We could find lots of knowledge about how to maintain your laptop battery, but not so much about ac adapter.
However, laptop AC adapter, like the batteries, is an essential element of your machine and is also the cause of a great number of breakdowns. Indeed, one of the elements most fragile of your laptop is the AC connector, i.e. the connector female in which comes to plug in the plug of your AC adapter.
An adapter in bad condition (stripped cable, broken case repaired with tape...) is often the cause of a fatal electric problem to the motherboard of your laptop. To avoid that you just have to purchase a new AC adapter (genuine), it is always less expensive than a repair or a swapping of the motherboard.
The repetition of these plug in and sometimes their useless violence ends regularly up tearing off the female connector of the motherboard.
That often occurs by stage, initially light poor contact, then as you move the cable in all the directions to find the current, the connector is torn off definitively, or the produced sparks roast the motherboard.
To try to save some dollars (whereas often the genuine adapters are not much more expensive) or simply because their retailer does not propose a genuine adapter, much buy "compatible" adapters.
Let me be frank, for repairers these ac adapters are a blessing! Their male connector, relatively adapted to the socket of the laptop, tears off more often than others the females connectors.
Their voltage and their amperage more or less close to the needs for your laptops and a sometimes irregular flow, even straightforwardly random, and their annoying tendency "to kill the fuses" by at the same time roasting your motherboard and other power cards, are an important source of occupation for the technicians.
The failure rate, properly incredible, due, in an unquestionable or probable way, with these adapters makes that I dis-advise them formally. I am the first to propose to use compatible parts when they are less expensive and as powerful as the original parts. But for the AC adapters I advise prudence.

Papatek.com supplies several brands of laptop ac adapters like Dell, Compaq, IBM, etc.

Acer Aspire 1410 AC Adapter(19V 3.42A)
Dell Inspiron 8200 AC Adapter(worldwide use)
Acer Aspire 1200 AC Adapter(High quality)
HP NW8440 AC Adapter(Shipped fast)
HP NX9000 AC Adapter(Best price)