If the charger has a ammeter on it then it should show close to zero which means the battery is no longer pulling any current from the charger which would mean the battery is fully charged. If it has only a voltmeter then it should show 12.5-13.5 vdc
A fully charged battery will read 12.6 volts. A battery reading 12.4 volts is 75% charged. 12.2 volts = 50% charge, 12.0 = 25% charge. You should use a battery charger to charge any battery reading less than 12.4 volts before installing it on the vehicle.
12v
Check the level of the electrolyte (water) in the battery if possible. If it is near full, then reconnect the battery charger and charge it at the 2 AMP rate. This is known as a "trickle" charge. Your charger may have the 6 amp charge rate also. The amp meter on the charger will indicate a lower and lower reading as the battery is charging and accepts the charge. An Auto Zone can "load test" your battery for free if you can get it to one of their stores. Your battery sounds weak and needs a good charge (be patient...it takes time) or needs replacing.
12.5 volts
No it will have high conductance
A fully charged battery typically exhibits low conductance readings because conductance is a measure of a battery's ability to conduct electrical current, which can be influenced by factors such as internal resistance and electrolyte condition. A fully charged battery, if in good condition, should have low internal resistance and optimal electrolyte levels, leading to higher conductance. Therefore, if a fully charged battery shows low conductance, it may indicate issues such as sulfation, aging, or electrolyte depletion, which can hinder its performance.
With a fully charged battery (12.68 volts) and engine running at idle with no accessories on, 14.5 volts. You will not get a accurate reading if the battery is not fully charged.
With the battery fully charged (12.68 Volts) and a volt meter connected to the positive and negative battery posts, run engine at idle with no accessories on, voltage reading should be aprox 14.2.
Test the battery with a digital voltmeter. You should get a reading of 12.6 V if the battery is fully charged. If the battery is fully charged then you know the alternator is functioning properly and your problem is more than likely a defective starter.
It could just need charged.It could just need charged.
Be sure the battery is fully charged before you start. A fully charged battery should read 12.68 Volts. If the battery is very low when you check the alternator output it will not give you an accurate reading.
Taking a voltage reading on a battery provides insight into its current state of charge and overall health. A fully charged battery typically shows a voltage close to its rated voltage, while a significantly lower reading may indicate it is partially discharged or defective. Additionally, comparing voltage readings over time can help identify issues such as self-discharge or capacity loss. However, voltage alone does not provide a complete picture of a battery's condition; other factors like current capacity and internal resistance should also be considered.