Eagle Tree reading below 5V
 

So I have 15 18650 cells and I was making a 3S5P power source. I noticed that the output should have been at least 6Ah, but I would only get about 3.5Ah. I ended up taking all the cells apart to match them. I decided that I would use my Eagle tree in series with my charger and battery and just log the info on my computer. I know it doesn't work below 5V but if I am in live mode monitring it has anyone tried this?

Jeff

What was the cut-off set to during your discharge? You're only taking 700mAH from each cell, which I am assuming is rated for 1.1AH.

Sorry I don't know anything about Eagle Tree stuff........ :whistle:

They are 2200 mah cells and there are 5 in parallel, for a total of 11 ah. Figuring that the cells are pretty well used I am going to shoot for a more realistic 1.6 ah for each cell and 8 ah.

I took them apart and had a single cell that shot up to 5 volts and when you measure it with a DMM the voltage drops, so I found my bad cell.

The cutoff was set for 3.0V per cell.

Jeff

edit: The other thing was that the other 2 5p cells were getting about 5200mah at a 5 amp discharge. The other 5p cell, the voltage would increase a lot faster during charging and it would drop faster during discharge.

Oh, OK. There was a bad cell after all... I had no idea they made the 18650's in 2200mAh. So then why are A123 26650s only 2300mAH? I feel robbed... :smile:

They actually make the 18650's in lots of flavors. There are several different makers. Most of the ones I am seeing are in the 2000-2600mah range. These aren't like the A123's most are between .8C-2C discharge rate, but they are good for some some stuff I have been using them for. Cheap cordless drills, flashlights, and this one is for a 12V power source for a 50W inverter and 12V plug. It had a 12V 4ah battery in it, but it died a long time ago.

Jeff

I got it to work a few times. but the charger kept faulting out saying the battery was not connected, and I would see open circuit voltage around 22V. Not real sure if it was a connection or not.

Jeff