Bad battery or normal, volts drop under 12v when vexilar is on

[musky8it]

I've never read the volts on my bat when running the Vex until today so no idea how much drain there is. Last weekend got out for first time this year and my battery lasted only a couple hours(was charged), years prior it last all day.
So I charged it up, unhooked the charger and this mourning it read still 12.62v so it held the charge overnight. I flipped the Vex on and the battery status indicator dropped to 1/4 charge from full. I used my multimeter and it read 11.81 volts while running. While holding the multimeter probes on the battery I turned it off and it read 12.55, turned it back on and it dropped to 11.81v.

So is this normal for a battery volts to drop below 12v when the vex is on? Also during the summer I do charge the bat 3-4 times it doesn't set all summer.

[Fry Flier]

Actually the vex may start running but it could also glitch.

&t=192s

[DR.SPECKLER]

sounds like a dead cell.not handling voltage under load.under  12 volts the battery is basically dead.my vexilar with my sla battery starts at 12.9 and drops to 12.6 or so and stays that same voltage all day running it.

[Kevin23]

Bad battery.

[IceholeFisherman]

I'll say it again... And again... And again...
Charge your batteries, and keep in the refrigerator when not in use. It really works.

[musky8it]

Flier tks for the video post but I had already watched it yesterday and nothing in it about drain on a battery while running a Vex. All he mainly talks about is Vex problems are mostly solved by charging the bat. I have no Vex problems, bought it in 2004 and works great for being 13+ yrs old.

Everyone else I think is right, bad battery even if it held a charge overnight. I tested the 12v battery I use in my U.Cam and it did not drop very much so its time for a new bat.

[DR.SPECKLER]

Flier tks for the video post but I watched that it yesterday and nothing in it about drain on a battery while running a Vex. All he mainly talks about is Vex problems are mostly solved by charging the bat. I have no Vex problems, bought it in 2004 and works great for being 13+ yrs old.

Everyone else I think is right, bad battery even if it held a charge overnight. I tested the 12v battery I use in my U.Cam and it did not drop very much so its time for a new bat.

yup a battery with a dead cell will charge to and hold 12 volts until load is added then it takes a dump.

[Unclegillhunter]

Actually the vex may start running but it could also glitch.

&t=192s

won't comment on the problem as the folks who did have it right. I will tell you that i reached out to kill that little bug before I realized what it was!
Keep it safe! JDL

[musky8it]

yup a battery with a dead cell will charge to and hold 12 volts until load is added then it takes a dump.

did you mean to say just 12v, 12v is essentially a dead battery. Mine held 12.62 overnight which is a full charge, I wouldn't think a bad battery would hold full charge overnight but it did. Here's a good charge chart I found with info.

Gona order a new battery 12V 9Ah SLA Battery Replaces Vexilar FLX-28 Pro Pack II Flasher

but I'm in doubt I'll get to use it this season cause Indiana just got hit with some warm rainy weather, Grrrrrrrrr.

[DR.SPECKLER]

did you mean to say just 12v, 12v is essentially a dead battery. Mine held 12.62 overnight which is a full charge, I wouldn't think a bad battery would hold full charge overnight but it did. Here's a good charge chart I found with info.

Gona order a new battery 12V 9Ah SLA Battery Replaces Vexilar FLX-28 Pro Pack II Flasher  but I'm in doubt I'll get to use it this season cause Indiana just got hit with some warm rainy weather, Grrrrrrrrr.

(Image removed from quote.)

basically what I was saying is a battery with a dead cell will charge up and read 100% and the charger light will be green but will not be able to take any load without failing.i should've type over 12 v.

[musky8it]

basically what I was saying is a battery with a dead cell will charge up and read 100% and the charger light will be green but will not be able to take any load without failing.i should've type over 12 v.

Just seemed odd to me that my bat did charge a full charge of 12.62 and overnight my multimeter still read it full at 12.62v. that is what I was getting at. Most bad bats I have had may charge to full charge but then after setting the volts drop down below 12v, this one didn't.

[shaftthrower]

Maybe brushes in vex ?

[3300]

could be too much pull from the head unit, but if the battery is old or been dropped it maybe time to replace. they are 20$ on amazon. best it you try a fresher battery and test again.

some send in the head unit for a tune-up and costs 45$. they clean behind the display screen while they are in it so the display will be brighter. could be worn brushes, bushings and/or motor contacts.

[Kevin23]

Just seemed odd to me that my bat did charge a full charge of 12.62 and overnight my multimeter still read it full at 12.62v. that is what I was getting at. Most bad bats I have had may charge to full charge but then after setting the volts drop down below 12v, this one didn't.

That's just what the last couple of my bad ones did. I use them for a lot of things in the offseason, including running bait tanks for keeping shad alive when catfishing. They charge to full and then the second you turn something on you can watch the voltage act like a timer, counting down until it hits 10.5 and then shutting off. It does about 0.05v per second.

[esox_xtm]

This depends. How and where are you measuring the voltage? On my boat the same battery will read 11.8 or 12.7 depending on what device you look at. It may be the quality of the connection where a marginal connector or corrosion affects the measurement of available voltage. There may be more in play here than just "bad battery".

Make sure your connections are clean. Test your measuring device against a known source to validate other readings. Use a second device to validate your first reading before making a decision (second opinion).

[Kevin23]

This depends. How and where are you measuring the voltage? On my boat the same battery will read 11.8 or 12.7 depending on what device you look at. It may be the quality of the connection where a marginal connector or corrosion affects the measurement of available voltage. There may be more in play here than just "bad battery".

Make sure your connections are clean. Test your measuring device against a known source to validate other readings. Use a second device to validate your first reading before making a decision (second opinion).

Sounds like you have some wiring issues in your boat. Probably a bad connection or too thin of wire somewhere. All electronics should read within 0.12v of each other (they have a 10% margin of error). I have seen what you are talking about, and it's almost always a console fish finder reading less because it is rigged to the console bus instead of direct wiring to the battery.

[esox_xtm]

Sounds like you have some wiring issues in your boat. Probably a bad connection or too thin of wire somewhere. All electronics should read within 0.12v of each other (they have a 10% margin of error). I have seen what you are talking about, and it's almost always a console fish finder reading less because it is rigged to the console bus instead of direct wiring to the battery.

Agreed. In this case its a bow mount unit wired into a panel up there. I believe some it it goes thru the panel @ the console. Because I understand where its coming from (sort of) it doesn't bother me much. Now I think of it there are times when I don't see what shows up on the console unit. Could be due to low voltage. Just added to the spring "to do" list...

[musky8it]

Its a portable Vexilar, somehow we've got off topic and started about a boat unit.

The Vexilar is not the problem its a battery problem thread. I believe I said I tested another battery and the volt drain dropped very little. So like many have said, I think its a bad battery ordered a new one today so problem solved.

Tks for the input everyone, its appreciated.

[esox_xtm]

Sorry I dragged it off a bit but it's really all the same. Locator is locator, battery is battery and wiring is, well.

A little different venue but there are certainly correlations. My point was to be sure and check all connector for integrity. Even a small amount of corrosion can have a big impact. I should have just said that...