I guess this means my kicker has a magneto?

[Stickinthemud57]

I'm not sure why I never noticed this, but the voltage readout on my inverter was showing 16 volts as I was motoring in yesterday, but dropped to the normal 12.7 or so when I throttled down. I throttled back up and the voltage went up. I can think of no other explanation for this than that my kicker - a 8 HP Tohatsu 2-stroke - is equipped with a magneto. Right?

[Russ]

Alternator.

https://tohatsudirect.com/product/alternator-kit/

[Stickinthemud57]

Ah, thanks!

[Be Free]

The alternator goes through a rectifier to change the AC to DC. What you may not have on a small outboard is a voltage regulator.

[Stickinthemud57]

The alternator goes through a rectifier to change the AC to DC. What you may not have on a small outboard is a voltage regulator.

I would say probably not. At one point the inverter was reading 16 volts. It's unusual for me to use the kicker for more than 20 minutes at the most. Might running it at or near full throttle for longer than that damage the battery?

[Be Free]

16V is a little high for a 12V FLA battery. 14.5V is the normal bulk charge voltage. If you have an AGM battery it would be a little higher. Before you get too concerned make sure that you are using an accurate meter. The built-in display on an inverter may not be particularly accurate.

The most likely problem you will see with high voltage is "boiling" the electrolyte. Keep a close eye on the fluid levels in the battery.

[Stickinthemud57]

Thanks, I will look into that. Meanwhile, do you think that 10 minutes of elevated voltage is likely to do any damage? I can always turn my battery switch off if I plan to go at high throttle for an extended period.

[OverEasy]

Hi StickInTheMud57!

Question A: Are you sure you have a magneto ignition system on your kicker?
—- > Some non antiquated engines actually require a battery for the ignition to work properly and some don’t.
Running your kicker without a battery may be possible but if it has a electronic ignition or computer brain box it might not like that.
I’d suggest getting the manual out and making a call to the manufacturer’s technical help desk.
—— > if there are no electronics, no computer, there are points and condenser then you do have an old fashioned magneto ignition system.
Amended : Be Free is correct below!!! Check with your owners manual and OEM BEFORE attempting to run without a battery!!!

Question B: What is your no load battery voltage when not running the kicker?

Question C: Have you checked the electrolyte levels for each of the battery cells?
—- > If your battery isn’t boiling off electrolyte as evidenced by lowered electrolyte levels then you haven’t a problem to worry about

Best Regards,
Over Easy

[Be Free]

Thanks, I will look into that. Meanwhile, do you think that 10 minutes of elevated voltage is likely to do any damage? I can always turn my battery switch off if I plan to go at high throttle for an extended period.

Ten minutes is not likely to cause damage. Keep an eye on the electrolyte level in any case. Charging with low electrolyte will damage the battery.

Do not run your engine without the battery connected! You will almost certainly blow the diodes. This is an expensive mistake!

[Stickinthemud57]

Thanks, I will look into that. Meanwhile, do you think that 10 minutes of elevated voltage is likely to do any damage? I can always turn my battery switch off if I plan to go at high throttle for an extended period.

Ten minutes is not likely to cause damage. Keep an eye on the electrolyte level in any case. Charging with low electrolyte will damage the battery.

Do not run your engine without the battery connected! You will almost certainly blow the diodes. This is an expensive mistake!

Wow, good to know. Thanks!