Switchmode charger unhappy with generator

[concentrik]

This charger:

http://bit.ly/p4bogL

really doesn't like this generator:

http://bit.ly/nbsGLe

which is a bit of a shame because I bought them to be used together. The charger clicks and the LED charge stage indicators flicker wildly. There is no output voltage. The charger works OK on mains power.

The generator powers my laptop fine, via the normal PSU (which is also a switchmode type).

Is there some general wisdon which procludes the use of SMPS chargers with inverter gennys?

 

[Barry Jones]

There is a few problems with your links, but at first glance, it sounds like the output waveform from the generator is not clean enough for the charger microprocessor.

 

[steve28]

it should work fine, its pure sine output should work most electronics.
which charger do you have, most of them a a PFC circuit on the input that allows very ragged mains inputs from generators

 

[savageseadog]

You could try some extra filtering or possibly a voltage stabilising transformer.

I suspect the problem might be more in the voltage stability than waveform department

 

[Pagetslady]

When I first connected my generator to my shore line circuit on board I got a Polarity fault light. After making a few inquiries I was told to connect the Neutral to the earth in the geny output plug, this cured the polarity fault and my charger works fine.
Is it just possible this could be the cause.
Mike

 

[starfire]

Also, sometimes the voltage regulation on the generator can get upset with smps type psus.

Try connecting a small resistive load at the same time as the charger, say a 60w light bulb.

It may just do the trick.

 

[TrueBlue]

I have no real experience on this, but -
as the genny auto throttles depending on the demand, could it be that the charger does not behave as a resistive load ('cos it's electronic) thus fooling the genny to give not output/

Seems a bit daft, but I might be right.

Can you connect another load - lead lamp, small heater, whatever, that will give a fixed load.

Do report back if that solves the problem.......

 

[Beyondhelp]

Its not always that unusual to have two switch mode power supplies get upset with each other.
I'd guess that its a bit of both going on here. I suspect that the output of the generator whilst 'sine wave' is probably a rather crude sign wave.

However its more likely that its the charger that's at fault. The first step within the charger is to convert the mains AC to DC. It may be at this stage which the charger does not have decent smoothing and thus its interfering with its control circuitry.

 

[exfinnsailor]

240v 900w output is 3.75amps which is enough to drive your laptop power supply but is not enough to power a battery charger that puts out 20amps which will be using about 7amps. Which is why the battery charger works from the mains but fails to get going from a generator. What you need is a generator that puts out 12v which you appear to have. 5 amps at 12v. You could try a smaller battery charger from Maplins and if it does not work take it back. They will refund anything you buy if you return it promptly and say it does not do the job.

 

[Beyondhelp]

That charger will not be using anything like 7amps.

Charger output lets say 15v @ 20A max (it probably wont even do that) = 300watts.

Lets say its 80% efficient (it will be better than that) that's then 375 watts.

So 375/240=1.6 amps. Well within the generators capability.

You have however made me think of another thing, and that is the charger may have a huge inrush current. That could be upsetting the generator.

 

[cliff]

Is there some general wisdon which procludes the use of SMPS chargers with inverter gennys?

Hope not as I have one which runs happily of my inverter genny. Having said that I did have problems running fluorescent lights of it - problem solved by connecting a normal filament (incandescent) 100W bulb to the genny output - no idea why it worked but the fluorescents sprang into life and burned nicely.

240v 900w output is 3.75amps which is enough to drive your laptop power supply but is not enough to power a battery charger that puts out 20amps which will be using about 7amps. <snip>

20A@14.4V => ~ 288w - say 300w or 1.25A @240V figures from (see page 12) Switchmode chargers have input fused at 2A for 20A output so where do you get 7 Amp from?

Oops beaten to it

 

[exfinnsailor]

240v 900w output is 3.75amps which is enough to drive your laptop power supply but is not enough to power a battery charger that puts out 20amps which will be using about 7amps. Which is why the battery charger works from the mains but fails to get going from a generator. What you need is a generator that puts out 12v which you appear to have. 5 amps at 12v. You could try a smaller battery charger from Maplins and if it does not work take it back. They will refund anything you buy if you return it promptly and say it does not do the job.

Sorry about that. Just Gooooooooooogled battery charger and looked for one that gave input rating not a lot do.

 

[exfinnsailor]

What about one of the old fashioned variety without all the electronics

 

[JerryHawkins]

Genny setting

Does the genny have a switch for low/variable output and full power? I have Honda EU10i with a tortois/hare switch. When my batteries are a bit low and I connect the mains charger I can't use the genny in the 'tortois' position as it just 'hunts' and the charger doesn't work. I need full power (full speed) on the genny until the batteries get some charge into them after which I can switch the genny back to 'tortois' mode.

 

[halcyon]

240v 900w output is 3.75amps which is enough to drive your laptop power supply but is not enough to power a battery charger that puts out 20amps which will be using about 7amps..

It's not a amperage problem, but what type of load and / or how the generater produces 240 VAC.

It is possible the waveform generated by the genny is not suitable for the mains charger, as it uses the AC waveform as it's basis for the switchmode circuit.

Or the inductive load is causing the genny output voltage / waveform to collapse. Or it could be a bit of each.

Did a lot on this 25 years ago checking gennies to our battery chargers for Sealine, so full detail now hazey, basically small ones were dodgy. The answer is to put a scope on the mains and watch the genny output waveform I'm afraid.

You could try a simple transformer based charger, less effected by waveform, might help to decide if it's a genny or SM charger problem

Brian

 

[concentrik]

Some more information - from Clarke, the genny people, who insist that this model produces the most stable output of all their units in terms of voltage and frequency and waveform shape - as per their spec:

Ideal for providing a ready source of electrical power when, for example, out camping, caravanning, or enjoying a boat trip. The 'Pure Sine Wave Technology' controlled electrical output ensures the delivery of clean & stable power - vital when running sensitive electrical and electronic equipment - computers and laptops, for example.

I'm informed that "the unit produces 3-phase DC initially, which is then inverted to 240V ac and crystal locked for frequency."

Still waiting to hear from the charger people.

I expect I'll have to ditch one or the other but I'm updating the post to contribute to the greater sum of knowledge...... which I have often benefitted from on this forum.

 

[DaveS]

I'm informed that "the unit produces 3-phase DC initially, which is then inverted to 240V ac and crystal locked for frequency."

3-phase DC is an interesting concept...

I think what they really mean is: "the unit produces 3-phase AC initially, which is rectified to DC, then inverted to 240V AC and crystal locked for frequency".

To be a bit pedantic: do you think they know that the UK's standard voltage was re-defined as 230V quite a few years ago? (OK, I know that given the declared tolerances nothing actually happened on the ground, but still...)

 

[concentrik]

Or..

maybe he meant: [Wiki]

Midway between ordinary DC motors and stepper motors lies the realm of the brushless DC motor. Built in a fashion very similar to stepper motors, these often use a permanent magnet external rotor, three phases of driving coils, may use Hall effect sensors to sense the position of the rotor, and associated drive electronics.

But I think I can visualise phased DC - wouldn't that be a voltage of varying amplitude which doesn't cross 0V? Like unsmoothed full-wave rectified AC, with it all 'above the line'...... at a loose end as you can probably tell! The 240v bit was my error, although round our way in December I'd swear we're sharing with the Large Hadron Collider....

 

[Barry Jones]

IMHO The fact that the generator is advertised as having a sine wave output doesn't always mean its a pure sine wave in practice.

I like to measure it rather than going off half-cock on a wild goose chase.

Your gennie is one of those at the cheaper end of the spectrum and I suspect that the charger might be a bit fussy about its waveform.

Assuming that the output waveform is very pure and clean, then it can only be that it can't cope with the start up current.

Are you connecting the genset directly to the charger ??

Do you know anybody with a Honda EU10i near your mooring that you can ask them to try ?

maybe he meant: [Wiki]

Midway between ordinary DC motors and stepper motors lies the realm of the brushless DC motor. Built in a fashion very similar to stepper motors, these often use a permanent magnet external rotor, three phases of driving coils, may use Hall effect sensors to sense the position of the rotor, and associated drive electronics.

But I think I can visualise phased DC - wouldn't that be a voltage of varying amplitude which doesn't cross 0V? Like unsmoothed half-wave rectified AC, with it all 'above the line'...... at a loose end as you can probably tell! The 240v bit was my error, although round our way in December I'd swear we're sharing with the Large Hadron Collider....

 

[concentrik]

Are you connecting the genset directly to the charger ??

Do you know anybody with a Honda EU10i near your mooring that you can ask them to try ?

Yes, and no unfortunately. I take your point entirely, so I think I'll bring the genny back ashore and look at the o/p voltage on my 'scope (mains, drat!) under varying loads. If it isn't as pure as the driven, it can go back, Mr Clarke.