Battery

Dave R · 04-29-2021, 11:49 AM

Quote:

Originally Posted by MotorHead

I was not aware of the fact that you have to go fast for your battery to recharge. We usually leisurely stroll between sandbars and food places.

As for solar charger, great idea unless the boat is stored indoors, which we do.

You may not need to go fast, but most alternators do not put out anywhere near their full output at low engine RPM.

My advice is to check your battery voltage with an accurate meter before you turn the battery switch on the next time the boat has been used for a day (thus the battery should be charged), then sat at least overnight with the switch shut off (no load on battery). If it's fully charged, you should see 12.6V; 12.4V means 75% charged, 12.2V would mean 50% charged and anything in the 11s is really bad. You should always aim to store the boat starting with 100% state of charge.

MotorHead · 04-29-2021, 01:00 PM

Quote:

Originally Posted by Dave R

You may not need to go fast, but most alternators do not put out anywhere near their full output at low engine RPM.

My advice is to check your battery voltage with an accurate meter before you turn the battery switch on the next time the boat has been used for a day (thus the battery should be charged), then sat at least overnight with the switch shut off (no load on battery). If it's fully charged, you should see 12.6V; 12.4V means 75% charged, 12.2V would mean 50% charged and anything in the 11s is really bad. You should always aim to store the boat starting with 100% state of charge.

Can I do that in my basement ?
Currently my battery is in the basement, it is too cold to go out to a sandbar.

Let the battery sit in the basement for a week.
Charge it with a trickle charger until the charger light turns green.
Unplug the charger, let it sit overnight then measure

Would that work?

Dave R · 04-29-2021, 04:03 PM

Quote:

Originally Posted by MotorHead

Can I do that in my basement ?
Currently my battery is in the basement, it is too cold to go out to a sandbar.

Let the battery sit in the basement for a week.
Charge it with a trickle charger until the charger light turns green.
Unplug the charger, let it sit overnight then measure

Would that work?

The goal I had in mind was to test your boat's charging system, not the battery. Charge the battery fully and then bring it to a store that sells batteries, they will load test it for you and determine if it is good or not. Once you have a known good battery in your boat, try my test after a day of boating and see if the battery is fully charged. If it is great, if not, you should address it to avoid being stranded on the lake someday...

MotorHead · 04-29-2021, 04:18 PM

Quote:

Originally Posted by Dave R

The goal I had in mind was to test your boat's charging system, not the battery. Charge the battery fully and then bring it to a store that sells batteries, they will load test it for you and determine if it is good or not. Once you have a known good battery in your boat, try my test after a day of boating and see if the battery is fully charged. If it is great, if not, you should address it to avoid being stranded on the lake someday...

SAB1 · 04-30-2021, 05:00 AM

I’ve had good luck with NAPA batteries. In offseason I charge them two or three times. I do not haul them into the house for the winter.

The Following 2 Users Say Thank You to Dave R For This Useful Post:
MotorHead (04-29-2021), XCR-700 (04-30-2021)

The Following User Says Thank You to MotorHead For This Useful Post:
trfour (05-01-2021)

04-30-2021, 05:00 AM	#5
SAB1 Senior Member Join Date: Feb 2012 Location: Tuftonboro Posts: 1,230 Thanks: 190 Thanked 320 Times in 235 Posts	I’ve had good luck with NAPA batteries. In offseason I charge them two or three times. I do not haul them into the house for the winter.