I left my tablet charging for 4 hours and it still has not charged from the micro USB port?

Memory can be a problem and some ways to fix that is by either clearing space in the storage by going to the setting of the tablet and go to the storage section. The other option is to add a micro-SD card in the tablet or add a larger micro-SD card to have more space. After that go into settings and under storage set the SD card as the default write disk and then your pictures should save automatically to the micro-SD card.Polaroid S10 Troubleshooting