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Hey all,

I acquired a Briggs model 287707-0227-01 engine(14hp, I/C). I put it in my 36" commercial walk behind mower as the original Kawasaki engine decided to throw both valve seats. The kawasaki was pull start and the briggs is electric. I start it with a starter/charger I have that can roll out 200 amps for starting. I'm going to add a cheap lawn and garden battery but not sure how the charging system will affect the battery. The Briggs uses a single diode coming off the stator to charge the battery, not your typical voltage regulator. The battery will only be used to start the motor as there is nothing else electrical on the mower. I guess I'm wondering if the battery is charging while I'm using the mower if it can mess the battery up since the battery will probably not even really need to be charged. Hope this all makes sense. I know how to wire everything up. I'm just concerned about 'overcharging' I guess. I thought about just using a charging tender on the battery between cuts.

I should also mention this is for my own yard, not commercial. The mower is used once a week for 20-30 minutes. I thought about just using my charger/starter to keep starting it but if/when I have to cut the mower off while cutting lawn, or if it dies for some reason, I either have to push it back to garage or drag out the 100' extension cord to hook up the starter/charger.

For those wondering why not just fix the Kawasaki it's because there are very few parts available. I actually did fix the exhaust side at one point. Ran great for a minute then threw the intake seat. Thats when I found out there are very few parts available for the engine. The mower is 20+ years old. And I got the Briggs for free from my brother!

Thanks for any advice,
Ron

the single diode charging system is only putting out about the same amount as a float charger. 3 amp max. Since the engine is set up for it might as well connect it to the battery and let it recharge the battery while running to slightly replenish what was consumed with the electric start.

Copy that. Thanks!

wait..
first thing to do is check the voltage it is putting out.. to charge a 12v garden battery the voltage must be between 12.2 and 14.5 volts with 13.8 being perfect.. check it at highest and lowest rpms.. of course going too low at low rpm is fine as long as your running the mower not at the lowest rpm.. just mke sure it puts out at least 12.2 volts and no more then 14.5.. if it does the battery will be fine and dandy..

If you go over the 14.5 limit the worst thing that will happen is the battery will burn out after a few runns, if it sits consistantl below 12.2v the battery will never fully charge back up and would need a booster charge after 8 or 9 starts...

@mitchstein443 This is a non regulated 3 amp charging system mower. Not enough amps output to damage the battery. Actually there isn't enough output to recharge the battery after a start unless run like 5 hours. This type of system runs at a deficit for recharging the battery. Eventually it will run the battery down even with the charging system working properly.

IMHO, 3A should be fine if you run your mower for the usual 1+ hour of mowing per week.

The weakness in these low rate, unregulated systems is that there's no way to raise the charge rate when the battery gets in a low state. But there are things you can do that will insure a much higher success rate...

• Once you crank the mower, leave it running. DO NOT start and stop several times. Check the oil and air in the tires before cranking. When you finally crank the engine, be ready to run it for the duration. Leave it running while getting rocks and other obstacles out of the way. Simply maximize the charge time, while minimizing the drain (the number of starts).
• Keep your all battery cable terminals (both ends of BOTH cables) corrosion-free. Have the best electrical connections possible. This might call for treating the connections with electrician's anti-oxidation compound.
• Fit a battery switch so that the battery doesn't dis-charge while it's sitting. The one I use cost about $9 and does a beautiful job. CLICK HERE. There are 3 types of these for different battery post types: round post, side posts, and motorcycle.

Hope this helps.

ILENGINE said:

@mitchstein443 This is a non regulated 3 amp charging system mower. Not enough amps output to damage the battery. Actually there isn't enough output to recharge the battery after a start unless run like 5 hours. This type of system runs at a deficit for recharging the battery. Eventually it will run the battery down even with the charging system working properly.

Click to expand...

atually, 3amps is more then enough to charge the battery.. unless the battery is totally drained. for a siply turnkey start the battery will be fully recharged in under 10 minutes at 3 amps.. 30 minutes at 1 amp..
The battery will only absorb what amperage it needs to charge fully provided, the voltage does not exceed 14.5 volt.. If you put 20 volts into any 12 volt battery at just about any amperage you will shorten the life of the battery to next to nothing.. Trust me, I have done enough solar setups to know exactly hat goes on inside a lead acid battery and all thier tolerances.. best thing for a lead acid battery is a trickle charge at .25 amps over night.

A good example is a 50% discharged standard battery from a riding mower attached to a 10 amp regulated charger at 13.8 volts will only accept 2.5 amps to recharge.. so 3 is more then it needs...

mitchstein443 said:

atually, 3amps is more then enough to charge the battery.. unless the battery is totally drained. for a siply turnkey start the battery will be fully recharged in under 10 minutes at 3 amps.. 30 minutes at 1 amp..
The battery will only absorb what amperage it needs to charge fully provided, the voltage does not exceed 14.5 volt.. If you put 20 volts into any 12 volt battery at just about any amperage you will shorten the life of the battery to next to nothing.. Trust me, I have done enough solar setups to know exactly hat goes on inside a lead acid battery and all thier tolerances.. best thing for a lead acid battery is a trickle charge at .25 amps over night.

A good example is a 50% discharged standard battery from a riding mower attached to a 10 amp regulated charger at 13.8 volts will only accept 2.5 amps to recharge.. so 3 is more then it needs...

Click to expand...

You guys can argue your point with the Briggs factory service techs which is were I got the 5 hour recharge time for the single wire half wave rectifier non regulated charging system. This charging system and how it is not adequate for most homeowner operating periods has been discussed in more than one of my annual service update schools over the past 23 years.

Thanks y'all. Could I get a regular voltage regulator instead of the single diode?

@rkf_bomb You are trying to take a simple charging system that has been in use over 60+ years and make it complicated. Connect the wire with the diode directly to the + side of the battery and stop worrying about it.

I wouldn't exactly say I'm 'worried' about it. Just wondering if I could make it better. You yourself stated that it will run the battery down as the mower is not running long enough to charge the battery. I'm all for learning new things and trying to make things easier (and cheaper)for myself. I'm assuming I probably can't do it cheap though as the wires put out two different voltages.

You can fit a later model stator & voltage regulator with full wave rectifing.
You can not fit one to the existing stator easily

Thanks for your help everyone. I have one more question. I had to buy a new ignition switch as original was only a 2 position, 2 terminal switch. I bought a universal 3 position, 5 terminal switch at the local box store. It looks like briggs went from a 5 terminal to a 6 terminal switch at some point. As far as I can tell all the 6th terminal is for is the charging system wire only. Instead of connecting the alternator to the battery side on the starter relay they now run the wire to the switch. Is there a reason or advantage for this? I plan to just run the charging wire to the battery cable connected to the starter relay. I could get the briggs 6 terminal switch but it's twice the cost of the universal one I bought.

Most of the time the charge wire to the key switch is due to the product having a charge gauge or battery light. Nothing about the Briggs but Kohler recommends removing the wire to the key switch and connecting to the battery side of solenoid because of charging issues.

Alright then looks like I'm good to go. Thanks again for your help!

Ron

Hi rkf-bomb. I have an old, old snapper that came with pull start. We put an electric start Briggs on it 30 years ago. I use a regular lawn battery on it, and just put the clips on it, using the cheap Harbor Freight float charger on the battery when I am done for the day. It keeps the battery around 13v, and it is ready to go next week. Since the motor has it's own mag, and furnishes electric current for the spark plug, the battery has no drain while mowing. Since the Briggs starts easy, it would start for a month or so, even without charging. Good luck. This works for me.

Yeah I thought about that. I needed a good project though! I'll have under $100 in it and it gives me something to do. I like tinkering around in the garage. It's where I find my peace!

Hey all just wanted to say thanks again for all your help! Mower is running great! Started up first time! I still have to connect the stator charging wire to battery side of solenoid. I have all the wiring there, and the diode is crimped on and all set. I ran out of ring terminals so I just need to pick one up.

Anyway I know a lot of people get help on these forums and then disappear without letting everyone know how things turned out. Well everything turned out great, so THANK YOU!

On a side note I have extra diodes left over if anyone needs one, lol. They were $.16 each so I bought ten. Cost $8 to have them shipped. I couldn't find an electronics store around me that carried them. I don't want any money. I'll probably hold on to a few and get rid of the rest. Let me know!

ILENGINE is correct. That tiny 3 amp charge feed is insufficient. Battery also has internal resistance. It will slowly discharge over time. 3 amps will hardly run the front two lights on a garden tractor.

slomo

It doesn't run any lights. For charging battery only. I guess I'll see over time how well it works or doesn't work!

rkf_bomb said:

It doesn't run any lights. For charging battery only. I guess I'll see over time how well it works or doesn't work!

Click to expand...

I suspect with normal starting and not long start times the battery should keep sufficient charge to start the engine for the entire mowing season, and may even be fine for part of next year without having to put it on the charger. it is kind of like starting the mower and then that little charging system recharges to 99%, next run it recharges to 98% and so on until it runs the battery down to the point it won't start the engine. Which may be the reason for short life expectancies on some mower batteries.

And to add to what the others have said.
The pulsed DC uncliped so your battery gets everything from .001V up to 13 volts then down to nothing miss 1/2 a cycle then repeat is just about the most destructive way to recharge a battery.
Then there is just how much energy is consumed during start up.
Badly adjusted valve lashes will cause the starter to draw a lot more energy that correctly gapped ones .
Then add a dirty carb that takes a minute or more of cranking before the engine fires and you are looking at a new battery every season.

Hmmm. Maybe I'll just leave the charging system disconnected. The motor starts instantly so can't be much of a draw. Probably measure the time it takes to start in milliseconds! Thinking I'll just keep the battery tender next to mower and plug it in every week or so. It is so nice having electric start!