Re: nb Virgo

Comments interspersed.....

Guy Morgan wrote:
> Hi all
>
> I'm a bit (only a bit) clearer about Virgo's various systems now I'm back at base after a week on the boat.
>
> Among the other things I now know is that the fridge is a 12 volt one and keeps going OK overnight when we moor without flattening the batteries. I also know that the alternator puts out 14.5 volts without the help of an external regulator

Right that's good. Some idiots will *still* try to tell you that you need to fit one. I can *assure* you (as can several others here), it will achieve either nothing or next to nothing depending what model of controller.

> and that there's a Durite 180A split charge relay installed.

Ok. They tend to burn out, due to the "180A" being nothing short of a blatant lie. I don't think I need to convince you of this but for the benefit of other readers....

http://www.smartgauge.co.uk/more_relay.html

>
> Following the previous responses to my questions I am a little confused by the suggestion that one needs a ginormous battery charger. Surely this is only the case if there's a heavy drain on the batteries when the engine isn't running and when there's no shoreline mains supply. I can't imagine a situation where the domestic batteries are very discharged and there's mains to drive the charger. If there's mains then per se the loads are going to be running off mains (breadmaker, microwave, laptop power supplies, power tools, TV etc) so not discharging the batteries and if there's no shoreline supply then the charger isn't going to be working anyway. Returning from a trip the batteries are going to be well charged from the alternator. Hence my conclusion that, in effect, the mains charger only needs to do a bit more than keep the fridge consumption balanced.
>
> The only explanation I can see is if lots of things ran off 12 volts rather than mains. I can't see that happening on Virgo.
>
> I'm obviously missing something but anxious not to spend a vast amount of money on a damned great charger if a 20A one will do.
>

Read this....

http://www.smartgauge.co.uk/technical1.html#charger

Which explains the advantages and disadvantages of large and small chargers.

You have to consider what it's there for. As you can imagine, as a result of my job, I can have *any* charger I want. I have 2 fitted, for backup purposes. One is a 40 amp, the other is a 20 amp. We only use one at a time. If we go cruising, the batteries are full when we get back to shorepower. If we sit on the boat on shorepower, either will keep up with demands. As you say, all the heavy stuff will be running from 230 volts anayway.

The only real reasons for a large charger are if there is no (or an inadequate) charging system on the boat or very large DC loads. The batteries then need quick, full charging from shorepower and a way to keep up with the large DC loads.

Now re-reading that, it seems all I've done is repeat what you said. So you're right! You don't need a great big charger.

> WRT mains - as i suspected there's simply a 16A plug on the back end bulkhead and a "garage" unit in a cupboard feeding a couple of sockets independent of the inverter. No GI or the like. Questions. 1) I know all cable should be stranded but for mains does that mean round cable such as used for extension leads and the like?

Yes.

> 2) What was the objection to cheap "site" isolation transformers such as sold by machine mart? I know they don't have a large continuous rating but am I really likely to pull 3kw for hours on end? I reckon not. The heaviest load is likely to be the immersion heater once installed which would be 1 or 1.25 kW AFAICS
>

They're 110 volt. That may be the first problem.

If you can get a 230 volt one, and make sure you run it well below it's rating there won't be a problem. But you might have to pull it apart to sort the earthing arrangements out.

> So trying to keeep things basic I reckon I need a Gibbmo so I know what's going on battery-wise, a Gibbmo add-on to manage the charging regime, a battery charger of reasonable proportions (say 20A max) to just do a bit more than keep up with the fridge and a bigger inverter than the 400W one fitted ATM. I think maybe a 1300w one so I can run the vacuum cleaner if needed as long as the engine is running. I can't see any reason to have a true sine wave one ATM as long as all the various wall-wart PSUs etc will run on mod sine wave.

Old style ones did, some of the new switch mode ones have problems.

> The only fly in the ointment might be the breadmaker.

They generally do *not* run on modifed sinewave.

The price of pure sinewave has now fallen to an acceptable level. I can't really see any reason not to fit one anymore. Except "I want it for next to nothing". They are now the same price that a modified sinewave inverter was 5 years ago.

The other point is that the modified sinewave inverters have had to be *severely* built down to a price in order to keep some market share. They are now absolutely shyte. Horribly unreliable. Due to the differences in the way they work the pure sinewave units stress the components to a *much* lesser degree.

Modified sinewave inverters have now, in my mind, become an obsolete consumable. When it breaks, bin it. And the ones that are being sold new now, break, a great deal.

I think a pure sinewave would be a better investment. The two on Lionheart have had the living hell kicked out of them for 3 years and never let me down. I even ran a small arc welder from one. I've known 1500 watt modified sinewave inverters blow up when asked to power a 350 watt electric drill. Not as a fluke, but I've done it to 4 or 5 brand new ones when testing them.

I'll let others answer the other Qs

--
Gibbo

Emails to this email address are deleted at the server. I don't even get to see them. If you need to email me you can do so via my website.
.

Relevant Pages

  • nb Virgo
    ... Among the other things I now know is that the fridge is a 12 volt one and keeps going OK overnight when we moor without flattening the batteries. ... Following the previous responses to my questions I am a little confused by the suggestion that one needs a ginormous battery charger. ... Surely this is only the case if there's a heavy drain on the batteries when the engine isn't running and when there's no shoreline mains supply. ...
    (uk.rec.waterways)
  • Re: nb Virgo
    ... Surely this is only the case if there's a heavy drain on the batteries when the engine isn't running and when there's no shoreline mains supply. ... I can't imagine a situation where the domestic batteries are very discharged and there's mains to drive the charger. ... I'll need to look into costs of smallish charger andpure sin inverter against a combi unit. ...
    (uk.rec.waterways)
  • Re: nb Virgo
    ... the suggestion that one needs a ginormous battery charger. ... only the case if there's a heavy drain on the batteries when the engine ... isn't running and when there's no shoreline mains supply. ... fridge on and the landline fails and is off for most of that time, ...
    (uk.rec.waterways)
  • Re: nb Virgo
    ... the suggestion that one needs a ginormous battery charger. ... only the case if there's a heavy drain on the batteries when the engine ... isn't running and when there's no shoreline mains supply. ...
    (uk.rec.waterways)
  • Re: More Battery Recharging Questions
    ... I have a new Yamaha EF1000isc generator, ... I suspect that the charger may be a lot faster. ... I believe that charger is "only" a 10 amp charger. ... If you have golf cart batteries and run them half ...
    (rec.outdoors.rv-travel)