Chorehorse charging question

[Jordan Baker]

Hi all

I was using my Chorehorse generators to charge up a 12v automotive battery yesterday. The ammeter needle goes right over to the “charge” side when I turn the charging rate knob to the right. After about 5-7mins the engine starts to slow down in RPM somewhat and then gradually the needle moves to the discharge side on the ammeter.

The Chorehorse is a 12v one.

I’m presuming that when the generator slows down somewhat and the needle moves to the discharge side, the battery voltage is now more then what the generator is putting out? Would this then mean my 12v battery is now charged up?

[charlie fitton]

A quick answer would be to test the battery - preferably with a hydrometer.

Even a voltmeter check before, during and after will tell you much.

Edit: and when it does go to the negative side, and you disconnect the battery, does the chore hose run normally? Careful of sparks!!! Explosion hazard!

[Chris Suslowicz]

I'd be inclined to (cautiously) check the Chorehorse out first.

Start with the oil level.

If it's overheating and slows down to the point that the battery voltage is greater than the generator output, the battery will start driving the Chorehorse generator as a motor.

What happens if you run the Chorehorse on no load, or use a couple of headlamp bulbs as a load?

It could be lack of lubrication (with a risk of the bearing seizing up) or fuel starvation - is the insulating gasket between the carburettor and engine block in place (depends on the carburettor, I can't remember if they're floatless suction types or not). Is the air vent on the fuel tank open to prevent a vacuum forming?

Best regards,
Chris.

[Jordan Baker]

The Chorehorse is all restored with all new fluids.

Yes I did make sure the air vent is open.

I do have to say that the battery was charged up. I did not have a volt meter to check the battery as it was being charged. The setup was on my Wire3 truck and running through the charging board as well.

[David Dunlop]

Hi Jordan.

The first thing I would check is if the Governor in the Chorehorse is working properly. It is one of those internal, set at the factory, do not play with items, designed to keep the Chorehorse running at a constant 2,200 rpm as the charging load varies.

Best way to test is start the Chorehorse and let it warm up with no load attached and put an rpm gauge on the end of the shaft to see what you get. Then repeat with a battery hooked up that needs charging and see if the Chorehorse is able to compensate via the governor to maintain the 2,200 rpm.

If that all checks out, you will need to monitor Ammeter readings to actual charging performance while the Chorehorse is running. To do this you will need a good quality hydrometer, ideally one properly scaled and also having red/yellow green warning sections on the scale. You cannot rely on a voltmeter to do this check. A 12-volt battery at 20% capacity will still show 12-volts output, but try and power anything with that battery and it will be dead in minutes, if not seconds.

Take a good 12-volt battery that is showing a relatively consistent hydrometer reading across all cells as close to midrange as possible. Low yellow to high red zone on the scale. The battery needs enough power to start the Chorehorse. Leave the caps loose on the cells. With the Chorehorse running, adjust the output for maximum deflection to the right on the ammeter and monitor the meter until you see the needle centre, then check the cell readings with the hydrometer. You should see a noticeable improvement and the Chorehorse rpm should have remained relatively constant in the process.

David

[rob love]

I have seen two people reference the hydrometers in this thread. There are now smart chargers, pulse chargers, the portable load bank testers (aka the toaster), inductive ammeters, and a host of other testing and charging devices. In my opinion, there is nothing that gives you an immediate condition report on a battery like the hydrometer. It will also tell you, with the first test, if a battery is worthwhile even trying to charge. Pulse chargers can remove a certain amount of sulphation in a battery, but when you have 5 cells in the green/yellow, and one way down in the red with black/brown electrolyte, it aint coming back.



When I was in Afghanistan the first time, I had a great team of civilian heavy duty mechanics. I remember having to show some of them how a hydrometer worked.

[Mike K]

Originally Posted by Jordan Baker

Hi all

I was using my Chorehorse generators to charge up a 12v automotive battery yesterday. The ammeter needle goes right over to the “charge” side when I turn the charging rate knob to the right. After about 5-7mins the engine starts to slow down in RPM somewhat and then gradually the needle moves to the discharge side on the ammeter.

The Chorehorse is a 12v one.

I’m presuming that when the generator slows down somewhat and the needle moves to the discharge side, the battery voltage is now more then what the generator is putting out? Would this then mean my 12v battery is now charged up?

Hi Jordan

In electrical terms the Chorehorse is a crude 'constant current' generator - it has no voltage regulation circuits i.e it will not adjust or regulate its power output to compensate for a varying load. If you walk away and leave a Chorehorse charging a car battery for an extended period , the battery can overheat and cook itself . The electrolyte will slowly boil away until it is all gone. In normal use, the RPM will drop with a increased load but that's a function of the physics involved in the armature windings and field coils.

When charging a car battery , you have to continually manually adjust the wire wound current control potentiometer to achieve a safe amps output level. The engine mechanical governor is just there to keep the rpm constant, as the engine slows with a increased load, the governor opens up the throttle to try and overcome the load.

We were on a club trip years ago and Bevan had his Chorehorse setup , it was charging my 22 set radio battery, we had the current output set high and after an hour or so the battery got rather hot - too much current flowing !

I would agree with Chris, sounds like there is a internal problem with Jordan's Chorehorse . The ammeter needle should not move to the Negative side , sounds like the battery is reverse charging the Chorehorse !

As for hydrometers , the cheap auto store types I've had no luck with them . They are a temperature dependent instrument, here is a write up https://www.usbattery.com/take-cold-...y-performance/