Sterling Pro Charge Ultra

[WotEver]

A M12 or 1/2" set screw welded to the hull should do the job adequately but some may suggest M10. The good deep weld fillet should go right round the hex head. The use of a set screw ensures nuts can bear hard on the cable crimp terminals.

Yup. M12 would be best but if he only has modest electrics then M10 is fine as you suggest.

 

When I said 'stud' or 'bolt' I did of course mean set screw. Thanks for correcting me.

[Tony Brooks]

Interesting read this one. I have not seen this stud on mine, my elastictrickery all goes to the flywheel housing on t'engine - which is isolated by wooden mounts from the hull. Luckily I havent, no wait damn it I think I have! Well there's a slim change I haven;t cut the last bit of neg cabling to length and crimped the ends.

 

Don't the engine mounting bolts go right through the wood and the engine bed so as long as they are tight they should be making contact with the underside of the steel beds. However I think a visible bond might be a good idea.

 

 

 

[sirweste]

 

Don't the engine mounting bolts go right through the wood and the engine bed so as long as they are tight they should be making contact with the underside of the steel beds. However I think a visible bond might be a good idea.

 

 

 

 

No I think its separate bolts. So engine bolted to wood. Wood bolted to hull. I could be wrong. My hull is a good'en so there may well be a stud hiding somewhere down there. I'll get the meter on things tonight and see how the engine compares to the hull voltage wise

[Gareth E]

Another question about the Sterling charger: The amp readout on the charger: would this show a fairly steady output of 20 amps or will this reduce as the batteries become charged? The reason I ask is that I'm planning to charge at a fixed voltage rather than allowing a float voltage, I'll be using a generator. Otherwise I'll need to monitor the soc in a different way.

[WotEver]

As Max stated above. You will see the charge current slowly reduce. It's a curve, so the rate of reduction will slow down the longer the charge goes on. Because you're using a genny I'd suggest 3% to 2% should be your cut-off point to stop charging. Of course this monitoring only works if you have no other services running at the time.

 

However, if your batteries are old and tired you might never get down that low so a better decision might be to stop charging when the rate hasn't decreased over a period of 30 minutes. Eg if it's at 4% of your battery capacity at 3pm and is still the same at 3.30pm you can turn off the genny.

[Gareth E]

Cheers for the replies. My batteries are reasonably new. I plan to charge them daily subject to what I get from solar. So probably daily from November to February. I plan to charge them for perhaps an hour or so daily (I only use around 30 AH/day) then a longer charge once a week or so, taking them close to full. I have another question but I'll start another thread for this.

[WotEver]

I plan to charge them for perhaps an hour or so daily...

Try to make that two hours if you can

[Gareth E]

Back on this this morning.... I've had my voltmeter out trying to work out why the voltage when I touch the negative probe to the hull is lower than the reading I get when I touch the probe to the negative wire.

 

I think I know the problem: The voltage when I touch the hull matches that of the starter battery. Further checking; there is no connection from the negative of the leisure battery to the earth stud on the engine. This seems to indicate that the earth stud is doing its job but perhaps, the boat is badly wired!

 

Would I be right in assuming that it's bad news that there's no earth connection from the leisure? And if so, the solution is to link the negatives of the starter and leisure batteries with suitable wire, problem solved?

[WotEver]

Yes.

 

Have a read of this to give yourself a bit of background info: http://www.smartgauge.co.uk/earthing.html

Do you have two alternators? If not, how on earth are both batteries being changed?

[Gareth E]

I've had a quick read of that thanks. More reading required!

 

I only have 1 alternator. It's definitely charging the leisure battery because I see an increase in volts when I run the engine. I haven't checked the starter battery when the engine is running but definitely will now. The odd time I've checked it it read 12.8, rested.

 

It's an easy job to link the 2 negatives. I already have the cable with ring connectors from when I used to use 2 leisure batteries. A job for this afternoon. As a matter of interest, if I didn't do this, what would be the risks or potential downsides?

[Gareth E]

Been out with the voltmeter again. I found, this is the starter battery, that if I connect the negative probe to a bit of clean metal I get the same reading as if I touch it directly to the negative wire. So it seems the earth on the engine is doing its job. What threw me is that I also had a reading touching the negative to the hull, with the positive on the leisure battery terminal. A bright torch and a bit of feeling around revealed that the 2 negatives are in fact connected. That's great but the wire is thin, maybe 6mm. I've a feeling that this is very bad form?

[WotEver]

There are no short answers.

 

IF the alternator is connected to the leisure batteries and...

IF the two battery positives are connected by a relay when the engine is running...

 

... then the 6mm² link is probably okay.

But not great.

 

edited for clairty

Edited August 25, 2016 by WotEver

[WotEver]

A little test...

 

Engine running...

 

Meter +ve to Alternator D+

 

Meter -ve to Leisure -ve battery post - what's the reading?

Meter -ve to Starter -ve battery post - what's the reading?

Meter -ve to Engine - what's the reading?

Meter -ve to Hull - what's the reading?

Meter -ve to Leisure +ve battery post - what's the reading?

 

Clue... they should all be the same except for the last one which should be a very low reading.

[Gareth E]

Those test are on my to do list!

 

Does anyone know if Sterling chargers take their standby power from AC or DC? Reason I ask, I'm pretty well in the position to get going with the charger now but as I have no shoreline I would have to run the genny to set up the charger, that's if it uses AC standby power.

 

Thanks.

[WotEver]

Standby power? If the charger is plugged in, it'll charge. If it isn't it won't.

[by'eck]

Those test are on my to do list!

 

Does anyone know if Sterling chargers take their standby power from AC or DC? Reason I ask, I'm pretty well in the position to get going with the charger now but as I have no shoreline I would have to run the genny to set up the charger, that's if it uses AC standby power.

 

Thanks.

 

Not sure what you mean by standby power. Like most battery chargers the Sterling unit requires an AC input, this can be from shore power or generator as long as the latter is powerful enough to handle the start-up current.

 

The manual mentions a standby charge mode, but this just provides a lower float voltage to the batteries when they are left unattended fully charged for long periods.

[Gareth E]

Thanks for the replies. What I mean is can I set up the charger, select the custom program, choose the voltage etc. when DC only is connected or will the charger be 'dead' until I connect AC?

[WotEver]

It will be dead without mains voltage.

[by'eck]

Thanks for the replies. What I mean is can I set up the charger, select the custom program, choose the voltage etc. when DC only is connected or will the charger be 'dead' until I connect AC?

 

I think it's safe to assume it will be dead until the AC input that drives it is available.

 

Of course devices that use mechanical (DIP switch) rather than software controlled switching could be set up in advance of power-up, but don't think this applies to your charger.

[Gareth E]

Thanks for that.

 

One final question, I think! the manual says it's important to run the DC wires to the charger first then run to the batteries, rather than the other way round. I don't really understand this, as the charger won't be switched on until the AC is switched on or in my case, the generator running and plugged in to shoreline.

 

Anyway: The wiring to the batteries is already in place. I was thinking that if I turn off the battery isolator before wiring the DC to the charger this will give the effect that the battery wires aren't connected. Then switch the battery isolator on after I've completed the DC wiring to the charger. Hopefully this will be OK but it would be good for someone with more experience in these matters to confirm this. And maybe, explain why it matters at all, if the charger is effectively switched off?

[WotEver]

The reason they state it the way they do is so that you don't have two 'live' tails flailing around as you connect the charger. If you connect to the charger first then the wires are dead until you connect them to the battery.

 

Tony