opinions on charge regulation, 13 HP B&S

[Simen]

I got a lawn mower rider (Jonsered JICTH13A) which has an unregulated 3 A charge output.

The coil inside the flywheel has one end connected to chassis, and the other end are connected to the battery, via a single diode.
The Open AC Voltage are rated to 28 V @ 3600 rpm.

I use the rider for around 2 hours, 1-2 times a week from early spring to late autumn, and at the end of the season, the (new in spring) battery are usually more or less shot. (The battery are a 12 V, 20 Ah LA)

I do have a regulator from another rider, but it has 2 AC inputs and a positive output, with negative on chassis. I could open the flywheel and disconnect the other end of the coil from chassis, and connect it to the regulator.

Or is there an easier way?

[MagnetJuice]

I think this is the Schematic Diagram for that Mower

[MagnetJuice]

Here is a better image

[joestue]

just get a used car battery for $5 from someone and use it instead of a new sealed lead acid.


old car batteries may be able to rejuvinated if you dump the electrolyte out and fill it with water, connect to a float charger at 13.8 volts or more for a month or two, and see if the water rises to say 1.2 specific gravity. if so, dump that out and put the original electrolyte back in. boil down the 1.2 SG electrolyte until its say, 1.5  and add it back to the battery as needed to get normal acid concentration.

[MattM]

I've always wondered if the tractor battery could be drained for storage.

When they sit they die over winter.  Actually had one make it 2.5 years, but most die in a year.

[Mary B]

I get 4-5 years out of a mower battery, and it sits all winter, BUT it never drops below about 28 degrees. When I went to fire it up this spring it started right up. I keep the top of the battery clean, that dust and debris holds moisture and can create a circuit that will drain the battery!

[MagnetJuice]

Those batteries should last longer than a year. I think that the battery is being overcharged by that unregulated alternator, getting it hot and reducing its life.

An inexpensive simple solution would be to place a 3 ohm, 25 or 30 watt power resistor in series with the battery. That would bring the voltage to about 18 volts going into the battery. That is better than the 26 volts that is going in without the resistor. I would clamp the resistor to a piece of metal (preferably aluminum) to absorb some of the heat.

That would be a crude solution, but it would work.

The battery should be removed before winter, cleaned and given a full charge, then kept in a warm place during the winter.

Ed

[MattM]

I'm in Florida these days so it may be the crud that literally coats everything each winter.  Pollen season is about six months a year.

[Simen]

Thanks MagnetJuice, i do have the schematics already. And yes - the battery are being overcharged each time i mow; that's why i want to regulate the charging. After 20-30 minutes runtime, i measure 15+ Volts while it's running... :-/

A resistor would be easy enough to implement.

But i think i'll see if i can get the flywheel off, to get both ends of the charging coil out, and see if the regulator i got (used) will work...

[MagnetJuice]

If you choose the option of the resistor, the only place to put it will be somewhere on the RED cable. That way you have the full power of the battery for starting the engine.



Ed

[Bruce S]

Not trying to hijack your thread, but is it strange there's a FBI Buzzer and Switch?
Or is it just me  .

Also;
You could find a regulator for car, IF I'm looking at the schematic correctly , it'll connect and regulate the wild AC down to the correct voltages. Since this is putting out 24VAC you may have to opt for a 24V unit , but a grease-n-go should have one. Our Ambulances use the 24V versions.

Bruce S

[Simen]

Bruce; the buzzer buzz when the collector bag are full - or used to; the sensor switch failed years ago, so i disconnected it... (Or did you refer to a certain investigative bureau? )

I would think that a car alternator puts out more than 28 V wild AC? Anyway, there isn't any field to regulate here?

[Bruce S]

Yes, I was referring to the bureau  .

The output is well regulated to hold 13.8 (IFR) . The regulator should not care about a field. It's more like a full-wave regulator that will take the wild AC and regulate it to smooth DC at 13.8Vdc.

Hope that helps.

Bruce S

[mab]

A simpler solution might be to add loads - say a couple of 12v 12w lamps on switches?

If the generator only outputs 3A then turning on a 12w lamp (1a load ) after a few minutes then another after another 10 mins should reduce the charge current to reasonable levels. I was going to suggest turning on the headlights after 5 mins but as they're on a separate output they might not affect the battery charge output.

[JW]

https://shop.advanceautoparts.com/p/driveworks-voltage-regulator-86073/11440163-p?c3ch=PLA&c3nid=11440163-P&adtype=pla&gclid=Cj0KCQjwuLPnBRDjARIsACDzGL2lvQzB1T3aG0qXBZsonDXlAIPCPYuXDkItPDq8m-g4DrlDccMmf_MaAjQwEALw_wcB&gclsrc=aw.ds

[JW]

https://shop.advanceautoparts.com/p/bwd-voltage-regulator-r156/20430130-p

[MagnetJuice]

Simen, this schematic looks very similar to yours. It is from a Craftsman Rider and has a regulator.


You have 28 volts AC coming out of the alternator, this Craftsman has 12 volts. If you place the regulator right after the alternator, that will reduce the voltage going to those relays. Most relays activate at a lower voltage than their rating, so maybe that won't be a problem.

I hope this helps.

Ed

[Simen]

I've actually just ordered a regulator that fits my coil/engine.

If you turn to page 21 in this document from Briggs and Stratton, you'll see there is a regulator option for my generator fitted with just one diode.

This regulator are not mentioned in the spare parts list for my mower...

[Simen]

Just to bring a happy ending this thread, i can tell you that i received the regulator a week after my last post.

I cleaned a spot on the chassis (with a grinder) to get a good negative connection, and mounted the regulator there, close to the connectors coming out from the flywheel - the connectors on the regulator was a perfect fit.


Now, after 15-20 minutes run time, i measure around 14.23 Volt - good enough...

[MagnetJuice]

Good to see a successful ending. Thank you for posting.

Ed