So I got a new battery, charged it and it showed 14.4V
Plugged it in the bike and over 24 hrs went down to 13.9V
Is that normal?
 
So I got a new battery, charged it and it showed 14.4V
Plugged it in the bike and over 24 hrs went down to 13.9V
Is that normal?
Normal resting volts on a new quality properly charged battery is 12.9 to 13.1 volts. Your charging was on a old school charger? I recommend a proper maintainer that controls the charging not just dumps 13 to 14 volts at it.
What you see is a over topped off battery that is not a big deal but not ideal. The battery will see these volt levels during normal operation. No real harm done. But if you just used the headlights for a few minutes you would see that number come back down and stay at 12.9 to 13.1 volts.
Voltage is a direct relationship to how much capacity the cells are at in a healthy new battery. 12.0 is dead, 12.5 is half, 13.0 is full 100% but the battery can't be over charged and change the "capacity of power it can hold". The over charge here is just a tiny bit extra that will be used up quick when the battery is used.
I'm not sure what charger you are using but I strongly recommend you go pick up a noco genius charger maintainer.
If you have say a 13.0 volt battery at say 80*f, it can become 12.95v at say 50*f and have the same "charge capacity" all other things being the same.
 
So I got a new battery, charged it and it showed 14.4V
Plugged it in the bike and over 24 hrs went down to 13.9V
Is that normal?
It seems right to me but I would keep monitoring it to see what happens. Fully charged is 12.6 to 12.8 according to what I've researched. Voltage after charging is higher than resting voltage and sometimes just the surface charge. My battery tester says to turn the headlights on for ten seconds before testing.
 
Normal resting volts on a new quality properly charged battery is 12.9 to 13.1 volts. Your charging was on a old school charger? I recommend a proper maintainer that controls the charging not just dumps 13 to 14 volts at it.
What you see is a over topped off battery that is not a big deal but not ideal. The battery will see these volt levels during normal operation. No real harm done. But if you just used the headlights for a few minutes you would see that number come back down and stay at 12.9 to 13.1 volts.
Voltage is a direct relationship to how much capacity the cells are at in a healthy new battery. 12.0 is dead, 12.5 is half, 13.0 is full 100% but the battery can't be over charged and change the "capacity of power it can hold". The over charge here is just a tiny bit extra that will be used up quick when the battery is used.
I'm not sure what charger you are using but I strongly recommend you go pick up a noco genius charger maintainer.
If you have say a 13.0 volt battery at say 80*f, it can become 12.95v at say 50*f and have the same "charge capacity" all other things being the same.
Have a charger similar to this one
 

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It seems right to me but I would keep monitoring it to see what happens. Fully charged is 12.6 to 12.8 according to what I've researched. Voltage after charging is higher than resting voltage and sometimes just the surface charge. My battery tester says to turn the headlights on for ten seconds before testing.
dude, you need to stop telling people wrong information. i would hardly say that 75% to 80% is fully charged. Nothing wrong with posting here but do not keep spreading bad information you found on the 1st hit you find on wiki or reddit.
 
Have a charger similar to this one
the #1 reason i go with TRIED and TRUE / Quality brands like Noco vs some amazon or eBay special or the brand "battery tender" is that when these POS devices fail, they send too much unregulated voltage to the battery and KILL THEM. quality stuff like noco fail in a OPEN circuit. I bet you 10 bucks that the charger you have has failed. i would not be using it. It may send out voltage to charge, but the regulator to STOP the charging seems to not be working right.
I have over 30 various automotive / marine batteries currently and in my life time have had/ worked on hundreds. being a avid fisherman with a many trolling motor setups has by far been the main cause of so many of them under my belt as an amateur wrencher.
Pay up for some quality, i have had 20ish various brand chargers all of them been in CONSTANT use over the last 20 years, the ONLY ones that i have are the old analog style or the noco's. I have had 6 off brand rebranded all fail and every single one of the "battery tender" brand have failed save for one OLD SCHOOL one. 11 years strong on constantly charging deep cycle marine batteries on the noco's and never had a problem.
and before all you nay Sayers start ripping on noco, they are the OG, started in 1914 and been making QUALITY chargers longer than anyone else that i know of
 
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dude, you need to stop telling people wrong information. i would hardly say that 75% to 80% is fully charged. Nothing wrong with posting here but do not keep spreading bad information you found on the 1st hit you find on wiki or reddit.
Always verify battery state of-charge before charging, and 30 minutes after charging. When a battery charger has been disconnected from the battery for one to two hours, a fully charged Conventional battery should read 12.6 volts (12.8 volts with Sulphate Stop) or higher. AGM batteries may have slightly higher voltage readings after a full charge.
Dude, this is from the Yuasa battery website
 
Always verify battery state of-charge before charging, and 30 minutes after charging. When a battery charger has been disconnected from the battery for one to two hours, a fully charged Conventional battery should read 12.6 volts (12.8 volts with Sulphate Stop) or higher. AGM batteries may have slightly higher voltage readings after a full charge.
Dude, this is from the Yuasa battery website
Our rockets call for an AGM battery. Not a flooded. AGMs have a higher resting state.
Perhaps this is where some confusion is?
Deep cycle batteries are even higher at rest.
It seems you are referring to flooded batteries. Yes you are a bit closer to correct than I am. But that's not what our rockets need.
Here is one hint at why
Directly from tunecu
It turns out that it comes to these interruptions, when the battery voltage falls below 12,5 volts,
even when connected battery charger.
Apparently, the power delivered to the modern battery chargers not prevent that.
It works perfectly when a second 12-volt car battery is connected.


Here is a good read that can shed some light on this for you
The Ultimate Guide to Battery Voltage Charts

If you are running a flooded battery in your rocket, it's going to have issues.
 
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