Battery draining

Ronniewhite

Petty Officer 2nd Class
Joined
May 26, 2022
Messages
199
I have a 2000 Johnson 25hp 3cylinder. I got a used Napa battery, it's not even 2yrs old. It had to be charged when I got it , it was at 25 percent. I checked it after fishing 2 nights ago and it was at a 100percent. I just checked it now and it was almost dead. The key wasn't turned all the way off. Would that drain the battery? There's nothing on the battery that could be draining it. It's just for starting the motor.
 

mike_i

Ensign
Joined
Jun 28, 2017
Messages
942
What is the capacity of the battery? Did you buy a used battery? What kind is it? Starting or deep cycle? Get it load tested. What are you useing to test? Do you have a bilge pump? Check the battery voltage with the motor running. First get it load tested.
 

Ronniewhite

Petty Officer 2nd Class
Joined
May 26, 2022
Messages
199
It's a Napa matenice free battery. Just motor on it for starting. Yes it was used .
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,641
I have a 2000 Johnson 25hp 3cylinder. I got a used Napa battery, it's not even 2yrs old. It had to be charged when I got it , it was at 25 percent. I checked it after fishing 2 nights ago and it was at a 100percent. I just checked it now and it was almost dead. The key wasn't turned all the way off. Would that drain the battery? There's nothing on the battery that could be draining it. It's just for starting the motor.
Charge it up and take to any auto parts store and have them load test it. I'm pretty sure that the key being on can produce that situation. Pretty easy to diagnose though, charge it, and leave the key off, then test.
 

Ronniewhite

Petty Officer 2nd Class
Joined
May 26, 2022
Messages
199
Ya im doing that right now. I was just wondering if anyone new if the key being on could cause this.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,224
I don't think leaving the key on will cause that, IF it is only used for starting, as you said.
Are you fishing at night? Lights?
Easy to check for drainage with an ammeter. Many multimeters have an up to 10 Amps DC scale.
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,641
I don't think leaving the key on will cause that, IF it is only used for starting, as you said.
Are you fishing at night? Lights?
Easy to check for drainage with an ammeter. Many multimeters have an up to 10 Amps DC scale.
Again, and I think F_R could be right, but leaving the key on with certain ignition systems can cause a drain. You state that after fishing the battery was at 100% and then when you came back to it it was empty. What you didn't say is how long was that? Was that a day was that a week? Also, I was always told leaving the key on an engine is not running is also hard on the system so don't do that again which I'm sure you probably already know. F_R again is correct, you can check for a drain by doing a periodic draw test. You do use an amp gauge but it does take some knowhow. Also a lot of the YouTube videos on it are incorrect. Again, and I repeat, it's easy to take the battery somewhere to have a load test. Try and eliminate one problem at a time. Hope that helps.
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,462
Leaving the key in ‘on’ position will not draw on battery, as battery has nothing to do with spark. But if you have something connected to the “I” (ignition) post on the ignition switch, that will be energized and can draw current. Like a gps puck for gps unit. (Even if gps is switched off). That post is energized when key is on, motor running or not.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,224
Leaving the key in ‘on’ position will not draw on battery, as battery has nothing to do with spark. But if you have something connected to the “I” (ignition) post on the ignition switch, that will be energized and can draw current. Like a gps puck for gps unit. (Even if gps is switched off). That post is energized when key is on, motor running or not.
x2. Battery has nothing to do with the ignition system. But some accessory such as a tach connected to "I" might.
 

airshot

Vice Admiral
Joined
Jul 22, 2008
Messages
5,081
When you say battery is 100% ....what does that mean ? 12.6 volts and above is a full charge....below 12 volts is pretty much dead. 12.3 volts is approx 60% full..etc. Check with a volt meter to be sure. If the battery has dropped below 11.8 volts then it needs replaced as most wont recover from that low of a charge
 

Ronniewhite

Petty Officer 2nd Class
Joined
May 26, 2022
Messages
199
Again, and I think F_R could be right, but leaving the key on with certain ignition systems can cause a drain. You state that after fishing the battery was at 100% and then when you came back to it it was empty. What you didn't say is how long was that? Was that a day was that a week? Also, I was always told leaving the key on an engine is not running is also hard on the system so don't do that again which I'm sure you probably already know. F_R again is correct, you can check for a drain by doing a periodic draw test. You do use an amp gauge but it does take some knowhow. Also a lot of the YouTube videos on it are incorrect. Again, and I repeat, it's easy to take the battery somewhere to have a load test. Try and eliminate one problem at a time. Hope that helps.
It was 2 or 3 days of sitting with the key on. I charged it yesterday and went fishing last night got 3 walleye too👍. I checked it this morning it was still charged. The key is off so I will see what happens over the next couple days.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,904
Leaving the key on will drain the battery as it turns the rect/reg on thru the purple wire.
 

Ronniewhite

Petty Officer 2nd Class
Joined
May 26, 2022
Messages
199
That makes sense because I just went out and checked the battery with my charger and it's still charged
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,612
I would opt for a couple of those NAPA batteries, fully checked out. Charge them overnight with your A/C charger when the boat is in the yard. Use one for starting only.
 

Ronniewhite

Petty Officer 2nd Class
Joined
May 26, 2022
Messages
199
I would opt for a couple of those NAPA batteries, fully checked out. Charge them overnight with your A/C charger when the boat is in the yard. Use one for starting only.
That's all it's used for is starting
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,440
as per post 7 (FR)..... measure drain current with key ON only.....

in any event the solution is simple...
 
Top