PCUK
Well-known member
As no one seems to make charging generators anymore and the DC output from suit case generators is very low I wondered what would be the smallest generator that it would be possible to run a standard battery charger from?
Generator question
- Thread starter PCUK
- Start date
RichardS
N/A
The Honda EU10i is fine for charging batteries through a mains charger. It's also the smallest, lightest and quietest portable gennie ..... but not the cheapest. 
I have an EU20i but unless you have a very large battery bank and want to heat water using an immersion heater it's probably overkill.
Richard
I have an EU20i but unless you have a very large battery bank and want to heat water using an immersion heater it's probably overkill.
Richard
lw395
Well-known member
I've got one of those nasty chinese 700w two stroke jobs.
I have used it with some 10A battery chargers, but I'd only use chargers which accept a wide voltage input range. It was running some lights at the same time.
I would suspect the volts might go up a bit when too lightly loaded.
I have used it with some 10A battery chargers, but I'd only use chargers which accept a wide voltage input range. It was running some lights at the same time.
I would suspect the volts might go up a bit when too lightly loaded.
macd
Active member
Not sure what the DC output has to do with it, since you're presumably looking at a mains-type charger.
Equally, I'm not sure what constitutes a 'standard charger'.
That said, 240V-powered chargers vary considerably in efficiency, so you'd need to check the spec of any particular one. Any reputable charger should specify the current it requires. If efficiency is 50%, you might expect a 1kW gennie to power something like a 40A charger, but I've encountered a couple that won't. It will also vary with the required start-up current and whatever the generator's transient peak ability might be. As a ballpark figure, I'd suggest that most 1kW gennies should handle most 30A chargers, although I'll happily to demur to anyone with a different experience.
Mistroma
Well-known member
Very much what I was thinking earlier today but train left station right on schedule and blatted up to 180mph before I had time to reply.
I seem to remember that my charger is about 70% efficient and 40A at approx. 13.5V (ish) is therefore about 770W from generator (40x13.5/0.7). Very rough figure but Honda EU10i should be OK for that. Some headroom to allow for possible initial surge as you say but I don't think that's a huge issue with chargers. I'd agree that 30A would be a safe bet for 1kW generators and 40A would probably be fine but you might just be unlucky with combination of some generators with certain chargers.
One other point is that some manufacturers quote peak output and then in small print give continuous output figure which is a LOT lower. I seem to remember that small Honda is pretty good in that respect and is probably around 900W.
OP didn't give much information as guidance (charger size and even battery bank size would have been useful).
Last edited:
Richard10002
Well-known member
My Eu20i happily runs an 80A charger.
lw395
Well-known member
I'd be more concerned about a small charger being too small a load for a poorly regulated generator.
Particularly a charger designed to see 230V only.
You might get more volts than you expect from a simple basic transformer type charger.
Particularly a charger designed to see 230V only.
You might get more volts than you expect from a simple basic transformer type charger.
PCUK
Well-known member
Looks like it'll be the little Honda then. Then a decent battery charger! Thanks all.
KevB
Active member
Petrol/lpg battery charger available still.
https://www.ebay.co.uk/itm/SALE-LPG-PORTABLE-GENERATOR-50AMP-12v-BATTERY-CHARGER-MOTORHOME-CARAVAN-BOAT/202222044036?hash=item2f155f8384:g:JYkAAOxygo9Q4AFB
https://www.ebay.co.uk/itm/SALE-LPG-PORTABLE-GENERATOR-50AMP-12v-BATTERY-CHARGER-MOTORHOME-CARAVAN-BOAT/202222044036?hash=item2f155f8384:g:JYkAAOxygo9Q4AFB
PCUK
Well-known member
That looks ideal and the price on their website is a lot better than Ebay. I'm tempted!
macd
Active member
Whatever its other merits or demerits, I'd want to be sure that its voltage regulation suits whatever batteries you have or may have in the future. As I'm sure you're aware, a 240V gennie is more versatile and probably more future-proof (always assuming it lasts long enough
)
Muddy32
Member
Suitcase generators - beware cheap LTS chinese imports- cheap for a reason.
No further comment as legal negotiations taking place.
No further comment as legal negotiations taking place.
steve66
N/A
I have a little Clarke genny for sale in the for sale section, fully serviced with battery charging terminals if your interested?
Iliade
Well-known member
Aren't a lot of modern gennies inverter types? This would imply that their initial output is low voltage. Maybe 12V?
anniebray
Member
The Honda EU10i is fine for charging batteries through a mains charger. It's also the smallest, lightest and quietest portable gennie ..... but not the cheapest.
I have an EU20i but unless you have a very large battery bank and want to heat water using an immersion heater it's probably overkill.
Richard
I have the Honda EU10i & it just about manages my 40A mains charger. It has a DC output of 8A. I was tempted to get the EU20i so I could run my 800w Microwave (1 Kw generator is insufficient) but decided against due to size & weight on my 9m yacht. Don't laugh about the microwave, I had it built in from new & it's served me well in France, Spain & Portugal where its most common to have mains supply at no extra charge.
solent clown
RIP
These are a good little genny for the money, very small and lightweight, and quiet too. They do however die if you drop them in the water... Don't ask
https://www.screwfix.com/p/impax-im...gclsrc=aw.ds&dclid=CJ7BsZPQu9kCFU1xGwodissOeA
https://www.screwfix.com/p/impax-im...gclsrc=aw.ds&dclid=CJ7BsZPQu9kCFU1xGwodissOeA
RichardS
N/A
I certainly won't be laughing because I'll admit that I've occasionally timed the running of my EU20i to first charge the batteries, then heat both water tanks, then finish off by heating a bowl of soup in the microwave. I can then eat the soup, have a shower, and turn on the lights as, by then, night is falling.
Richard
GrahamM376
New member
A lot of money for something which could be built for £100 or less with an old lawnmower engine + scrapyard alternator.
PCUK
Well-known member
Now I'm undecided again!
solent clown
RIP
that is what we did, old diesel cement mixer engine and an alternator, works a treat. Engine charges its own battery too!
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