Is 12amps output sufficient ?

[Sibbo]

Is 12 amps output sufficient to run lights plus recharge the battery on a simple Enfield with a clone 10hp diesel ?

This engine is being offered on local Ebay http://cgi.ebay.com.au/ws/eBayISAPI.dll ... TQ:AU:1123 and the seller says the charge output is 12 amps .It's not much but perhaps enough ?

[DieselFly]

Looks just the same as the Yanclones I get here in Canada. If that is true it will put out about 2 amps at 12.5volts. The current will charge the battery okay but the voltage is to low. Voltage needs to be 13.5-14.25 to charge properly. I have a regulator from a GS550 hooked to the original coil on my bike. I get about 5 amps which is just enough. My voltage tops out just short of 14 volts. All I can say is it works. Tundercougerfalconbird has a nice section on rewinding the charging coil for more current

Sean

[pietenpol2002]

Just an aside. When looking at the link for that engine it references ball bearings on both ends of the crank. When did that change occur or is it unique to theirs. Suppliers of new cranks for that engine here in the state only offer them with ball bearings on the PTO end.

[Sibbo]

Just an aside. When looking at the link for that engine it references ball bearings on both ends of the crank. When did that change occur or is it unique to theirs. Suppliers of new cranks for that engine here in the state only offer them with ball bearings on the PTO end.

Yep , that appears to be a significant difference . The seller said 12 amps output too ...not 2 amps .

[Diesel Dave]

I run a 4 amp alternator - works fine.

Of course it only has to power the headlamp and charge the battery a little, all the other bulbs are LED.

I just use a rectifier and rely on the battery holding the voltage down, been working for 2 years without a hitch.

[oldbmw]

bet the seller means 12 volts

I just bought a log splitter having been told the motor was 3Kw, after I unpacked it I discover it needs a 4Kw supply, ( 17 amps constant, a lot more when starting)

now to rewire the barn ( and house)

[XLerate]

bet the seller means 12 volts

I just bought a log splitter having been told the motor was 3Kw, after I unpacked it I discover it needs a 4Kw supply, ( 17 amps constant, a lot more when starting)

now to rewire the barn ( and house)

Aren't you guys in France on 220VAC @ 50 cycles? You should have enough power through a 20 Amp breaker according to Ohms Law: Watts divided by Volts equals Amps:

4,000 Watts divided by 220 Volts = 18.18 Amps. So a 20 Amp breaker on 220 Volts supply should cover it. Amps X Volts = Watts, so then 20 Amps x 220VAC = 4,400 Watts [4Kw]. Maybe talk to a local electrician?

[thundercougarfalconbird]

the manual that came with my engine says it has a 15 amp charging system, they seem to print and say anything in the manuals, 12 amps might work for you, depending on how many lights you have on the bike, the main consumer is the headlight, everything else can be L.E.D.

as long as you can maintain 14.5 volts while running it should be fine, you may end up changing the regulator, the chinese ones seem to be low on voltage output.

[oldbmw]

bet the seller means 12 volts

I just bought a log splitter having been told the motor was 3Kw, after I unpacked it I discover it needs a 4Kw supply, ( 17 amps constant, a lot more when starting)

now to rewire the barn ( and house)

Aren't you guys in France on 220VAC @ 50 cycles? You should have enough power through a 20 Amp breaker according to Ohms Law: Watts divided by Volts equals Amps:

4,000 Watts divided by 220 Volts = 18.18 Amps. So a 20 Amp breaker on 220 Volts supply should cover it. Amps X Volts = Watts, so then 20 Amps x 220VAC = 4,400 Watts [4Kw]. Maybe talk to a local electrician?

when working with AC, Ohms law needs to be looked at a little deeper.
first our power is nominally 230 ac +-10%
the standard plug circuit here takes 16 amp ( about 3600 watts max). ( UK 13 amps) not 20.
The run to the barn is about 35 yards so you need to watch the volts drop. The wiring to the barn is barely capable of supporting this.
The device is a 5 hp motor which is an inductive load , so until it is up to speed it will take several times more than the 4 kw it needs to run
Being inductive it will greatly affect the power factor and your resulting current flow will be disproportionately greater than the expected.
Not until the motor is up to speed will it generate enough back emf to reduce the current to its normal 17 amps running.
worse, the motor has to start against a load ( the hydraulics pump), the likelihood is it wont be able to get up to speed unless it has a good power source so will be stuck in start mode pulling way over 50 amps.
In this type of scenario it is very easy to get into an uncontrolled feedback loop. the current wiring is 2.5 mm sq cable which can carry the current when running in theory (20 amp cable). BUT. it will be pulling 17 amps and would probably overun the current 15 amp fuse (not 16 due to previous owner wiring it incorrectly). Add to this the the run from consumer unit to device is nearer 50 yards, the volts drop running would be about 10 volts which reduces power by about 5% so would increase current by the same amount. this is where Ohms law becomes complicated as it is not Ohms we need but inductance, on startup the volts drop is severe (30-60 volts), easily enough to prevent the motor from starting and then it will just fail, hopefully with fuse blowing. This is the initial drop, as soon as the wire starts to heat up it will increase. Because of this I will run a 6mm sq cable (+40 amp) to make a new supply to the barn. This should allow the motor to start against a load.
To give an example of currents required, I have a Brooks 2 hp motor on my lathe. now 1 hp = 736 watts, but it will blow a 13 amp fuse if I try to start it offload. for that I had to install a heavy duty circuit. this 5 hp motor against a load will be much more difficult.

[XLerate]

Giving the rest of the info does help, thanks. Only info posted was: "I just bought a log splitter having been told the motor was 3Kw, after I unpacked it I discover it needs a 4Kw supply, ( 17 amps constant, a lot more when starting)" so I went with that.

[snoopy]

The original stator behind the flywheel typically gives 6 to 40v DC once rectified and about 80W total (so 2A max).

Using a couple switch mode convertors on ebay (parallel them) you can get 14v at 5+ amp no problem with 90% efficiency. This is how I went about it.

No point rewinding it, you'll only get a tradeoff for amps/volts.

[Stuart]

Had to return a new car alternator recently as it just wasn't delivering. They tested it before refunding our money. Before that we'd got a recon unit from the breakers and that too was only working at 80%.
Dodgy regulators? Or components? Be careful out there