rebelrider.mike
Member
- Joined
- May 25, 2017
- Messages
- 554
I've seen a lot of questions regarding this charger, and I thought I'd make a thread that might answer them all in one place, and also offer my experience using it. Hopefully you all will offer your experiences and questionstoo.
So I've tested around 300 cells so far with the Opus, and I thought I'd offer some observations about it. I use it primarily to discharge cells for testing capacity.
Charge Mode:It doesn't seem to have the pre-charge mode where the cell is started charging at .1A until it reaches 2.9V or so. It jumps right into the constant current mode. Otherwise, it seems to charge fine.
Discharge Mode:I really like that it discharges cells to 2.8V. Other dischargers I've used won't do that. So I think this device is more accurate as far as capacity testing.
Discharge Refresh Mode: I haven't used this one. It would tie up the device for too long in my opinion. Also, I'm not sure if it works for lithium based cells. I think its more for nickle based cells.
Charge Test Mode: I'm not sure what this one is for. I read the manual, but it seems it does the same thing as the discharge mode? Maybe it recharges after?
Quick Test Mode: Measures internal resistance. Basically, a load tester with a bit of math involved.The general consensus is that internal resistance is not a particularly useful number since it doesn't really predict whether the cell is good or bad. Generally, low milliohms is good; like 100mOhm or so. Higher resistance like 500mOhms is less good. I've found that values over 800mOhms indicates a cell that is not in very good condition. This test also tends to give different numbers each time one cell is tested, so its hard to know the exact internal resistance anyway.
Some quirks and details about this charger:
- You can open the back cover and there's a little selector switch inside. It allows you to choose more varieties of battery chemistry for charging. Options are 4.2V (default), 4.35V (for high voltage cells), and 3.7V (for LiFePO4 cells).
- Although the charger has 6 temperature sensors and a fan, it still seems to get hot while discharging. I've found that just having a desk fan blow across it make a huge difference.
- It has a standard5.5mm x 2.1mm barrel connector, so you can plug it into any 12V DC power supply that can feed it enough amps.
- Make sure the power supply your using to feed the charger can give enough Amps to cover what you're using. Example, if you're charging all four cells at the default 500mA, you're 3A supply should be fine. But if you want to charge each cell at 1A, you may need to upgrade the power supply.
- When the charger gets hot enough, it will pause its function until the temperature goes down. I think it resumes automatically, but I'm not sure. The current display will read 000mA rather than 0mA, indicating a temperature interruption.
My own opinion is that this is a great little machine, and it has a very important place in my overall cell testing routine. Here's some quick pros and cons:
Pros:
- Best discharge/capacity tester I've used so far.
- Processes 4 cells individually, with independent settings.
- Can be used for a wide variety of cell chemistries and sizes.
- This single unit can run several different functions, and each slot can do those functions independently.
- Seems very reliable and is popular among us 18650 people.
Cons:
- No pre-charge mode. Overly discharged cells could be damaged by trying to charge them in this device.
- No way to calibrate voltage.
- No way to upgrade firmware.
- No storage charge function.
- Runs hot despite the internal fan. I've also heard the internal fan is prone to failure.
- No memory. Losing power means starting the discharge test over.
Finally, here's a few pictures I took the other day while messing around with it:
That's all I can think of for now. What's been your experience with this device? Also, post questions, and someone around here should be able to answer!
So I've tested around 300 cells so far with the Opus, and I thought I'd offer some observations about it. I use it primarily to discharge cells for testing capacity.
Charge Mode:It doesn't seem to have the pre-charge mode where the cell is started charging at .1A until it reaches 2.9V or so. It jumps right into the constant current mode. Otherwise, it seems to charge fine.
Discharge Mode:I really like that it discharges cells to 2.8V. Other dischargers I've used won't do that. So I think this device is more accurate as far as capacity testing.
Discharge Refresh Mode: I haven't used this one. It would tie up the device for too long in my opinion. Also, I'm not sure if it works for lithium based cells. I think its more for nickle based cells.
Charge Test Mode: I'm not sure what this one is for. I read the manual, but it seems it does the same thing as the discharge mode? Maybe it recharges after?
Quick Test Mode: Measures internal resistance. Basically, a load tester with a bit of math involved.The general consensus is that internal resistance is not a particularly useful number since it doesn't really predict whether the cell is good or bad. Generally, low milliohms is good; like 100mOhm or so. Higher resistance like 500mOhms is less good. I've found that values over 800mOhms indicates a cell that is not in very good condition. This test also tends to give different numbers each time one cell is tested, so its hard to know the exact internal resistance anyway.
Some quirks and details about this charger:
- You can open the back cover and there's a little selector switch inside. It allows you to choose more varieties of battery chemistry for charging. Options are 4.2V (default), 4.35V (for high voltage cells), and 3.7V (for LiFePO4 cells).
- Although the charger has 6 temperature sensors and a fan, it still seems to get hot while discharging. I've found that just having a desk fan blow across it make a huge difference.
- It has a standard5.5mm x 2.1mm barrel connector, so you can plug it into any 12V DC power supply that can feed it enough amps.
- Make sure the power supply your using to feed the charger can give enough Amps to cover what you're using. Example, if you're charging all four cells at the default 500mA, you're 3A supply should be fine. But if you want to charge each cell at 1A, you may need to upgrade the power supply.
- When the charger gets hot enough, it will pause its function until the temperature goes down. I think it resumes automatically, but I'm not sure. The current display will read 000mA rather than 0mA, indicating a temperature interruption.
My own opinion is that this is a great little machine, and it has a very important place in my overall cell testing routine. Here's some quick pros and cons:
Pros:
- Best discharge/capacity tester I've used so far.
- Processes 4 cells individually, with independent settings.
- Can be used for a wide variety of cell chemistries and sizes.
- This single unit can run several different functions, and each slot can do those functions independently.
- Seems very reliable and is popular among us 18650 people.
Cons:
- No pre-charge mode. Overly discharged cells could be damaged by trying to charge them in this device.
- No way to calibrate voltage.
- No way to upgrade firmware.
- No storage charge function.
- Runs hot despite the internal fan. I've also heard the internal fan is prone to failure.
- No memory. Losing power means starting the discharge test over.
Finally, here's a few pictures I took the other day while messing around with it:
That's all I can think of for now. What's been your experience with this device? Also, post questions, and someone around here should be able to answer!