Going Round In Circles, Learning Curve Too Great. . .

[Wassat]

I have lurked on these forums for quite a while and have learnt much from all who post, But electricity completely evades my comprehensive powers.

 

I have the following electrical setup what is the best way to manage it, is there any particular monitor that is simple to understand. One that shouts at me to do things and when, so that I dont foul up my batteries.

 

600 (six hundred) watts of solar panels,

Outback Flexmax 80 MPPT controller

Sterling Power Combi Inverter 2.5 Kw Pure sine wave.

Sterling Alternator to Battery Charger.

6 (six) Trojan T105 6 volt 225 amp hour batteries coupled in series and paralell to give 1350 amp hours.

2.5 Kw Travel Power Generator.

Plus a starter battery that is recharged off the engine.

Last but no means least a mind that goes into overdrive thought breakdown when presented with anything electrical.

 

All help will be gratefully received.

[RLWP]

HMS Victory had no electrics at all!

 

Richard

[nicknorman]

I have lurked on these forums for quite a while and have learnt much from all who post, But electricity completely evades my comprehensive powers.

 

I have the following electrical setup what is the best way to manage it, is there any particular monitor that is simple to understand. One that shouts at me to do things and when, so that I dont foul up my batteries.

 

600 (six hundred) watts of solar panels,

Outback Flexmax 80 MPPT controller

Sterling Power Combi Inverter 2.5 Kw Pure sine wave.

Sterling Alternator to Battery Charger.

6 (six) Trojan T105 6 volt 225 amp hour batteries coupled in series and paralell to give 1350 amp hours.

2.5 Kw Travel Power Generator.

Plus a starter battery that is recharged off the engine.

Last but no means least a mind that goes into overdrive thought breakdown when presented with anything electrical.

 

All help will be gratefully received.

 

If its all working satisfactorily, perhaps there is no problem? You don't say how you use the system - liveaboard, holiday boat? spend a lot of time tied up, or always cruising? On shore power? Use heavy electrical consumers a lot? etc etc.

 

With all that solar, you should be OK in summer I would have thought, unless you use a lot of heavy electrical consumers such as electric kettles, heaters, toasters etc.

 

Anyway, to know the state of charge of your batteries you could consider a Smartgauge. This allows you to avoid excessive discharge and to know when the batteries are fully charged etc. It simply reports the current state of charge as a percentage, and is easy to install, requiring only 2 wires, one to each of +ve and -ve terminals of the domestic battery bank.

 

However the Smartgauge doesn't tell you the instantaneous current going into /out of the batteries, and if you want to know that you need to add an ammeter fed from a shunt. This is harder to install and considering your admission of technophobia, it might not be that much use to you. Therefore I think my first suggestion of a Smartgauge is what you need. You simply want to avoid the % state of charge going below around 50% and regularly fully recharge your batteries, at least once a week, til the gauge says 100%, either by solar or by using the engine charging system.

 

As a general point, when contemplating using a heavy AC consumer for a prolonged period, such as a washing machine or tumble drier, I would recommend doing so with the engine running so that the travelpower supplies the juice. Although the inverter is also capable of supplying the juice, it will take a lot out of the batteries.

 

That's about all I can come up with unless you have more specific questions.

[grahame r]

I stand to be corrected here, but if you connect 2 x 225Ah 6v batteries in series don't you get 1 x 225Ah 12v battery? and connecting 3 of these in parallel would give you 675Ah. I only mention it because if you buy a monitor that counts amps it will require the total capacity to be defined.

[nicknorman]

I stand to be corrected here, but if you connect 2 x 225Ah 6v batteries in series don't you get 1 x 225Ah 12v battery? and connecting 3 of these in parallel would give you 675Ah. I only mention it because if you buy a monitor that counts amps it will require the total capacity to be defined.

Well spotted, I missed that!

[Wassat]

My apologies my maths up the creek as usual.

[Grace and Favour]

My apologies my maths up the creek as usual.

What you really need to do is a power audit - calculate the energy used per day by all - every single electrical item - on your boat.

 

Then you'll know how much power you need to provide

 

 

Then folks will be able to tell if you've got sufficient provision

 

(PS - I didn't think Travel Power had a 2.5Kw model - I thought they did either 3.5Kw, 5.0Kw or 8Kw models only

Edited July 15, 2013 by Grace & Favour

[BargeeSpud]

What a shame we lost Gibbo. Now he WAS the man.

[Hawkmoth]

Just slightly off topic.

Does anyone out there know if you can buy an ammeter that works without a shunt, as a DC clamp meter does?

Surely there must be a panel mounted, non contact ammeter out there, at reasonable cost of course?

[Chris Pink]

Just slightly off topic.

Does anyone out there know if you can buy an ammeter that works without a shunt, as a DC clamp meter does?

Surely there must be a panel mounted, non contact ammeter out there, at reasonable cost of course?

 

Why? It's not that difficult to install a shunt and then it's accurate.

 

Outback Flexmax 80 MPPT controller

 

 

Your Outback will be giving quite a lot of information. I think you need education rather than a gadget (except perhaps Robbie from Lost in Space). Do you have no metering at all with this lot which is quite a sophisticated set up?

 

Where are you based?

What you really need to do is a power audit - calculate the energy used per day by all - every single electrical item - on your boat.

 

 

 

Whereas a power audit would be a useful exercise my dear petite chatte, it's not going to be that useful in this case. It's going to be relatively easy to find out how much is being used (and how much is going in)

 

 

 

 

Question to the OP;

 

Is your solar keeping up?

How many amp hours per day do you get? (the Outback will tell you)

 

If the answer to the first is yes, then the second is your usage (the Outback will stop once the batteries are full)

[sassan]

What you really need to do is a power audit - calculate the energy used per day by all - every single electrical item - on your boat.

Never calculate what you can measure!

 

Regarding gadgets:

We've got a voltmeter rigged up at each end of the boat. Not perfect (have to account for voltage drop from the wiring to the front), but it is enough to tell us when we're getting low.

 

After a while you get a feel for what it's going to be, anyway.

[Hawkmoth]

 

Why? It's not that difficult to install a shunt and then it's accurate.

 

 

 

 

 

Chris, I do know that. I have two already on my system.

What I was asking is does anyone know if such a thing can be had, at reasonable cost?

[bottle]

Wassat

 

No doubt this thread will go all technical but the simple answer is fit a Smartgauge.

 

Never let the reading go below 50% without recharging.

 

That's the simple answer now to learn more read all the posts and get even more confused.

 

ps. If you click the link go to the 'technical' page, all you need to know and more.

[Chris Pink]

Chris, I do know that. I have two already on my system.

What I was asking is does anyone know if such a thing can be had, at reasonable cost?

 

No. As far as I know.

 

There wouldn't they are inaccurate and only give and indication of current activity, ie charging or not and this information can be found in other ways. If you're going to install something the a shunt ammeter is the way to go, why would anyone manuifacture anything else? The only reason for a clamp ammeter is to obviate breaking connections, if you are going to install something this is irrelevant.

[Hawkmoth]

Wassat

 

No doubt this thread will go all technical but the simple answer is fit a Smartgauge.

 

Never let the reading go below 50% without recharging.

 

That's the simple answer now to learn more read all the posts and get even more confused.

 

ps. If you click the link go to the 'technical' page, all you need to know and more.

Yes, I know all the reasons that people give for fitting Smartguage, and all the other counters and the like. All I wanted to know was "Is there a contactless panel mounting ammeter that works similar to the clamp multimeters you can buy.

CP seems to think they are inaccurate, but testing mine against the shunt driven ammeter I use at present shows it to be pretty good, ie 1-2 amps @ 70 amps.

Bob

 

No. As far as I know.

 

There wouldn't they are inaccurate and only give and indication of current activity, ie charging or not and this information can be found in other ways. If you're going to install something the a shunt ammeter is the way to go, why would anyone manuifacture anything else? The only reason for a clamp ammeter is to obviate breaking connections, if you are going to install something this is irrelevant.

I don't find the clamp meter that I have to be inaccurate. As I said to Bottle, it seems to be accurate to 1 or 2 amps @ 70 amps against my shunt driven ammeter.

Bob

[Chris Pink]

Is that one of the clippy ones or one like a Fluke 322?

[Mat B]

Had one of these on my previous boat, worked fine. Depends what you want to measure.

 

m@

[Chris Pink]

The issue with those is not accuracy it's that you have to pass the whole current through them which involves taking the alternator (etc) up to the panel and down again, and they usually have 5mm ring terminals.

 

FIne in the days of 35A alternators (ish) but absolutely useless in a system like the OPs (always assuming you can find a 300A version)

 

Obsolete.

[nicknorman]

Just slightly off topic.

Does anyone out there know if you can buy an ammeter that works without a shunt, as a DC clamp meter does?

Surely there must be a panel mounted, non contact ammeter out there, at reasonable cost of course?

 

I'm not aware of a complete panel mounted meter with clamp sensor, however LEM make a wide range of closed loop hall effect sensors that output a voltage proportional to the current, with an accuracy of better than 1%. Closed loop means that the usual inaccuracies of a hall effect sensor ie non-linearity, thermal drift etc are eliminated by having a secondary winding with perhaps 1000 turns. The system passes a current through the multi-turn winding so as to produce an opposite sense magnetic field to cancel out the field from the main current carrying wire, until the net field is zero. Then the strength of the required current is (say) 1000th of the actual current, and the device outputs a voltage accordingly, or some use the 4-20ma current loop type of output. Because the sensor is only required to detect zero magnetic field, the usual errors are eliminated.

 

So whilst not a complete package, using one that outputs a voltage, with a suitable calibrated voltmeter to read current, would give the effect you desire. The only thing I notice is that whilst they can measure say 500A, they don't seem to come in sizes that allow the usual 70mm^2 cable to pass through, and not that cheap! An example: http://uk.rs-online.com/web/p/current-transducers/2072990/

 

The only reason for a clamp ammeter is to obviate breaking connections, if you are going to install something this is irrelevant.

Plus you can measure current in a conductor at significantly different voltage to your normal supply (not relevant for a boat, I admit) and you are measuring without the intrinsic voltage drop of a shunt (which I also admit is trivial for a boat), and sending a much larger voltage on the long cables to the meter, reducing the chances of interference (ditto!). So there are some advantages, though I agree they are probably not appropriate for a boat.

Edited July 16, 2013 by nicknorman

[bottle]

Yes, I know all the reasons that people give for fitting Smartguage, and all the other counters and the like. All I wanted to know was "Is there a contactless panel mounting ammeter that works similar to the clamp multimeters you can buy.

CP seems to think they are inaccurate, but testing mine against the shunt driven ammeter I use at present shows it to be pretty good, ie 1-2 amps @ 70 amps.

Bob

I don't find the clamp meter that I have to be inaccurate. As I said to Bottle, it seems to be accurate to 1 or 2 amps @ 70 amps against my shunt driven ammeter.

Bob

 

My reply was addressed to the OP Wassat.

 

That is why it had Wassat at the beginning..

[Hawkmoth]

 

My reply was addressed to the OP Wassat.

 

That is why it had Wassat at the beginning..

Bottle,

Sorry, got my nickers on a twist

Bob

 

I'm not aware of a complete panel mounted meter with clamp sensor, however LEM make a wide range of closed loop hall effect sensors that output a voltage proportional to the current, with an accuracy of better than 1%. Closed loop means that the usual inaccuracies of a hall effect sensor ie non-linearity, thermal drift etc are eliminated by having a secondary winding with perhaps 1000 turns. The system passes a current through the multi-turn winding so as to produce an opposite sense magnetic field to cancel out the field from the main current carrying wire, until the net field is zero. Then the strength of the required current is (say) 1000th of the actual current, and the device outputs a voltage accordingly, or some use the 4-20ma current loop type of output. Because the sensor is only required to detect zero magnetic field, the usual errors are eliminated.

 

Thanks Nick, that confirms what I've found. I just thought I might be missing something or that someone out there knew of one,

Bob

[bottle]

Bob

 

Apology not necessary but thanks anyway.