Another generator/charging thread and yes I have searched.

[PhilipA]

I have just won a Yamaha EF1000 generator on ebay. This is an older EF1000 which is not pure sine wave. Its output is 700W continuous at 240V 50Hz. or 10amps at 12 volts which is high for one of these.

My plan is to use it for an hour or two a day in hot weather to recharge my second AGM 95AH battery which has a max continuous input of 20amps. This runs my 40 litre engel and lights and the battery gets a drubbing in the tropics when the night temp is 20+

My thought at the moment is to buy a 15-20 amp 2 stage charger although Jaycar have a 15amp 5 stage charger for $149 which looks to fill the bill. A couple of hours should give another day.

Anyone had experience driving a microprocessor controlled charger with a non sine wave generator. I would think a Yamaha would be superior to a GMC et al in voltage control. Even a 2 stage transformer type charger would have to have some sort of electronic control.

I believe from the limited info I could find on google that the EF1000 is well regarded.
Regards Philip A

[Blknight.aus]

IT depends on how well buffered the switchmode side of the charger is.

some dont mind noisey power others do.

occasionally plugging an incandescent light onto the same feed as the charger will knock the edges off the waveform enough to keep the switchmode power supplies happy.

[slug_burner]

I can't see it as a problem. The first thing that will be seen by the generator is a rectifier and filter/capacitor (maybe a fuse first) of some sort, this will then feed a chopper if it is a switch mode supply. If it is a big heavy power supply as in the older tranformer based power supplies, the first thing that the generator will see will be a transformer, this will be a fairly good filter and knock the edges of the wave form leaving you with a good sine wave, then this would feed a rectifier/filter and regulator.

Should work.

[Taz]

This is probably a stupid question; but would'nt the DC feed be the most efficient way to charge such a battery?

[mark2]

This is probably a stupid question; but would'nt the DC feed be the most efficient way to charge such a battery?

Probably the most efficient but not the necessarily the fastest -10A for the DC output versus more than that for a big charger.

[Blknight.aus]

no, the DC feed, for want of a better description comes from the excite side of the alternator that is driven by the engine. ITs only a handfull (8-10) of amps. using this while your drawing other power can cause both he 12v and the 240v voltages to dip.

If you sling a battery charger off of the 240v you can push more amps if you need to. I used to use a cheap 700w genset to drive my 30A oldschool battery charger and it used to do so quiet well, reasonably quietly and while running a couple of small 240v lights.


From what I remember from a conversation with a Tech the reason some switchmode power supplies don't like running off of square or modified wave power is because the change over in the voltages is too harsh and sudden, sort of like slamming your shift from 1st to reverse without backing off of the throttle or easing up on the clutch, sure you can do it for a while but eventually somethings gunna give.

[slug_burner]

Depends on how that dc feed is generated. As mark2 said, ten amps from the DC feed is a lot less than the 700W available, 12V x 10A is only 120W. A half decent power supply should be able to give you about 30 A at 12 V from the 700W produced by the generator.

[slug_burner]

no, the DC feed, for want of a better description comes from the excite side of the alternator that is driven by the engine. ITs only a handfull (8-10) of amps. using this while your drawing other power can cause both he 12v and the 240v voltages to dip.

If you sling a battery charger off of the 240v you can push more amps if you need to. I used to use a cheap 700w genset to drive my 30A oldschool battery charger and it used to do so quiet well, reasonably quietly and while running a couple of small 240v lights.


From what I remember from a conversation with a Tech the reason some switchmode power supplies don't like running off of square or modified wave power is because the change over in the voltages is too harsh and sudden, sort of like slamming your shift from 1st to reverse without backing off of the throttle or easing up on the clutch, sure you can do it for a while but eventually somethings gunna give.

I suspect that this is likely to be an issue with the use of triacs (SCR based devices) I am not a switchmode supply designer so am happy to be corrected.

[Blknight.aus]

could be I just know that we've been told not to hook up the dell laptops to the enviro gensets. the tech then splurged off into wavery electron flow talkity and more or less lost me after "you dont do it beacuse"

but that's ok, he was later confused as to why it wouldn't re-start when he'd filled it up with diesel.

[isuzu110]

I have successfully run a jaycar 16A 3-stage charger off a scorpion AVR style generator. Just run 200W of incandescent lightbulbs as well to give it some load.