Battery issues I recently discovered my phone was not charging correctly, the screen ws reading "unable to charge". I then cleaned it gently with cotton swabs. I replaced the battery "invalid battery" message appears after I cleaned my phone. I removed the battery and now it reads "unable to charge" again.

try this

SAMSUNG GALAXY S5 - NO POWER, BATTERY, CHARGING AND CHARGER ISSUES

No power, battery, charging and charger issues

This guide contains troubleshooting steps and advice to help resolve issues you may experience when attempting to charge the handset.
After performing each step, please test to see if the issue is resolved.
Symptoms:

• Battery not charging
• Battery is not lasting long
• Phone won't charge
• Charging error
• Failure to charge
• Display remains black or blank
• No power
• Boot failure
• Overheating

Troubleshooting Questions

• Are you using the correct equipment?Make sure you are using an approved Samsung wall charger and USB charging cable. Other brands of charging accessories may have different voltage parameters and could cause charging issues when used with Samsung devices.
• Have you charged your phone for longer than 30min? Leave your phone plugged in to the charger for about 30min without powering on. In some cases, it may take slightly longer for your phone to charge.
  
• Is the battery icon displayed on the screen when charging? After charging your phone for a little while you should get a battery charging icon appear on the screen which will indicate that your battery is charging properly.
  If the charging icon appears, leave your phone for a little longer before you try to switch your phone on.
  If however, the screen is blank and nothing is displayed, follow the below troubleshooting steps.
  
• Is the charging cable plugged into a USB port? Some charging cables can disconnect from the wall outlet adapter and plug directly into a USB port. However, when plugged into a USB port, the charging process is much slower due to the limited power output of USB ports. Instead, plug the device directly into a wall outlet to speed up the charging process.
  
• Is the outlet faulty? Try a different outlet or check for a switch connected to the outlet. If possible, try powering a different device on the same outlet.
  
• Does another USB cable, or wall charger work? Charging issues can occur if either the battery or charging cable is damaged. Verify that the charging contacts are clean. If necessary, clean the contacts using a cotton swab and rubbing on isopropyl alcohol.
  If possible, test the charging cable by plugging it into another device and seeing if the device charges. Alternatively, try charging the device with a different cable. This may mean changing out the cable or the adapter on two-piece chargers.
  If charging through a car charging kit, ensure that the car engine is running, and if possible try to charge other devices using other cables, through the same car kit. If none will charge, then it is likely there is a fault with the car charging kit. It is recommended to continue to cross-test devices, cables, and car kits until the problem device can be identified.
  If the device charges when using a different USB cable or wall charger, the issue most likely lies with the charging accessory. In this case, follow the approved charger repair / replacement process.
  Also, if the charger is connected via an extension or other multi-socket adapter, remove this and plug the charger directly into the wall-mounted socket. This will eliminate the possibility of a fault with the adapter.
  If you are still unable to charge your device, continue to the next step.
  
• Has the phone experienced any shock or exposure to water? Accidental physical shock to a handset can sometimes cause problems to arise with battery or charger, as these components contain delicate parts, particularly. Damage can occur either to the component itself, or to the component's connection to the motherboard.
  Water exposure can also lead to damage of these components, however due to the slow way in which this type of damage can manifest itself, the cause may not always be readily obvious.
  With any physical damage of this nature, the only recourse is to contact the device manufacturer, and follow their approved repair or replacement process.
  

^_^

In my technical experience
this occurs mainly in the samsung mobile phone

it is not because of your battery.it is because one of your ic chip is being damaged......you need replace it.you can touch the phone internal chip and see which one of the chip is getting more heated up..you need to replace it..can you please tell me your model no.?so i may help you in chip replacement.

Remove battery, clean the charging port, clean contacts between battery and phone, also be sure to use an original Motorola charger instead of one of those "universal" type chargers.

you need a new batt.

go to any local phone store to get one.

-

Try a different battery in it when you are trying to charge if it works your fixed if not it may be as you suspect.
The other way is to try a different chargers well if the prob is still there then it is in the phone and needs a tech to look at it

I plugged my phone up and all of a sudden got the message "Unable to charge" on it. I changed chargers (i had an extra one), i changed batteries (i had an extra one), and i swapped every combination imaginable.
My solution....
My Razr's plug has an opening to plug the phone that resembles a person's navel, and it got dirt and dust bunnies in it while it was in and out of my pockets. I was able to take an old tooth brush (or your new one if your really desperate), and got a can of office duster that you use to clean keyboards. Turn the can of office duster upside down for a second while you are spraying it and liquid will come out as you are spraying the connector. Immediately after that, use your toothbrush to work it inside the dirty connector to free it from anything that will keep it from making good contact. Then, hold the can of office duster upright and it will only spray air... and blow the connector free of anything that you loosened with the brush. Repeat this process if after all this it still doesn't work... because you have a REALLY REALLY dirty connector if it doesn't work after the first try.