JerB

hey there guys

I have a rather how you say,, stupid question. I have half a dozen or so 7.2 batteries but dont know really how much juice is left in them, I havent charged them in a few months but they still run my tanks and was just wondering if there is a device that will tell me how charged they are and if they need a charging or not? would a multimeter or somehting like that tell me?

sorry for the rather confusing and odd question[&:][&:]

raimian

i usually give mine a full discharge (with a 12V bulb from a car headlight) if they havent been used for a while, then fully recharge them.

the reason for this is that nicads have a memory problem where if you recharge them all the time from half full, they will only work down till half full(they wont fully discharge)

with nimh they dont have a memory problem, but its better for the battery to fully discharge then recharge (makes the battery last longer)

i hope this helps

JerB

cheers mate, yeah that does help. How would I go about hooking up a 12v lightbulb? sounds like a cool idea[8D]

Thanks again

uly

you could get a charger with a discharge and cycle mode [&:]

JerB

would you happen to have a link my friend? Im not all that familiar with some of these chargers?

Jeremy

raimian

you should be able to pickup a tamiya connector with lead from your local model shop or online then just try it with the bulb till you workout which wire goes where (i cant say exacly how to connect it as bulbs tend to vary from make to make)

you will be able to use this setup to discharge most batteries with a tamiya connector.

Richard L.

My Feedback: (24)

Discharging with a light bulb will work. However, care must be taken to avoid overdischarging, which can result in cell reversal. It's recommended to keep around 1 volt per cell. So if you are using a 6-cell, 7.2V battery pack, you only want to discharge down to 6V. Some modern "smart" chargers come with discharge and cycling functions.

Richard L.

My Feedback: (24)

Some reading on Ni-Cad cell reversal: [link]http://www.cgi.ezonemag.com/pages/faq/a305.shtml[/link]

Also note that it's not necessary to discharge a Ni-MH battery pack.