Rad said:
ozz93666 said:
The device in post 1 is excellent ... I use it .
When you connect the cell it gives voltage with zero current , press the button and it starts to discharge at the rate you have set by a resistor , I use a coil of single strand telephone wire , length cut to give the right resistance ...
Thanks ....What length and diameterwire are you using as your load resistor?I just tried to measure a 25cm length of 0.6mm diameter wire rescuedfrom solid cat5/6 cable.[/diy]
You'll need quiet a length of wire ... I had some two strand telephone wire used for connecting outlets around the house , fairly thin and it was magnetic !! very unusual to use copper plated iron wire for electrical work , but phone lines don't carry much current , so I guess they used iron since it wascheaper , and just what we need since it will be high resistance ... I srippedoff theouter plastic , leaving the 2 wires each with aplastic covering , I wound about 10 meters of this into a compact bundle , trimmed some off till I got the resistance I needed by trial and error.... copper wire is not very suitable it would have to be thin enamelled and quiet long , a coil ina transformer perhaps .... most people will buy standard resistors , high wattage , i just had the wire lying around so i used it .
A critical part is the connection and disconnection of the cells to the device , I've tried 3 different styles and none are very satisfactory ...
The style with curly springs on one end are no good for a firmconnection
This is the best type IMO
It gives a firm connection but a real hassle to load and unload cells , I've decided to make my own custom made thing , with two 12v solenoids that when powered, push contact on the ends of the cell...
I've even bought one of these , 7 euro .. supposedly designed for the job ...it's useless ...... Iget everything from eBay ..