New battery - effect on OPE engine performance?

[mrsilv04]

Is it possible for a small OPE engine to actually run better on a new battery?

On our 1995 John Deere 425 AWS (22 hp Kawasaki V-Twin, liquid cooled), I have known for some time (since last winter), that the battery was marginal. It was a Walmart labelled Exide, with a sticker indicating it was manufactured in 2006. It was to the point where if the tractor wasn't used at least every 4-5 days or so, it wouldn't start.

Well, it finally died for good last weekend, a couple hours on the battery charger did nothing. I can't complain, as 7 years on any battery is a good run.

I replaced it with a Farm and Fleet labelled East Penn/Deka battery (group U1, 425CA, 350CCA). Of course, it cranks and starts much quicker now.

And... I could swear that the engine runs better.

Could a dying battery, one that I'm sure had a much lower than normal voltage output, affect what I would assume would be the ignition and spark, to the point where it would affect the performance of the engine? Or does a battery have that much affect on an engine once it is already running?

 

[eljefino]

I doubt it. I figure the magneto makes sparks with one coil and a pulse that charges the battery with the other.

OTOH if you have a generator/ alternator setup like a car I guess all bets are off.

 

[JHZR2]

Of course it could. A battery with a shorted cell that dumps current might be putting added load on the generator/magneto/whatever, and cause funny electrical behavior.

 

[dwcopple]

Originally Posted By: eljefino
I doubt it.
+1
Once OPE is started with the battery, you can remove it all together. No effect on running whatsoever. NOTE: removing only applies to machine with hydraulic or belt driven accessories without electric lift or other odds and ends. My older stuff, all the battery does is spin the starter. Belts do the rest once the thing is spinning.

 

[mrsilv04]

Well, Dad used it tonight. He had no idea that I had changed out the battery, and he noticed that it was running better as well.

He asked me if I had "tuned it up".

 

[TFB1]

Originally Posted By: JHZR2
Of course it could. A battery with a shorted cell that dumps current might be putting added load on the generator/magneto/whatever, and cause funny electrical behavior.


I totally agree...

The load of a alternator when charging at a higher than normal rate can defiantly be felt with a small engine...

 

[Warstud]

Originally Posted By: mrsilv04
Is it possible for a small OPE engine to actually run better on a new battery?


DIY Test >>> Start it...then disconnect the battery. Report back.

 

[SHOZ]

Originally Posted By: Warstud
Originally Posted By: mrsilv04
Is it possible for a small OPE engine to actually run better on a new battery?


DIY Test >>> Start it...then disconnect the battery. Report back.


It will run but you remove any battery charging load from it then.

 

[TFB1]

Originally Posted By: SHOZ
Originally Posted By: Warstud
Originally Posted By: mrsilv04
Is it possible for a small OPE engine to actually run better on a new battery?


DIY Test >>> Start it...then disconnect the battery. Report back.


It will run but you remove any battery charging load from it then.


Plus there's always the possibility of damaging the charging or other electronic systems by doing so...

Just accept the fact it runs better and let it go...

 

[meep]

every electric start OPE i've worked on uses a separate 3 phase coil beneath the flywheel for charging. The magneto remains standalone. the magneto does not give power to, or receive power from, the charging circuit.

The charging circuit (3 phase alternator) is regulated by a crude rectifier assembly that just adds resistance to lower the voltage... it's not like a car.

Most of these things can put out something like 6-9 amps for one cylinder engines, maybe 15 for a twin. 15amps at 12volts is something like 180 watts, which is just over 0.2hp.... but if you assume some losses, like 0.3hp under full demand. in OPE this would also require full rpm to achieve.

I don't see it making much of a difference. ??