Ever needed to replace a dying laptop battery? If you do, you'll quickly notice that a large number of the providers offering batteries at below manufacturer cost are based in China, not noted for its standards of consumer protection.

We have had reports of poor quality products turning up from this region so don't assume it won't happen. Here is a guide to avoid being ripped off...

1. When ordering, don't assume a .com or .co.uk website address offers one iota of reliability - country-based web domains are regularly used to give the prospective customer the illusion of locality. Most of these companies are based in Hong Kong or Guangdong, feeding supply from a large number of local clone battery makers.

2. Check the domain owner on whois. If it appears to be outside your own country (which it almost certainly will if you are buying from the UK), you should proceed on the basis that you have no consumer protection.

3. Check out the contact email address and payment method. If it is a hotmail, Google mail or Yahoo mail address (i.e not a mail address tied to a domain), take that as a small minus. A serious business will invest in making itself easy to contact.

4. Periods of guarantee vary. Thirty day warranties are often buried in small print, a next to useless period of time given that even poorly manufactured batteries will tend to take between one and two months to show problems in holding charge. Six months should be taken as a minimum guarantee period, a year better still.

One company a reader reported having a problem with is powertoolbattery.co.uk. Product turned up, worked for 6 weeks and then died totally. Repeated emails to the company got no response, and the guarantee period is listed as being a hopeless 30 days.

This might have been a one off problem, but the lack of reply to emails, use of a .co.uk domain when the company is based in China, and measly 30 day warranty don't inspire confidence.

My advice is not to buy cheap (a relative term) batteries unless the supplier is a company based in your country of origin. Pay more and get a product that comes with a decent guarantee, preferably not a clone cell from a workshop. Ideally, get one from the company that sold you the laptop. They will cost you more in the short run, but will extend the use of a laptop without throwing money down the power drain.