Will not come on or be installed

It sounds like your alternator is not charging the battery. Fit a new battery remember to undo negative lead first to remove and fit positive lead first to refit the battery. When the new battery is filled please charge it using less than 1 Amp DO NOT use a car charger or try to jump start it. Your new battery should show 12.5 to 13 volts on a meter for a 12 volt system and 6.3 to near 7 volts for a 6 volt system. Start the scooter and check across the battery terminals your meter should show about 14.4 V for 12 volt battery and about 7.5 V for a 6 Volt one. No voltage increase means your charging circuit is not working. Either the alternator or rectifier(regulator) are not operating correctly. Worst case scenario is both units dead.

That would mean your battery is dying and you need to go buy a new battery for your laptop. You can buy new batterys for around $40
Find a store that sells laptop parts or go online look on amazon or next tag also when you get your new battery plugin your laptop charge your new battery so it has a full charge.Then when it is done charging unplug it and use the battery until it dies, then plug it in again to recharge it never leave it plugged in if it is fully charged for long periods.if you are using your laptop at home you can pull out the battery and use it when its plugged into the wall this will help to extend your battery life just make sure you have a fully charged battery before leaving your house. always unplug your your laptop when its is fully charged this will also extend your battery life for along time

Reassemble the battery once more and charge your laptop via stabilizer.

The power receptors next to the battery sound like toast. Try running the computer off of just the charger (correct one) with no battery. If this works, you need a new battery. If this doesn't work, your computer needs a new power supply. Hope this helps =]

The Battery is bad and so its not retaining charge, You may need to get a new battery and from an authorised reseller.

It sounds like the power socket on the laptop is faulty and needs replacing or resoldering. To check this, power up the latop with the power adapter, wriggle the plug in the power socket and check if the battery charge indicator flicks on and off indicating charging and not charging. If it indicator flicks on and off then you have a faulty power socket.
This can be repaired but required the laptop to be completely dismantled to access the power connector.

usually 8 hours.

for first charge.

on a brand new battery

does your battery have one of those charge indicator panels on bottom?

also, it's possible that the connection from battery to the internals is shot..if that's the case, then you're looking at a major motherboard swap

It's also quite common for the poorly designed power pin/socket to fail. the day in and day out tugging and pulling on the cable does the damage.

Here's a video that talks about the problem and a cure. . .