I’ve heard good things about Opus chargers (don’t remember if it was the BT C3400). About Litokala, not so much (at least as a brand).
Re: the BT C3400, I just googled and I think I found its manual: https://images-na.ssl-images-amazon.com/images/I/51TCfcbvBaL.pdf; gave it a cursory read and it seems not many parameters can be programmed (eg for discharge, only the discharge current can be set, and even so only at fixed values with large intervals among them).
There’s also the matter of precision, not sure how precise these chargers’ measurements are as (at least the for BT C3400) it seems the manufacturers do not indicate that.
Please let me know if you need assistance with interpreting it, it would be my pleasure to help.
Sure! It means a fraction of the battery capacity, which is indicated by the letter C. In that case, supposing the battery capacity is indeed 5800mAh (but please use the exact value in the datasheet), 0.2C would be 0.2 * 5800 = 1160 mA.
I want to make sure that when I report the values of a battery test, that I’m giving the best results I can based on my equipment and knowledge. Which are both lacking but much more in the knowledge category.
Presuming an official datasheet for the MJ1 can’t be found, I would try and use the values that the rewrapper (Vapcell) indicated for its F58 battery: https://www.vapcelltech.com/h-pd-174.html, that is:
Nominal capacity: 5800 mAh;
Maximum capacity: 5800*1.2= ~7000 mAh (in case your charger allows you to set that – for safety purposes during charging);
Cut-off voltage during charging: 4.2V (see below)
Cut-off voltage during discharge: 2.5V (a little too low for my tastes, but that’s what Vapcell indicates – I would employ it for testing but not for regular use).
Continuous Discharge current: 1.2A (from the notes after the first graph in the above page, the red line where it indeed reached 5800mAh during Vapcell’s testing; these same notes also confirm the cut-off voltages above);
I can’t find anywhere a spec for the charge termination current, but presuming it’s the same as my LG MJ1 (different size but same manufacturer and apparently the same or similar chemistry as per the “INR” prefix, so I think this is a reasonable assumption), it would be 50mA .
Which of these parameters can you set in your chargers?
On the BT C3400, presuming the manual I found for it is correct and the current can only be set at 200, 300, 500, 700, or 1000 mA, I would try with 1000mA, which is the one closest to the 1.2A the Vapcell spec page indicates.
I have had good luck with my liitokala lii-m4s. However it does tend to get warm and it doesn’t have a but the batteries don’t get hot. I keep an eye on it with my IR gun.
Glad to be of help! Let me know if you need anything else.
You certainly mean 1.2A, not mA
And yes, I agree: this capacity at 1.2A constant discharge is a very good number, my 3500mAh LG MJ1 for example, is specced at 680mA (about half of that, and with a larger-than-half C) for optimum discharge.
But most of what I know, I learned from our brothers and sisters here at BLF and previously at Reddit (RIP), so don’t be afraid and don’t get frustrated, just keep reading and asking questions!
For whatever it’s worth my Opus 3100 gives me about 10% more capacity then my Turnigy Accucel-6 on a discharge test. Obviously I can’t tell which, or even if either is, gives me the most accurate numbers
Do you have any VapCell H10s or LG MJ1s? If you do, I can do a test with my MC3000 and send you the numbers, then you can perhaps calculate an adjustment factor for your chargers.
I can’t explain why but my lii-m4s gives me a better charge/discharge for my batteries. I thought the opus would be better than my liitokala lii-m4s. I think some of might just come down to chance. I happened to get a liitokala that works great and others got an opus BT C3400 that works better.
