Power nightmare

[nathanlee]

I was on a buoy in West mersea over night. This morning it started getting very windy, so I decided I wasn't sailing.

Checked the battery... 12.75v. Damn, it's flat. I hoped the solar cells would put some power in during today, but they've shorted out somehow. They are trickling through 1.5v, which isn't going to charge anything. I've put the multi meter right on the source too, and still get the same voltage. So I'm stuck with a dead battery and no way to charge it. This puts a big problem on my travels since I have no charts without power, and no tiller pilot.

To top it all off, my laptop had ran out of juice too, and so I couldn't charge my phone, which after finding out yesterday that my old man has had a suspected heart attack, was quite important. I've ended up parking hte boat on the west mersea hammer head (which I'm not allowed to do) but I had no choice because I couldn't get ashore any other way in this wind. Mooring up single handed in 25 knots is bad enough.
Thakfully, West Mersea Yacht Club are a very nice bunch of people and have let me charge my laptop (and thus phone) and have a shower. I would have been in utter despair without that I think.

So currently, it's a bloody nightmare and I don't know what to do.

 

[sailorman]

12.75v = good voltage / capacity /forums/images/graemlins/confused.gif

 

[Phoenix of Hamble]

Nathan,

Stick your post on the East Coast Forum... plenty of people around that way, and i'm sure someone would help you get your battery charged back up...

We're 100 miles away, otherwise, we'd gladly offer you a charge up....

 

[Chris_Robb]

[ QUOTE ]
Checked the battery... 12.75v. Damn, it's flat.

[/ QUOTE ]

12.75V is well charged. I would check all your connections on the batteries, as that will be your problem, if it won't start.

As for the panels - not sure what you should get, but I thought if the sun was shinning you would get at least 15V, and if you have a regulator that woudl have raised your battery voltage to at least 13.8V

 

[nathanlee]

I thought 12.75 was low for a sealed battery? The inverter decided there wasn't enough power to run anyway, and it usually does.

The solar cells are my main concern. I can afford a new battery if needs be, but not cells.

And the panels usually do kick out 13+volts, and it is sunny here, even if very windy, so I can only presume I've fried something if all I'm getting i 1.5 /forums/images/graemlins/frown.gif

 

[alan17]

I confirm 12.75v is NOT low.

Use a digital volt meter and check voltage at each connection as a load (starter) is applied. The fault will be a poor connection or a duff starter.

 

[nathanlee]

[ QUOTE ]
I confirm 12.75v is NOT low.

Use a digital volt meter and check voltage at each connection as a load (starter) is applied. The fault will be a poor connection or a duff starter.

[/ QUOTE ]

The starter is not the problem, I don't have one. It's keeping the domestic topped up to run the tiller pilot and chart plotter, as well as the inverter to keep the laptop running now and then (although that's not quite as essential).

Less than a hundred sea miles into 'round britain and I'm stopped dead. This is seriously annoying. :|

 

[sailorman]

to charge a battery the charging source ie panel/ alternator has to have an out-put voltage greater than the batteries therefore the panels will give say 14v on a good day.
have you got a bad connection

 

[nathanlee]

[ QUOTE ]
to charge a battery the charging source ie panel/ alternator has to have an out-put voltage greater than the batteries therefore the panels will give say 14v on a good day.
have you got a bad connection

[/ QUOTE ]

No. I've tried at the charge controller and at the on deck plug, directly wired to the panels. There is definitely only 1.5v coming from it.

 

[snowleopard]

Sealed ('maintenance free') batteries behave just like ordinary car batteries, i.e. 12.8v = full, 12.2v = half empty/lowest regular discharge.

I'm not clear what you are measuring when you get 1.5v from the solar panels - if they are on open circuit you should probably see 20v or more. Once connected to the battery they should show at least the voltage of the battery or 13.5-14.5v while they are putting charge in. I imagine you have a diode in the circuit to stop back-flow at night. If tthey really are showing 1.5v in sunlight they are seriously knackered.

 

[Wunja]

My solar panel has a little connection box on the back which includes a diode to prevent discharging the battery. This is just connected via the same screw terminal as the wire connection. Assuming your's is a similar construction, I would check that there is no corrosion in this area and that the diode is connected properly. You could also measure the voltage upstream of the diode.
My solar pannel gives 17.5V on even a dull day, just no usable current unless it has direct sunlight.

 

[LadyInBed]

Disconnect Solar panel
I assume that you haven't got a regulator in circuit.
If it has a diode in circuit check voltage both sides of diode.
With sun shining you should be getting a voltage approaching 20v both sides of the diode.
If it is around the 20v mark one side and 1.5v the other then the diode has blown.
1.5v both sides of diode or no diode, then the Solar panel is u/s.
Options:
- Cheap mains battery charger and mains extension lead to shore power.
- Take battery ashore to garage/ marina office/ friendly house wife and ask if they will charge it.
- Bypass/ replace Diode if that is the problem.
- If there is a regulator in circuit, take it out and start again.
Note: Cheap mains battery charger and mains extension lead to shore power is worth having anyway.

 

[absit_omen]

Well, thats a lesson in quite a lot really.

Anyway, forecast is NE and E 4-5 (which means 6) for the next five days or so. You have plenty of time to sit and reflect.

 

[PilotWolf]

Just a thought... you say meter is reading 1.5V and it's been suggested that you should be getting 15V from them (solar cells) was the meter was set to the wrong scale?

W.

 

[nathanlee]

[ QUOTE ]
Just a thought... you say meter is reading 1.5V and it's been suggested that you should be getting 15V from them (solar cells) was the meter was set to the wrong scale?

W.

[/ QUOTE ]

I wish! /forums/images/graemlins/tongue.gif

After a lot of prodding, filling, drilling, screwing and crimping, I've narrowed it down to the charge controller.

The deck fitting was knackered by sea water, so I've replaced it. Now, I'm getting 21v at the charge controller end of the wire. If, however, I plug it into the controller, it drops to c1.5v at both the input and output.

I have had a good lesson in setting off from a pontoon in 25knots of wind, as well as picking up a mooring buoy in the same though. /forums/images/graemlins/smile.gif

 

[Phoenix of Hamble]

Have you resolved the battery charge condition yet?

While it sounds like you are making progress, something still doesn't stack up quite right here yet......

 

[Billy_Mizzen]

PM sent

 

[misterg]

Ditch the charge controller, and connect the panel direct to the battery (via your fuse at the battery end, of course ... ). If you're worried about over charging, you can always disconnect it for a bit. IIRC, your relative panel / battery sizes are marginal for warranting a controller, anyway.

Andy

P.S. It's not a controller from a wind generator, is it?

 

[Phoenix of Hamble]

Thats what I'd do.... with your consumption, and with it being a relatively small panel anyway, I think you'd struggle to overcharge..... maybe caution though for when you fit a second panel?

Edit: make sure you do have a diode though, otherwise you risk discharging through the panel overnight....

 

[moondancer]

One other thing that might help. If you can get a 12V lead that works for your laptop that should be far more economical on power than a 12v to 240v inverter that then has to be converted by your laptop lead power supply to low voltage again. Also most inverters convert to a very crude simulation of AC current that isnt that healthy to things like laptops. If you could get someone on your route to drop one into you I am sure that this forum would rise to the challenge.