Hi All,
Does anyone know of a device that can check the condition of the batteries on the aircraft to make sure that they are not going to fail or about to ? Where could I buy one ?
Thanks in advance,
Wayne

Tower Hobbies, or most reputable LHS sell an Expanded Scale Voltmeter (ESV). It is designed to put a slight load on your batts when it checks them. Otherwise, you only know what the static voltage is, and if your electrical gear, RX, Servo, accessories, puts a load on them, a good battery on the ground can become a bad battery during use. Also great for calculating how many flights you can get out of a battery, both TX and RX.

Im sure someone has a link for the Tower Hobbies, or Hobbico ESV.

Here's a link to one on the Great Hobbies site...

http://www.greathobbies.com/products...od_id=HOBP0356

There are also a number of devices such as the AirAlert which plug into your receiver and have a series of lights to indicate battery voltage or flash lights or start beeping if your receiver voltage drops too low...

http://www.greathobbies.com/products...od_id=HOBP0335

Even a volt meter that puts a load on the battery as it reads it won't tell you how much capacity that your battery pack has. You can buy a recycler/charger or one of the capacity testers. You charge the battery pack and then connect it to the battery tester. It will discharge the pack to 1 volt per cell and shut down. Then you move the switch and the unit will light up and tell you how many ma it took out of the pack in ma. Then you recharge the pack and your ready to go. Then you know exactly how good the pack is. ie. if a pack is rated at 1600 mah and the tester pulls out 1575 ma, then you know that the pack is in good shape. If it only pulls out 1100 ma then you might want to consider replacing the pack. A good one to look at is called Super Test. http://www.siriuselectronics.com/ind...roducts_id=120

FASTSKY is absolutly correct . in a sense ,there is no device that can tell you your batteries are about to fail.
the ESV WILL tell you the state of charge and if there is a dead cell. it will, if used correctly, tell you how well your batteries hold a charge & for how long. case in point ; a TX I had could be fully charged but in use the old weak cells became obvious when placed on th ESV after only two flights. the ESV will also catch a bad pack dierctly off the charger when you think they are ok.you need to charge /discharge packs several times & find out how long that individual pack will last. plus a safety margin under load.

Since you are in Alberta check out Greathobbies.com. They are a Canadian outfit and have better pricing than Tower when you take into accout US/Can. $ and customs. Also great service and free shipping with MAAC insurance. For in plane use you can install a Volt Watch which lights up different colors of LEDs depending on the voltage of the battery. Look for the green leds to be lit before and after each flight. If it gerts into the yellow then time to quit for the day. Cheap insurance. I tested them and found them to be very accurate.[8D]

Hi Fastsky,
Thanks for the info. What I done so far, till I can afford to buy the ESV, was to buy and install on my Hangar 9 Alpha 40 was the Micro unit Fail Safe by OFNA part # 91002. It tells me by a flashing light ( LED ) that my batteries are low, also it is set to turn my engine to idle when the radio signal is lost. On my Hangar 9 P 51 Mustang PTS I installed what you suggested an on board battery monitor. The one I got is from Venom, part # 0640 and I installed it on the servo deck so that all I have to do is to look through the canopy to check the batteries.
I have another question, what would be the best adapter that can be used to install on the Mustang to charge the on board batteries so that I don't take the wings off all the time?

Get a flashlight bulb (4 cells) and put wires on it. Connect a resistor to the wires and a connector to plug into your pack. This is a cheap way to see if your pack will handle a load.


If you use a 5-10 ohm resistor and the bulb still lights then you should be OK.

cool pool: You do not need anything fancy, or computer operatered, or whiz bang to get the info you need.

All you need is some time and an attention span.

When you get an ESV, make yourself a chart, and record the voltage levels every 15 minutes. That way you will know how long your battery is good for. This is the way we did it back in the dark ages.

A vote for Volt Watch. Already saved one plane for me! VERY simple to install and use and the new version is smaller than the original.

I know one guy that thought it wasn't very accurate when the Red light lit up after just 3 flights on one of his planes. However when he checked the battery pack at home after on an ESV it turned out the pack was very low due to a bad cell!! [8D]