HP DV4 Laptop Battery Charge and Discharge

Minimize discharge insufficient charging or excessive discharge in fact, a good solution to excessive discharge, not the end of discharge limits set too low can be, I have been a 3%.

Often with a Hewlett-Packard hp Pavilion dv4 Series Battery may just not a long time, such as notebook battery left 70%, Hewlett-Packard (HP) DV4 laptop battery is automatically charged if the switch to the power supply, then such a cycle, there is no Hewlett-Packard (HP) DV4 laptop battery life is not the number of cycles absolute dead, but always it will reduce the notebook battery capacity lithium-ion laptop battery is said to have no memory effect, but in fact only relatively low memory effect, nothing more. Unfortunately, IBM did not provide a solution to discharge less than the charge method, however provide a foundation to solve this problem. This is what I found on the R31, may not necessarily suitable for other machines, but the method should also be far off, after you've tried do not forget to share posted.

R31 charging circuit based on the status of the power to decide whether to charge the hp Pavilion dv4 Series Battery. Power supply output voltage is 16V, error of plus or minus 0.2V, if the voltage is lower than 15.5V, the charging circuit not give notebook battery charge, while books can work properly, this is the foundation of IBM offers a solution to the problem. But the foundation is really vulnerable, because if the voltage is lower than 15.2V, the books will be converted to power laptop battery, even if the power plug in the books is useless. In other words, we can toss the space is 0.3V.

If you can find a 15.5V, more current 3A switching power supply, then the problem is solved, otherwise please continue to read.

Reduce the output voltage of the power supply 0.5V is not an easy thing, the series resistance is not enough, because the voltage across the resistor will change as the current size. I use a silicon rectifier diodes required to allow current 2A above, otherwise the tube too hot. Silicon rectifier diode forward voltage drop to between 0.7 and 0.5V, just to meet the requirements. Now this type of pipe are plenty in the electronics market, the price is less than 2. Specific to the different book on the situation may be different, the best time to install hand a digital multimeter Cece. Forward tube is connected in series in the power output of the power plug and then followed by a buy notebook. The diode reverse does not matter, the book does not work it wants to, and then, in turn, can be connected to the.

Thus, the decline in the power supply output voltage of about 0.5V drop too much, the book will be converted to a laptop battery work, if the drop is too small, the book will give notebook battery charge, the specific number you tried to know in their own book.

Of course, if your Hewlett-Packard  hp Pavilion DV7 series Battery is already full, this circuit is not necessary, and you can not use it directly to the power outlet connected to the books.

So far, mentioned at the beginning of the two problems are solved. Now you test the results, the estimated results in a different book may be best to first take a circuit to try, so it took 10 money wasted Finally, I wish you good luck! Good use of your lithium laptop batteries!

Special note:

Most likely to commit errors when modify the plug is polarity engage anti-(the diode polarity to engage in anti-does not matter), so you must be carefully examined, measured with a multimeter and use different colors of the wires connected to the positive and negative. I do not know that the power the polarity to engage in anti-burn the books will have not tried!