My i206b came with a temperature probe. The manual doesn't say much about it, so I have a few questions:

1. The lead on the probe is only about 12" long and the probe port is on the opposite side of the charger from the charge and balance connections - so it is basically too short. Can the probe lead be extended without adverse effects?

2. When parallel charging multiple lipos, is it a waste of time to use the temp probe on just one of them? Does anyone use multiple temperatue probes?

3. Any recomendations on the temperature cut-off setting? Typically, I don't charge over 2C and my batteries heat up very little. I generally check each of the batteries once or twice during the charge cycle with my hand to see if any are getting warm.

Thanks in advance for your help.

What type of probe? Is the two wires two different metals? if it is, it is a thermocuple and you cannot extend it without using thermocouple extenstion wire (basicall the same two metals).

if it is not, it is a thermistor and you are fine.

In both cases, makes sure both wires are the same length.

The temperature probes I've found in battery packs were 10K thermistors. If you put a Ohm meter on the leads you'll see a resistance reading and that resistance will go up and down with the temp if you hold the sensor (looks like a ceramic grain of wheat or small round capacitor) between you fingers.

A 10K thermistor will read 10,000 Ohms resistance at a temperature of 25C normally. The attached table is a temperature look up table for one brand of 10K, 3K, and 20K thermistors.

I checked the temperature probe I bought with my eLogger V3 and found it was a 10K thermistor also, so I was able to make and use my own temperature probes for that. The ones I made are smaller and can be put right inside a motor and up against the windings. In comparison tests they read with 1-3 degrees of the of Eagle Tree probes.

The thermistor had leads that were about 25mm long, I extended those with servo wire and the length of the wire (18" or so) changed the resistance a small amount but that not enough to be a concern for what I am using them for.

Jack

Originally Posted by DKNguyen

What type of probe? Is the two wires two different metals? if it is, it is a thermocuple and you cannot extend it without using thermocouple extenstion wire (basicall the same two metals).

if it is not, it is a thermistor and you are fine.

In both cases, makes sure both wires are the same length.

Three wires. The manual doesn't say anthing except that it is 0-99 degrees C.

Three wires is a thermistor (two for current, one for more accurate measurement with no voltage drop on the non-current carrying line. Two measurement lines for 4-wires is most accurate).

Thermocouples can also handle >300 degrees, and thermistors much much less. So it's a thermistor.

jackerbes and NKNguyen, thanks for your help. Anybody have any thoughts on my other questions?

Originally Posted by Lilienthal

jackerbes and NKNguyen, thanks for your help. Anybody have any thoughts on my other questions?

I don't have a charger that monitors temperatures so I just put my hand on the pack every once in a while. As long as it is not more than slightly warm to the touch everything is OK.

At 130F/54C you can no longer keep your fingers or hand in contact with a surface. And batteries are already becoming or soon will be permanently damaged at that temp or a little more. So I don't think I want to see a battery get over 110F or so in charging.

Jack