DP390A Battery

Important - Please read before ordering / using your DP390A battery

Compaq laptop batteries may look VERY similar on the outside, but the quality of what's on the inside will determine how well your DP390A battery holds it's charge and how long your DP390A battery is serviceable for. Beware replacement DP390A batteries that seem unusually cheap - they may contain cheap cells, not hold a charge well, have a low cycle life (i.e. the number of times that they can be re-charged), leak electrolyte or even catch fire!

All our batteries are CE certified. Most of our batteries contain Panasonic or LG cells, - these manufacturers are constantly improving them as newer technology becomes available. Our units often outperform the original battery, in terms of capacity (4400 mAh) and cycle life.

Our DP390A batteries are available at a greatly reduced price compared to the original. if you are in any way dissatisfied, you may return your battery within 7 days for a FULL refund - batteries are "chipped" to confirm authenticity.


How to charge/condition your new DP390A battery

It is VERY IMPORTANT that you "condition" your new battery before you use it - you must understand that ALL new batteries behave erratically until they have been conditioned properly. Many people think there is a fault when they actually have a perfectly good battery which simply requires proper conditioning.

You will receive your Compaq DP390A Laptop Battery fully discharged and unconditioned. If you turn on your Compaq laptop, expecting it to work straight away you will be dissapointed. Your battery will normally take 3 or 4 charges to reach it's proper capacity and operation (sometimes more charges are needed) - until this time it is usual for it to perform strangely and hold only a little charge. Also, the LEDs and charge indicators on your charger and laptop will not give accurate information until the battery is fully conditioned - so dont take too much notice of what they do or dont indicate - just follow the instructions below.

On the first charge, your Compaq laptop may indicate that charging is complete after a short period of around 15 mins. This is to be expected - simply remove the battery from your DP390A laptop and repeat the charging procedure. You should then use your laptop - WITHOUT the assistance of mains power, until the battery completely runs down.

Repeat the above procedure around 4 times in total over the course of the next few days - make sure you allow you battery sufficient time to get a full charge, normally an overnight charge will suffice.

When the battery is fully conditioned, the battery charge indiciators and LEDs on your laptop and charger will work reliably. Also - as the battery will be taking on much more charge, the total charge time will be longer.


Occasional Maintenance

Simply run your DP390A until the battery is FULLY discharged and then fully charge again. After extended periods of non-use, you should do the same. Lots of little charges followed by partial dischrage will decrease the life, performance and capacity of your battery - but in reality, this is how laptops are usually used and this may be unavoidable.


Battery "Memory" Effect

Ni-MH batteries have more of a "battery memory" than Li-ion type batteries. Battery memory effect occurs when the battery is fooled into thinking it is fully charged, when in fact it has only reached a partial charge and capacity - even though it will indicate that it is 100% charged . This is caused by only partially charging a battery over time, or only partially discharging it. This will prevent them from holding as much charge as they possibly can (i.e. the full 4400 mAh capacity) - until you recondition them again, following the instruction above for "occasional maintenance". With Ni-MH batteries, it's a good idea to repeat the process 2-3 times.