There are 3 key points you need to check before you start using that new charger. If any of these points mismatch, you could overheat the charger or laptop/mobile/battery or even blow the damn thing.
Refer to the image above for all of these points
1. INPUT Voltage – represented as “120 VAC” or “230V” or “220 Volts” – or any combination thereof. This MUST match with your mains voltage – if for example I try to use a 120V INPUT rated charger in India (where the mains voltage is 220V or 230V) I’m likely to blow the mains and have a very burned charger & laptop on my desk.
Often you’ll also have something like 60 Hz’ and/or a ‘6.5 W’ or ‘0.05 A’ or ‘5 mA’ – these are not very critical for our purpose today.
2. OUTPUT Voltage – represented as “6 VDC” or “6 V” (DC is assumed) or “6 Volts” (DC is assumed) – is the amount of power that’ll be pumped into the device itself. This must be a near-exact match with your earlier charger – so if I have a charger that used to supply 23 volts and a new one that is 22.5 volts – that’s probably acceptable, but the charger will heat up a bit more than usual.
The additional rating of ‘500mA’ or ‘0.5A’ here is extremely important – and must be close to the earlier rating. If I swap a 6VDC 500mA charger with a 6VDC 100mA charger – i.e. 1/5th the number of Amps – my device will charge at 1/5th the rate! Or otherwise if I double it and go for a 6VDC 1000mA charger – my battery may go kaput before I have a chance to react… So a risk either way. Though if the rating were closer, like 650mA and 500mA that could probably work without too much risk.
3. The little symbol you see above the Factory ID indicates the direction of electric current flow – this is absolutely critical, and must be exactly the same as the old charger. If in doubt, DON’T use the new charger. A change in this spec can result in the device burning immediately or could cause the battery or charger to explode.
You would not believe the number of times I’ve seen people use incompatible chargers and damage themselves or the device they were trying to charge. The best choice for a laptop or mobile charger is always an authentic distributor for the product line, and no one else.
Once you understand what degree of leeway you have for a particular device you may consider swapping chargers – so for example a Micro USB chargeable phone will likely power up pretty well if using another Micro USB charger – or via a data-cable plugged into a laptop (since it’s based on the same basic rating).