panzertank

i have a Airtronics D8000 8 channel radio. the first time i charged it it had a long 1-2 hour battery life. when that ran out i charged it again and it had about 3/4 that time. however the next time i charged it and used it it had about 20 minutes total battery life before it started beeping saying "power low". any help will be GREATLY apreciated. P.S. i let the battery charge for like 20 hours or more. the manual says let the batteries charge for 14 hours or more so i figure this was not a problem. is it?

DMcQuinn

My Feedback: (13)

It is no problem charging for 20 hours, assuming you are using the right "slow" charger. Probably this is a 50mA "wall wart" charger. There are at least three things that could have gone wrong:
1) most likely the battery pack is not good. How old is it? Could it have been in storage for a few years before you used it?
2) The charger may be defective and not charging the pack up to full capacity. this is very unlikely
3) The low battery warning on the transmitter could be defective - beeping when really the voltage is OK. This is also very unlikely.

You best bet now is to find a friend that can put your battery pack on a measured discharger (cycler) and test its capacity. This is easy to do if you have the equipment.

panzertank

the battery is only about a month old. i charged it once and used it for a while and then didn't use it for about 30 days.
form here on it seemed to lose power

DMcQuinn

My Feedback: (13)

OK. It is rare for a new battery pack to fail like this, unless you charged it with a "fast" charger for too long. The charger that comes with the system (usually 50mA) cannot damage the battery pack even if left on for long periods of time (weeks). See what the charge rate is on the charger. If it is a wall wart type, the output current (charge rate) is printed on the part that plugs intop the wall.

rcairflr

My Feedback: (44)

Here's my advise, buy yourself a good Peak Detect Battery Charger with a discharge function, as well as a charger that can be used to properly Form your batteries. That way you can properly charge and maintain your batteries. By using the discharge function you can see for yourself what the condition of your batteries are.

It seems like a lot of people have money to replace a crashed airplane because of bad batteries, but don't buy the corrrect battery maintaining equipment to make sure that you don't crash an airplane because of a bad battery.

One of the biggest enemies of batteries is heat developed while overcharging. My guess is that while your battery was charging on the wallwart that you never checked your battery to see if it got hot. If it did get hot you possibly damaged your battery. No one can tell you if your battery is good or bad without you sending it to them and having them check it the way I pointed out above. So buy yourself a good Charger/Discharger, you will be happy you did. $.02