Red 'CHARGE' light stays on after starting

[Heath2]

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.

[ttex]

I am by no means an expert but I am thinking it has to do with your alternator charging the batteries.

No idea why you would only notice it now.

[Wotname]

Originally Posted by Heath2

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?


Correct! It means the alternator is not producing any output. There are various reasons for that. It could be a failed alternator drive belt, a wiring or connector fault or a faulty alternator.

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?

Correct!

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.

Yes, you should get many (dozens) starts out of a fully charged battery for your little Yanmar diesel.

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.

Comments in blue!

[Sailmonkey]

Have you revved the engine? If it’s been a while since the engine was run the alternator may need a bit of persuasion to start charging.

[CaptTom]

Wotname's got it. That light shows your charging system is not working. And, as long as you run NO other electrical "stuff," you should get a number of starts out of it.

That said, those batteries should be (1) strapped down, (2) in a battery case, and (3) covered, or at least, have the positive terminals covered.

It would suck to get boarded and have them find a violation on your hot date! (Good luck, BTW!)

[NYSail]

Use your meter and check it the alt is charging. Also check all connections (with engine off!) coming from alternator. Remove clean and reattach.
A hot date turns real cold when the boat malfunctions when out on the water!

[Spot]

I agree with SM that revving it a little may change the indicator light. I converted a farm tractor from generator to alternator and added an 'idiot light' that let the operator know if the field of the alternator was draining the battery if the tractor was idling or off. If the tractor was to be shut down a switch was flipped to break the connection which doused the light.

It does looks ripe for a boat improvement project: pick up loose objects, vacuum hold, label wires, clean batteries and terminals, put batteries in boxes with covers and strap them down. If you are not going to do that at least make sure there is no loose metal in the hold to short the batteries (like the Vise-Grips) and they are not going to slide around stressing the connections.

I cannot see + or - signs on the battery with the heavier red and black wires. Assuming that the short blue heavy wire is - to -.

Where does the long blue wire go?

I once saved my RV by having a similar setup where I could jumper cable the separate batteries for an emergency start boost. It was not worth putting in a battery selector switch for as often as I needed to try it.

PS I see some other posts came in. Yes, a USCG boarding or a major systems failure might not impress your companion...

[Group9]

Usually, when that happens to me, it's a loose fan belt, and the alternator isn't turning fast enough, due to slippage.

That's what you hope it is, anyway.

[CaptTom]

Originally Posted by Sailmonkey

Have you revved the engine? If it’s been a while since the engine was run the alternator may need a bit of persuasion to start charging.

Originally Posted by Group9

Usually, when that happens to me, it's a loose fan belt, and the alternator isn't turning fast enough, due to slippage.

Yeah, good points. Those are the first two things to check. Hoping it's that simple!

[steve0h]

YIKES!! STOP PUTTING SEAWATER DRIPPING STUFF ON YOUR VENTED LEAD ACID BATTERIES!!
CHLORINE GAS IS THE RESULT, VERY NASTY WAY TO DIE!


Sorry for shouting, but that battery well is really scary. I will wager some salt got in and has damaged one or both of those batteries. Also sorry, you won't like my next recommendation, but get them out and off your boat, clean the terminals and cable lugs bright and shiny with a wire brush, and put the batteries on a good automatic charger in a well ventilated area. When fully charged, put the batteries back in those nice battery cases and put the covers back on. The cover vents on those cases may still allow saltwater, I would duct tape them, and drill a hole just smaller than a 1/4 tube on the top of each cover, and stuff in a length of hose long enough run the other end overboard, or at least up and away from the access, so you cannot get salt in those batteries.

Notice the dull grey color of the battery posts? That is lead oxide corrosion, and it is a poor conductor. This can actually keep a good alternator from fully charging a good battery, with a very slow decline in over all charge. Before spending money on new batteries/alternators, I would try this first.

[GregW1309]

You have to get the alternator up to X rpm for it to start charging, so if you just started it and never went above idle the charge light may stay on.

[JD-MDR]

Originally Posted by Sailmonkey

Have you revved the engine? If it’s been a while since the engine was run the alternator may need a bit of persuasion to start charging.

I agree. I always have to rev my engine to get the alternator to kick in

[Mike Banks]

Your red light indicates no alternator output.

That could be due to several things--and lets start with the least expensive, even if it is possibly the least likely.

When you turn the starter switch--the exciter circuit is not being made--this will leave the alternator ineffective since it uses elecro magnets, which are energised by the battery voltage even when low. Once the alternator begins to charge, it is self-sustaining--but do not disconnect the battery before first connecting another in parallel with it while the engine is running.

Second thing to check is the plugs to the alternator harness--make sure all are clean and no broken wires--make sure field voltage sensor wire to battery (used by regulator) is not disconnected. Without it the battery will still charge but probably never reach its full charge capacity.

Still not charging? Now you need to remove the alternator and send it for testing. If it is old it may simply need new slip ring brushes--you can check these yourself--but they last a long time. While I have an alternator of some vintage out--it pays to do a full rebuild--new bearings, brushes, clean up and sometimes the coils need to be re-varnished. All of this you can do yourself it you have workshop space aboard or ashore.

Blown diodes in regulator means a new voltage regulator needs to be fitted. Some people elect to fit instead a remote smart regulator.

[Thumbs Up]

For the amount that you use your boat you could get by a small solar "battery maintainer"

[guyrj33]

Originally Posted by Mike Banks

Your red light indicates no alternator output.
...
Blown diodes in regulator means a new voltage regulator needs to be fitted. Some people elect to fit instead a remote smart regulator.

The alternator diodes convert AC to DC inside the alternator, they are not part of the regulator. The regulator varies the field current, controlling the power output of the alternator.

As others have said; clean up your batteries and mount them properly! They are one wake away from disaster.