BONAI 2600 maH cells Bonai are 3 to 4 times longer lasting than many 3000 maH lighter cells.
I've been testing other battery packs and have discovered that the weight of the battery pack is a good indication of the longevity of the battery pack. Before buying anyone's cells, ask them how much they weigh? I weighed the 2800 maH Bonai cells at 1.6 ounces, the another battery cell I've used in the past weighs only 0.7 ounces. The Bonai cells cost me more but the performance is about 4 times longer when I test them will all my HP-45 "8" digits lit up. The Bonai runs for 180 minutes when some 3000 maH cells only run for 30-45 minutes. Not all NiMH cells are formulated equal, and the branding of capacity may be exaggerated by some manufacturers.
First Time Recharging: Be careful the first time you recharge the battery pack. Charge it for 30 minutes and see if the battery pack is warm. If it is warm then only recharge it for 30 minutes in the future. Different USB cubes have different amperages so be careful.
Recharging: Your HP adapter will recharge the battery pack many times. A fully charged battery pack should last for about 1 hour +/- of continuous use. The HP adapter/charger will recharge the battery pack faster if you turn off the display, yet will also charge it with the display on. These batteries will completely recharge through your plugged in HP adapter OR my USB charging cable in about 1 hour. It should be rechargeable many times.
Battery Storage: Please protect your beautiful HP calculator! All new rechargeable battery packs will eventually leak a corrosive acid that may harm your calculator. However, as a precaution, write on the label the purchase date plus three years after installing it for the first time. Conservatively replace after three years (could last much longer). If you are not using the calculator for a long time, please consider removing the battery and place it in a sealed plastic bag. These devices are just too awesome to risk any potential damage.
Shipping: Shipping costs are listed below. For multiple battery pack purchases contact me for actual shipping costs. BTW, 93.9% of my sales are mailed in one day.
Also check my other HP calculator battery packs (Spice, Classic and TopCat) and USB charging cables for the Classic calculators. I'm working on a stand alone Classic calculator USB charger.
Hope to add you to my list of satisfied customers. Since 2001 I've sold over 6,500 HP calculator battery packs.
Sincerely, Mark Hoskins