12v generators

does it harm batteries to charge them that fast?and could you run the genny straight through an inverter to make 240v?
 
I personally would not want to charge my batteries at anything over 20 amps (and that is 2 x 110 ah batteries). It is my belief that this will shorten the battery life. Without examining the technical details, I would not want to comment further, except to say that the battery condition dictates the rate of charge and not the power of the charging unit.
 
maingate said:
I personally would not want to charge my batteries at anything over 20 amps (and that is 2 x 110 ah batteries). It is my belief that this will shorten the battery life. Without examining the technical details, I would not want to comment further, except to say that the battery condition dictates the rate of charge and not the power of the charging unit.
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Vehicle alternators can charge at a similar rate the tailing off of the rate is the important thing?
So long as the batt is charged rapidly to within say 80% of its life and then gradually the rate reduces to full charge, that should be ok in other words properly regulated charging.
I haven't read the specs for this generator.
 
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Tbear said:
Surely the heat created by charging at 50amps will just boil a battery. Imagine trying it on a 60amp battery.

Richard
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Many car/van alternators shove out 50+ Amps the battery doesn't boil because the alternator puts out much less Amperage as the battery Voltage rises (Voltage sensing) long before it gets hot.
I connected a cheap 4A charger on a battry once and forgot about it. A day or two later I checked and found the battery acid boiling, the 4A charger had no means of reducing its charge rate.
 
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its not new. the off road boys in oz and the states have been using them for years . byronic is correct it charges rapid to start with but soon drops down to a small charge . just like your car alternator . biyt of trick working out on there item i think. they are very good at starting a flat battery . its possible they come up in the 4x4 mags occasionaly. seems a bit pricey to me . but then they do work in those off road situations .
 
Byronic said:
Many car/van alternators shove out 50+ Amps the battery doesn't boil because the alternator puts out much less Amperage as the battery Voltage rises (Voltage sensing) long before it gets hot.
I connected a cheap 4A charger on a battry once and forgot about it. A day or two later I checked and found the battery acid boiling, the 4A charger had no means of reducing its charge rate.
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It claims to charge a 70amp battery 50% discharged in 42mins. Does not sound like it cuts back the power much.
 
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Tbear said:
It claims to charge a 70amp battery 50% discharged in 42mins. Does not sound like it cuts back the power much.
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But does it charge to 100% if you had a graph of its performance you will probably find it charges to 90% in say 30 minutes then the last 10% in 15 minutes not in steps of course but as gradient possibly exponentially eg first 2A takes 4 minutes the next 2A takes 16 minutes etc or sinusoidally.
 
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Byronic said:
But does it charge to 100% if you had a graph of its performance you will probably find it charges to 90% in say 30 minutes then the last 10% in 15 minutes not in steps of course but as gradient possibly exponentially eg first 2A takes 4 minutes the next 2A takes 16 minutes etc or sinusoidally.
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I am sure the charge it will take will drop off as it reaches maximum but whether this is because this thing has a built in smart charger or because thats what the battery will take. So I'm an old cynic but I would not want to leave it running too long on my batteries
 
Tbear said:
I am sure the charge it will take will drop off as it reaches maximum but whether this is because this thing has a built in smart charger or because thats what the battery will take. So I'm an old cynic but I would not want to leave it running too long on my batteries
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Tbear, apart from what is written in the replies I don't really know what this generator is about. I'm presuming it incorporates a smart or intelligent 12V charger, how smart or how intelligent?
So without a full spec I would take the same view as yourself.
 
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hi normally just a normal car type set up. you can get 90amp alternators standard on lots of cars /vans these days .
 
Bigpeetee said:
Much as I don't like generators, this one generates directly at 12v at up to 50A, uses a 4 stroke engine and is quite light.

Not cheap, but more efficient.

Your thoughts? Anyone seen these at shows??

PORTABLE 50 AMP 12 VOLT BATTERY CHARGER MARINE BOAT MOTORHOME CARAVAN | eBay
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Well, I'm not an expert but..It seems pretty obvious to look at that this is simply a strimmer type motor bolted straight to a car alternator, with an ammeter added for, err good, measure. The 'smart charging' bit is integral to most modern alternators. I'd say that it would cost your average car mechanic lass than £100 to build. It's not a bad idea, but I think some of the maths stated is a bit dodgy.

The problem arises, I think, with the difference between a leisure battery and an ordinary car battery. First consider the fact that batteries like to be recharged the same way that they are discharged. A car battery is designed to provide a massive amount of power in one short hit in order to start your engine, then to provide a bit of power ongoing. Your car alternator is designed to recharge in the same way, a big hit first off to get the battery back up to almost full power ASAP in case the next time you want to start comes along very soon. BUT, your leisure battery is designed to provide long term steady power, just as your usual mains leisure battery chargers are designed to do when charging.

So that's why, again I think, the likes of mighty Honda build what they build so successfully - and why this is being knocked up in a back shed and punted to us on eBay. I'd buy the cheap Honda copy that somebody else recommended. I've got a genuine EU20i and it's just fine.

But, could be I've got it all wrong and this is a genius idea.
 
I would prefer a 240v generator as can run fan heaters, fridges, mini ovens and power tools direct from it. More versatile.
 
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