Charge Voltage

[BSeward]

I had a little digital voltmeter, so I put it on my Husqvarna tractor. I'm getting almost 17 volts after the engine is running a while. I'm well connected to a switched hot wire and a good ground. Any opinions on if this is too high? I know the meter is accurate. (The picture was taken right after starting the motor, before the voltage started to rise.)

 

[Jetronic]

yeah too high, battery won't love it

 

[zfasts03]

Sounds too high. Maybe, but don't think it's okay for a tractor, cars are 13.8-14.8 volts while charging by alternator with the car running.

 

[tig1]

Maybe you volt meter is wrong. Borrow someone's VM and double check it. Should be in the 14+ range.

 

[wrcsixeight]

Check your voltmeter on your car battery, see if it is ~ 3 volts too high there too.

Lead acid batteries at 77f pretty much never want to be brought above 14.8v

The highest voltage ever recommended for flooded lead acid batteries is 16.2v, which is called an equalization charge which is an intentional overcharge, after a regular 'full charge' has been applied.

EQ charges are done on deeply cycled batteries that don't get returned to a true full charge often enough. EQ charges are very hard on a battery, and should only be performed when the cell's specific gravity are 0.015 apart from each other or when the battery capacity is obviously much lower than expected.

Bringing the lead acid battery to 15.5 to 16.2v for the EQ charge needs to be closely monitored and the specific gravity measured often. When SG stops rising, accounting for rising electrolyte temp, or reaches previously determined maximum, terminate the EQ charge. This can be 10 minutes to 10 hours depending on the battery, and th elonger it takes is a likely sign the battery is compromised and is nearing the end of life.

Most starter batteries will not take kindly to an extended duration EQ charge, and once again the EQ should never be initiated until after amperage stops tapering at 14.4 to 14.8v first. Forcing a discharged battery to 16.2v when it is still undercharged is even harder on it. You will hear the battery fizzing like a recently opened soda, 6 of them. and lots of oxygen hydrogen and a sulfuric acid mist will be escaping the caps.

 

[mk378]

It may have an unregulated charging system. If the blade clutch is not electric that is likely.

 

[Donald]

First check your voltmeter.

Its good to have a decent DVM around for a variety of reasons. I have about 5. Get the $20 to $30 one at HF. (but not the free one).

Don't expect a super sophisticated charging system on a riding mower.

 

[chemman]

Odds are you have a bad voltage regulator and the AC voltage from the "alternator" is not being converted to 100% DC. Also, batteries wont be charged from the AC voltage it's putting out. Look at the B&S engine manual for your Husky to get the part number and then order a replacement from someplace like Amazon. It's up to you but I would look at getting an aftermarket voltage regulator from Stens. Rotary, Oregon or Arrowhead and save some $$$ as the Briggs & Stratton replacement regulators are over $50.00.

 

[ragtoplvr]

Most of the lawn tractor regulators can be switched to the common and cheap on 74519-88 Harley regulator , they are under 30 dollars eBay and amazon . It has 2 wires to a plug, they are the ac. You can cut the plug off and splice the wires to your alternator The body is grounded and the lead is +14.2 DC to the battery. They are bigger and can shed much more hat so almost never fail on a lawnmower.

 

[ondarvr]

As mentioned, unregulated systems are somewhat common, they rely on something operating to drain off the excess voltage.