Petrol Generator

[mark1882]

I am thinking of buying a petrol generator for emergency charging of the batteries as part of our preparation for going to the med in May. I am looking at suitcase type chargers and was originally looking at the Honda ones bit have recently come across Kipor brand which are about half the price of the Honda. I have 4 x 100a domestic bank and a 100a engine start battery, so I have two queries where I would welcome some advice from forum members.

1)What size of charger in terms of output should I buy.

2) has anyone any experience of the Kipor brand.

Thanks

Mark

 

[rivonia]

Get a Honda 2KW brilliant and quite. Your neighbors will appreciate that.

 

[Tony Cross]

Get a Honda 2KW brilliant and quite. Your neighbors will appreciate that.

+1

I have the same model, very pleased with it.

 

[TQA]

How big a charger do you have? If it is up to 50 amps then a !000w generator will do. Anything more and the 1kw will struggle.

How often do you see yourself using it ? If it is more than a once a year emergency THEN BUY A HONDA! You and the rest of the anchorage will appreciate how quiet they are.

 

[Mistroma]

I'm afraid that I can't help you choose between Kipor & Honda (or other brands)

Get as much solar as possible, reduce usage as much as possible and then look at ways to make up any shortfall (almost guarantee there will be a shortfall). Wind usually won't be a solution, just helps a bit. I don't like running the engine at anchor so we still have a shortfall when stopped for several days.

That makes a generator almost essential and I went for a Honda EU20i for noise & reliability reasons. Honda used to be proactive in keeping prices up and I wouldn't be surprised if they "were happy to see" rumours about reliability of cheaper brands. However, I wanted reliability and that's what I've had so far.

Following might help:
1) Ignore the headline output, use the continuous output. ~1.6kVA (EU20i) & ~0.9kVA (10EUi)

2) Work out what you might use it for
40A charger could be drawing around 0.7kw when feeding a pretty flat battery bank
My water heater is rated at 1.2kw
Toaster is 0.8kw
Microwave (800W) takes about 1.2kw
Most of above have power factors of 1 (or very close to it). My microwave takes about 25% longer to cook things vs. times on mains power

So I can charge a battery and make toast OR Use microwave and charger when batteries are about 75% charged etc.
Electric kettle isn't used (2.3kW) nor electric cooker (though I could run either of 2 elements individually). Gas makes more sense for these at anchor.

The EU10i would be fine just for battery charging but wouldn't cope with my microwave.

3) Consider alternatives for some devices
Water heating is the most obvious one. I can't remember the exact figures but I did work them out from theory and seem to remember getting 1.5 - 2 hours to heat a tank of water from ambient to normal cutoff temp. I think that I can get away with slightly less time but very, very rarely use the generator to heat water. Solar showers do the trick and work very well as they dangle from sprayhood right into the aft. shower compartment.

Look for low wattage devices likely to be used at anchor and balance reduced performance with freedom to use whenever you like. We have iron, toaster, microwave, electric hob etc. available at anchor. Not always used, but useful to know that we can cook something if the gas runs out.

Hopefully, this helps you to pick an appropriate generator from a range and use output, price, weight, reliability etc. to choose one.

 

[ribrage]

E

Get a Honda 2KW brilliant and quite. Your neighbors will appreciate that.

yep , what he said ^|^|^|^

 

[crisjones]

We have a Kipor 2.6kW and it works exactly as you would expect for less than half the price of the equivalent Honda. It probably is a bit noisier than a Honda but it is very easy to only run it when you will not annoy your neighbors. Even a "quiet" Honda is annoying at the wrong time!!!

If you are only likely to use the generator occasionally (as we do) then the Kipor will be more than adequate, if you expect to need to run it 2 or 3 times a week for an hour or more then the Honda may be the better option - but remember you can buy at least 2 Kipor's or their equivalent in almost any discount DIY store throughout Europe.

I am perfectly happy with my choice of the Kipor and I could not justify the cost of the Honda for our usage.

Also it is worth pointing out that water heating in the summer in the Med is a bit of a misnomer - you do not need hot showers and washing up can be done with a kettle full of water, you certainly do not need to worry about power requirements for hot water unless you really want 5* luxury on your boat

 

[PhilipH]

We have the 1kw Honda - it is great too and the dry weight is 13kg vs 21kg for the 2kw. Sorry we didn't buy one earlier.

 

[GrahamM376]

Whichever you go for, get 2kw as it will run microwave and lots more. We went for Honda as service and parts available virtually everywhere, not sure about the Kipor.

As chrisjones says, water heating not often necessary, we also boil kettle for washing up and use camping showers, which sometimes need cold water adding, occasionally warm up from kettle if late in the evening and they've cooled down.

We rarely use the genny as solar and Aerogen take care of our needs unless no sun for a few days which doesn't often happen.

 

[macd]

Worth noting, since only Kipor and Honda have been mentioned by name, that the smaller Kipors are Honda replicas which used to be made under licence. Their vital statistics are almost identical, including noise. I understand that the license is now long expired, but Kipor continue to make and sell them. They're probably the best small generators not bearing 'name' brands.

Re: battery charging: double-check the spex of your charger before choosing a genny. A 1kw genny should cope with a 40 or even 50A charger, but it won't always.

 

[Mistroma]

I suppose that we do not actually need hot showers, but wouldn't like to be stuck with cold showers. But I do find solar showers more than adequate and that's what we actually use. I have met a few people who said they used their Honda for hot water, so mentioned it in case you were considering it. I have to say that it is a pretty poor way to use the generator, takes ages on full throttle and so quite noisy even with a Honda.

One point I missed was that you said "for emergency charging of the batteries ". Pretty good chance it will get a lot more use than that unless you have a lot of solar. I often run ours every 2nd or 3rd day at anchor for 1-2 hours (usually 1). If I could only squeeze in a little more solar then I could stretch that out. However, I'd still end up using a bit early and end of season.

What's the quoted output of your solar panels? They can be a real game changer if you can fit enough. Upgrades to other charging sources become much less important type and size of battery becomes less important as well. A surfeit of solar power means that you only need enough battery capacity to manage overnight. The catch is having enough space to fit the panels. I know that's the way I need to go but can't quite get there.

 

[charles_reed]

I suppose that we do not actually need hot showers, but wouldn't like to be stuck with cold showers. But I do find solar showers more than adequate and that's what we actually use. I have met a few people who said they used their Honda for hot water, so mentioned it in case you were considering it. I have to say that it is a pretty poor way to use the generator, takes ages on full throttle and so quite noisy even with a Honda.

One point I missed was that you said "for emergency charging of the batteries ". Pretty good chance it will get a lot more use than that unless you have a lot of solar. I often run ours every 2nd or 3rd day at anchor for 1-2 hours (usually 1). If I could only squeeze in a little more solar then I could stretch that out. However, I'd still end up using a bit early and end of season.

What's the quoted output of your solar panels? They can be a real game changer if you can fit enough. Upgrades to other charging sources become much less important type and size of battery becomes less important as well. A surfeit of solar power means that you only need enough battery capacity to manage overnight. The catch is having enough space to fit the panels. I know that's the way I need to go but can't quite get there.

IMHO solar a far better route to go - the drawback is having insufficient area on the average boat. I have 328w and find myself completely independent of any other charging sources during May-August, in Greek waters.
Hot water from running the engine 20' gives me really pleasant showers for the next 24 hours. Usually you need the engine for lifting and dropping the anchor.

 

[Mistroma]

IMHO solar a far better route to go - the drawback is having insufficient area on the average boat. I have 328w and find myself completely independent of any other charging sources during May-August, in Greek waters.
Hot water from running the engine 20' gives me really pleasant showers for the next 24 hours. Usually you need the engine for lifting and dropping the anchor.

Got to agree, it's nice to have hot water via the engine. We have a mixer valve and engine gets the tank much hotter than via immersion heater (prob. has a very conservative cut-off setting). However, we often stay in one place for several days and that's when we fall back to solar showers as engine has not been run.

I'd love to fit another 2x50W panels which would relegate the generator to backup. However, finding enough space is the problem as you say.

 

[Budgieboy]

Hi All ..... this is going to sound stupid , do you just plug these units into the boats shore lead socket ? .....

 

[GrahamM376]

Hi All ..... this is going to sound stupid , do you just plug these units into the boats shore lead socket ? .....

Yes, that way power goes via the on board rcd. If for some reason I use it direct, I use a plug-in rcd.

 

[mark1882]

Hi
Many thanks for a very helpful response particularly as I currently have a very old 50A charger and am thinking of changing it for a 70A so I am very interested in the relationship between the output of the petrol generator and the amperage of the charger.

Would you please help me understand why this relationship is so important and what the calculation is ( if there is one) for working this out.

Many thanks

Mark

 

[duncan99210]

OK. Your present charger delivers 50 amps at a nominal 12 volts to your batteries. If you multiply the amps by the volts, it will give you how many watts are being used: in this case 600 watts. If you fit a 70 amp charger, it will use 12 multiplied by 70, ie 840 watts.

Right that's how much power your charger is consuming to produce the output to the batteries. Clearly, you need to. put at least that much power into the charger in order to get it to the batteries. In practice there are losses in the charger which will require the input of more power than the raw figures suggest. 700 watts for your present charger and 950 watts for the proposed 70amp charger would be reasonable.

If you now look at the power outputs of the generators you are considering, there are two,power ratings 1000 watts and 2000 watts. If you stick with your present charger, then the smaller one would be fine: up it to 70 amps and it'd be marginal for the 1000 watt generator and you'd do well to getting the 2000 watt one.

Your charger will not work at all if the generator is not producing enough power, it's protective circuits will sense the overload and cut out to protect it. In addition, if you have a marginal generator, it will be working flat out to charge the batteries and will tend to overheat. No problem in UK where ambient temperature are typically 20 degrees or more less than the thermal cutoff value, not so good in the Med where the ambient temperature can often only be 10 degrees less.

A final point. Generator power is often expressed as peak load and normal load. The peak load is the load a piece of equipment has as it starts up: this can be quite high for kit with motors in it, less so for things like chargers. The normal,load is what you can expect the generator to provide over a prolonged period. The Kipor IG1000P for example has a peak output of 1000 watts but a sustained load capability of 900 watts and is marketed as an 800 watt generator.

 

[Mistroma]

OK. Your present charger delivers 50 amps at a nominal 12 volts to your batteries. If you multiply the amps by the volts, it will give you how many watts are being used: in this case 600 watts. If you fit a 70 amp charger, it will use 12 multiplied by 70, ie 840 watts.

Right that's how much power your charger is consuming to produce the output to the batteries. Clearly, you need to. put at least that much power into the charger in order to get it to the batteries. In practice there are losses in the charger which will require the input of more power than the raw figures suggest. 700 watts for your present charger and 950 watts for the proposed 70amp charger would be reasonable.

If you now look at the power outputs of the generators you are considering, there are two,power ratings 1000 watts and 2000 watts. If you stick with your present charger, then the smaller one would be fine: up it to 70 amps and it'd be marginal for the 1000 watt generator and you'd do well to getting the 2000 watt one.

Your charger will not work at all if the generator is not producing enough power, it's protective circuits will sense the overload and cut out to protect it. In addition, if you have a marginal generator, it will be working flat out to charge the batteries and will tend to overheat. No problem in UK where ambient temperature are typically 20 degrees or more less than the thermal cutoff value, not so good in the Med where the ambient temperature can often only be 10 degrees less.

A final point. Generator power is often expressed as peak load and normal load. The peak load is the load a piece of equipment has as it starts up: this can be quite high for kit with motors in it, less so for things like chargers. The normal,load is what you can expect the generator to provide over a prolonged period. The Kipor IG1000P for example has a peak output of 1000 watts but a sustained load capability of 900 watts and is marketed as an 800 watt generator.

Estimate might be a bit low as battery will be charging at more than 12V. e.g. 14.4V x 70A gives 1008W.
I used to estimate efficiency at around 83% for chargers if I didn't have model & specs. to hand.
That would boost requirements to 1215W from the generator (too much for a 1000W generator, even if that was the cont. output figure)
I see that you used a figure of approx. 88% for charger efficiency. Have things improved recently, I haven't checked charger specs. for a couple of years?

 

[duncan99210]

Mistroma, you've mistaken me for someone indulging in exact workings out: all of the above figures are 'about' figures used to illustrate the link between watts, amps and volts for Mike who clearly didn't quite understand the linkage between the various figures being bandied about. You are of course correct about higher charging voltages etc. I have no idea about the efficiencies of current chargers v older ones, I was simply quoting some figures so that Mike could understand that he would need to look at the specifications of the various options under consideration, both in terms of chargers and generators so that he could match them up and not wind up with a charger requiring more output than the generator he bought....

 

[maxi77]

Worth noting, since only Kipor and Honda have been mentioned by name, that the smaller Kipors are Honda replicas which used to be made under licence. Their vital statistics are almost identical, including noise. I understand that the license is now long expired, but Kipor continue to make and sell them. They're probably the best small generators not bearing 'name' brands.

Re: battery charging: double-check the spex of your charger before choosing a genny. A 1kw genny should cope with a 40 or even 50A charger, but it won't always.

Honda did take action against Kipor a few years back and I belive a big batch was embargoed. The current one do not infringe any Honda patents as far as Iam aware and in general seem pretty reliable. I sold my 2.6 to a mate a few years ago and he is still a mate and my 800 watt one worksperfectly every time I use it even with old fuel in it. Certainly worth the money.