the batteries are in is so and difficult to get down into.

Thanks for your help.

boat batteries.JPG
 
Last edited:

Putershark

Administrator
Staff member
Lifetime Member
City
Pine Island
State
Florida
Good Morning!
I would...
  • One at a time, remove and clean each battery connection with the battery switch in the "off" position. Some of those wires look rusty and it is the crud that you usually do not see (where it touches the battery posts) that creates the problems.
  • You really need to use a Start battery for "Starting" so you have enough cranking amps to turn over that diesel or any engine for that matter.
  • Check, clean and or simply reinstall the wiring at the battery A/B switch. The use of lock washers if not already in place, will help ensure they do not loosen back up when pound through the waves.
  • Check the connections at the alternator and the alternator belt to make sure they are secure.
  • Check all the ground connections on the engine. Clean and reinstall as needed.
  • If this does not correct the issue, then I would say the Alternator is going south. If possible you can try (just be very careful) while it is running to spray into the Alternator some Electrical Contact Cleaner. Matter of fact I would do that even before starting to help clean up the brushes inside of if that are also getting corroded from setting so much in such a wet environment and not being ran.
  • Lastly I would check on You Tube for "Yanmar Diesel Charge light" and see what shows up?
 

bradleyheathhays

Registered Member
State
KY
Thank you! That's a great flowchart of advice. Just realizing how badly my batt compartment needs to be cleaned up.

My battery switch has 4 settings...Off- Bat A - Bat B - Both bats

I've had other people mention to me the idea of a start battery but how that applies to my setup I'm not sure. I mostly just run it on the Both Batts setting.

As far as eeking out another day trip out of her on just the power that's left in the batteries, others have told me that except for the power it would take to keep a fuel selenoid open the engine would use no battery power after it started. The day trip I'm planning involves running the engine twice, 30 minutes each time. Since the older of my two batteries shows a lower charge my plan would be to start the engine with both batts then switch over to the old battery and do the 30 run across to a cover. After a couple hours I'll start it back up the same way using both batts, switch to the newer battery and do the 30 min cruise back to the dock. I figure if the engine somehow uses more battery power than I'm anticipating, I won't be able to get any further out on the older lower voltage battery than the newer higher voltage battery would be able to bring me back in.

Any ideas on chancing this last trip before fixing the alternator issue?
 

Putershark

Administrator
Staff member
Lifetime Member
City
Pine Island
State
Florida
Most Welcome, and I would never run on Both Batteries, all that does is just kill both if one is weak. I also advise to "never" change the battery switch from one to another while running. You can spike the Alternator or worse from the sudden rush of current.

Depending on the amount of computer controls on the engine will mandate the use of constant current flow. I am just not there to see how that one is made naturally.

End of the day "if" you get her lit off, I would just leave it running to help ensure you can make it back. The only way to help ensure you do not have to resort to such, is to see if you can start that engine on one battery at a time? You can also check the water levels in each one (use distilled water only to refill!) and put them on a overnight plug in battery charger to help get them back to a level needed for operation.

Alternators alone generally do not recharge batteries, they just put back what is being pulled from them. Best example of this... If you have to jump start your truck to get it running and then go drive it some, odds are you are going to have to jump start it "again" if / when you turn it off ;)

Lastly, the Alternator might be fine or just in fair condition at this time, you just cannot "recharge" a defective battery thus the voltage parameters to keep the "charge" light off or in the green are not present. Again, loose and cruddy connection points and create the same problem.

So take the time to get them all the wiring cleaned up, batteries water topped off and recharged and proceed from that point. Much better than getting towed back to port and trust me, if something does fail... It is usually when you need it most like during a storm :oops:

Hope this helps?
Dave
 

Maxg94

Participating Member
Premium Member
City
Middle River
My neighbor fried my old boat batteriy by the positive and negative touching during work. It destroyed the battery fried the battery swich to stay on. After replacing everything he has the same alarm code. Turned out there is a fuse on the engine that also went out to protect the alternator. This was on a Honda ouboard but after he repelaced this master fuse it went off and charged the batteries again.
 
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