Is my charger defective?

[chazzmacs]

I’m a newbie, bought an Ovonics X1 Pro as it seemed to be well regarded, but I’m puzzled. I’ve got batteries that need to be dropped to storage voltage, sink the winds have been up, and I plug the batteries in to the charger, select Storage as a task, set voltage at 3.0, and whatever amps I select, when I start the task, it goes for a while, voltage in each cell drops past 3.8, then goes back up to around 3.94. The percentage then stops moving, and nothing happens for an hour or more. The unit isn’t hot, I can’t see any reason for this, and I need to know if this is defective or if I’m not doing it right.

 

[RetroThutmose]

I’m a newbie, bought an Ovonics X1 Pro as it seemed to be well regarded, but I’m puzzled. I’ve got batteries that need to be dropped to storage voltage, sink the winds have been up, and I plug the batteries in to the charger, select Storage as a task, set voltage at 3.0, and whatever amps I select, when I start the task, it goes for a while, voltage in each cell drops past 3.8, then goes back up to around 3.94. The percentage then stops moving, and nothing happens for an hour or more. The unit isn’t hot, I can’t see any reason for this, and I need to know if this is defective or if I’m not doing it right.

Yes that's a healthy storage voltage.

 

[chazzmacs]

Yes that's a healthy storage voltage.
View attachment 248327

I’ve seen 3.8-3-85v as the best storage voltage. I have the charger set to 3.8, so expect it to get closer to that. My question is it normal behavior for this charger?

 

[RetroThutmose]

I’ve seen 3.8-3-85v as the best storage voltage. I have the charger set to 3.8, so expect it to get closer to that. My question is it normal behavior for this charger?

Yes. The battery has voltage sag, it trips the cutoff and the the battery levels out a bit higher when no longer under a draw.

 

[chazzmacs]

So in the case of these little 2S batteries, I have to continually restart the task, I take it. What a pain in the butt!

 

[RustyUs]

I know if I'm discharging a pack that is fully charged, and it won't be used for the day/evening, I'll bring the cell voltages (under 15~20A load using separate resistors) down to 3.6-ish volts/cell. After disconnecting the load, the cell voltages will bounce back up close to my target 3.8v/cell storage voltage. If I was in your situation, and had to use the internals of the charger to discharge a pack, I'd use the Discharge function and set ending voltage 3.7v/cell to see where the cells bounce back up to.

 

[RetroThutmose]

So in the case of these little 2S batteries, I have to continually restart the task, I take it. What a pain in the butt!

no, what are you talking about. set it to storage and when it's done it's done. you don't need to have scientifically precise voltage. it's close enough.

 

[chazzmacs]

I know if I'm discharging a pack that is fully charged, and it won't be used for the day/evening, I'll bring the cell voltages (under 15~20A load using separate resistors) down to 3.6-ish volts/cell. After disconnecting the load, the cell voltages will bounce back up close to my target 3.8v/cell storage voltage. If I was in your situation, and had to use the internals of the charger to discharge a pack, I'd use the Discharge function and set ending voltage 3.7v/cell to see where the cells bounce back up to.

Thanks! I’ll try that.

no, what are you talking about. set it to storage and when it's done it's done. you don't need to have scientifically precise voltage. it's close enough.

ill give it a try, thanks.