Cell Charger / Tester Summary

Detritalgeo

Detritalgeo

Member
Joined
Nov 29, 2017
Messages
34
I have noticed there are a variety of units being used for charging and testing capacity. I have not been able to find a thread with a summary of the most common with specs.

I also noticed many dischargers have different cut-off voltage for capacity testing

Perhaps this can be started here, I don't have them all but I can try to compile of the admins can take this over as a sticky if it proves to be a good reference.


1) TP4056 / micro-USB PCB module

Size: 1 cell (must purchase cell holder separately)
Overheat Detection: NO, do not charge cells unattended / overnight

Charging: YES
Charge Current: 1000 mA x 1 cell
Charge Voltage: 4.20 V
Charge mode: CC/CV
Charge Status LED: YES
Charge Complete Beep: NO

Discharging: NO
Discharge Current: NA
Discharge Cut-off: NA
Discharge Mode: NA
Discharge End BEEP: NA

Measure Internal Resistance: NO

Nominal Cost: 0.2 - 0.5 USD per board

Retailer: Ebay, AliExpress, Amazon, Gearbest

Misc. Comments:
- cheap and easy, simply plug into and 5V USB port
- at least 2 versions, 1st without reverse polarity protection and second with (pictured)

Image:
[img=250x200]http://www.communica.co.za/Content/Catalog/Images/I4153156114.jpg[/img]
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2) NITECORE DigiCharger D4

Size: 4 cell
Overheat Detection: YES(however, no stated cut-off temp, do not charge cells unattended / overnight)

Charging: YES
Charge Current: 375 mA x 4 cell, 750 mA x 2 cell
Charge Voltage: 4.20V
Charge mode: CC/CV, ~50 mA cut
Charge Status LED: YES
Charge Complete Beep: NO

Discharging: NO
Discharge Current: NA
Discharge Cut-off: NA
Discharge Mode: NA
Discharge End BEEP: NA

Measure Internal Resistance: NO

Nominal Cost: ~$20-30 USD

Retailer: Ebay, AliExpress, Amazon, Gearbest

Misc. Comments:
- good build quality, LCD read out of voltage, charge current and charge time

Image:
[img=286x200]http://img1.indafoto.hu/10/3/3093_5..._92908f988d7fb89e89cff0138fc732a2_l.jpg[/img]
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3) OPUS BT C3100 (v2.2)

Size: 4 cell

Overheat Detection: YES (however, no stated cut-off temp, do not charge cells unattended / overnight)

Charging: YES
Charge Current: 200 mA, 300 mA, 500 mA, 700 mA, 1.0 A (1.5 and 2.0 A if only bay 1 and 4 used)
Charge Voltage: 4.20V
Charge mode: CC/CV
Charge Status LED: LCD Display
Charge Complete Beep: NO

Discharging: YES
Discharge Current:200 mA, 300 mA, 500 mA, 700 mA, 1.0 A
Discharge Cut-off: 2.80 V
Discharge Mode: CC
Discharge End BEEP: NO

Measure Internal Resistance: YES

Nominal Cost: ~$20-30 USD

Retailer: Ebay, AliExpress, Amazon, Gearbest

Misc. Comments:
- fan operation is 'not quiet'
- unit known to overheat and suspend charge/discharge, can upgrade fan
- 'auto cell test' function (charge-discharge-charge, mAh displayed)
- Internal resistance measurement known to have poor precision, gives result for general 'health' only (see post #13)

Image:

[img=300x200]https://eu.nkon.nl/magento17/media/...b8d27136e95/o/p/opus-bt-c3100-empty.jpg[/img]
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3) FOXNOVO 4S

Size: 4 cell
Overheat Detection: NO?

Charging: YES
Charge Current: 500 mA, 1.0 A (selectable for all, not independent)
Charge Voltage: 4.20V
Charge mode: CC/CV
Charge Status LED: LCD Display
Charge Complete Beep: YES

Discharging: YES
Discharge Current:500 mA, 1.0 A (selectable for all, not independent)
Discharge Cut-off: 2.70 - 2.80 V
Discharge Mode: CC
Discharge End BEEP: YES, cannot be turned off

Measure Internal Resistance: NO?

Nominal Cost: ~$20-30 USD

Retailer: Ebay, AliExpress, Amazon, Gearbest

Misc. Comments:

Image:


[img=200x200]https://i.ebayimg.com/images/g/kyMAAOSwpONZQw4L/s-l300.jpg[/img]
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4) SKYRC MC3000

Size: 4 cell
Overheat Detection: YES, selectable cut-off temp per cell, fan activation temp also selectable

Charging: YES
Charge Current: selectable from 0.05A - 3.00A
Charge Voltage: selectable from 3.40V - 4.40V with storage option
Charge mode: CC/CV
Charge Status LED: 128x64 LCD Display
Charge Complete Beep: YES, selectable

Discharging: YES
Discharge Current: selectable up to 2.00A
Discharge Cut-off: selectable (2.50V - 3.75V)
Discharge Mode: CC or CC/CV selectable, selectable mA cut
Discharge End BEEP: Yes, selectable

Measure Internal Resistance: YES

Nominal Cost: $75 - 100 USD (depending on coupon code)

Retailer: Gearbest

Misc. Comments:
- USB connection for remote control by PC
- Bluetooth connection for remote control by phone/tablet
- compatible with standard 3.7, 4.20 and HV 4.35 cells
- Firmware updatable
- very reliable voltage and current values
- very reliable thermal cut-off if a cell begins to heat

Image:



image_puiaqf.jpg

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5) MiBoxer C4-12

Size: 4 cell independent
Overheat Detection: YES, shut-down if cell > 70C

Charging: YES
Charge Current: 0.1, 0.2, 0.3, 0.5, 0.8, 1.0, 1.5, 2.0, 2.5, 3.0 A or 'Auto'
Charge Voltage: 4.20V only
Charge mode: CC/CV
Charge Status LED: LCD Display
Charge Complete Beep: NO?

Discharging: YES
Discharge Current: ?
Discharge Cut-off: ?
Discharge Mode: ?
Discharge End BEEP: ?

Measure Internal Resistance: YES?

Nominal Cost: $45 - $60 USD

Retailer:
Gearbest - https://www.gearbest.com/chargers/pp_1044646.html?vip=3932164
...Ebay, Amazon, AliExpress

Misc. Comments:
- USB port for external charging via cell in slot 4
- Automatic charge current based on cell IR
- Automatic capacity testing
- 'automatic repair' of 0V Li-ion cells
- high precision voltage reference
- charge in your car by 12V plug
- fireproof plastics

Image:

[img=300x300]https://b2brazil.com/sites/default/...uct/image/1_fu_ben__3.jpg?itok=pH3O7j77[/img]
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6) Enova GRYfalcon 88

Size: 8 cell
Overheat Detection:NO?

Charging: YES
Charge Current:
Charge Voltage: 4.20V, 4.30V, 4.35V
Charge mode: CC/CV
Charge Status LED: LCD Display
Charge Complete Beep:

Discharging: NO
Discharge Current:
Discharge Cut-off:
Discharge Mode:
Discharge End BEEP:

Measure Internal Resistance:

Nominal Cost:

Retailer:

Misc. Comments:

Image:

[img=267x150]http://blog.enova18650.com/wp-content/uploads/2016/06/Gyrfalcon-All-88-Angelo.jpg[/img]
 
and it's a TP4056, not TP4605 ;)

Another thing to note is that there is a percentage of inaccuracies compared to each other. I think it can be as much as 10% variance between testers. The TP4056 board does a pretty decent job of actually going to 4.2V

Good collection of stats, btw.
 
Palamedes said:
Can someone explain CC/CV
Click to expand...

Charging starts as constant current (CC) (e.g. 1 amp).
once the cell reaches 4.20 V, the charging switches to constant voltage (CV) and drops the charge current to go no higher than 4.20 V.
 
CC and CV are methods of charging and discharging cells, especially important for lithium cells.

CC is constant current, CV is constant voltage. You can see this when looking at the charging process of a lithium cell on a suitable lithium charger, in the first stage it charges with a constant current. This means the current is limited to match the spec of the cell and is kept constant while the voltage goes up. When the voltage hits the end of charge voltage the charger changes from CC to CV and keeps the voltage constant while the current drops.

This is important because you can't fully charge a lithium cell when using CC or CV alone.
With CC you will either not be able to fully charge the cell when cutting off charging at 4.2V. Or, if you continue with CC, you will damage and eventually destroy the cell by raising its voltage above the specs.
With CV you risk damaging or eventually destroying the cell, especially when it is fully discharged, by forcing a large initial current through it.
That is why you need CC and CV to fully charge a cell without damaging it, you can't achieve that with either of both alone.

While discharging this is important as well. A CC discharge will give other results as a CV discharge when using the same cell. A CC discharge is much closer to reality. Still not perfect, but good enough. It will tell you what the usable capacity of the cell is. And depending on the cell and its specs and condition it won't be empty at the end of the discharge. Just like you can't fully charge a lithium cell with CC alone you can't fully discharge it with CC either. A CV discharge will tell you the total capacity of the cell but it doesn't tell you how much of that capacity is actually usable. Usable in this case refers to the voltage of the cell. As soon as the cell drops to 3.0V under load you should end the discharge. A good cell will drop to 3.0V under load only when it is as good as fully discharged. A bad cell will drop to 3.0V instantly without using any meaningful amount of its capacity.

By the way, ever seen advertising on battery powered devices like "80% capacity rechargeable in 30 minutes" or something? That has to do with CC and CV. CC can be used to recharge a big part of the capacity very quickly. The CV part takes time and is completely optional of course when you don't care if the battery reaches 100% or not. If you want to put some charge back into the battery as quickly as possible to use the device again you do CC only and that often means you can't get more than 80% because you have to do CV for the last 20%.
 
Liken it to when filling a bottle up with water. When it's empty, the faucet is on full blast (CC), then as it reaches the top portion you slow it down so you won't over fill it (CV)
In this example, CC = force of water, or water pressure. CV = speed of water, or water flow. The two must work together to move water, or electrons, to its destination. You can't have charging, or filling, with one or the other.
 
I wanted to add in this one, it's one of the only ones I've seen which can do 1.5A charging/discharging though it's only 2 cell: http://lygte-info.dk/review/Review Charger Miboxer C2-4000 UK.html

I've been happy with it so far, but one thing I've noticed is the capacity is 5% lower than what an Opus says. Haven't found out yet whether this is just something like Peukert effect from running at 1.5A or if it's just inaccurate. I also have a Zanflare C4 which I picked up on sale but I didn't realize it can only do 500mA in discharge test which takes forever (~15 hours for a full nor cycle of a 2.2AH cell) so it's just beingused as a normal smart charger for me since at least it does that at 1A.
 
Since the Opus generally produces results that are deemed a bit high it might be a good thing to be 5% below the Opus :)
 
Update, looks like it's not related to the current on the MiBoxer. Got a consistent result of 1918 mAH at 1A setting vs. 1930 mAH at 1.5A setting. The higher reading at higher current was likely due to self-heating, since warmer cells have better discharge capacity (albeit shorter lifespan). I'll have another result in a bit also.
 
One thing about the OPUS though. Their internal resistance readings are way off due to high contact resistance.

One better option would be a dedicated internal resistance tester like this one:
https://www.ebay.ca/itm/Digital-Bat...330660?hash=item3ac85842e4:g:O4wAAOSwj2dXkCDo

A bit expensive at 38$, but worth for some high current applications with little cells.

This tester at 9$CA that I bought does the job very well and accurately using modified cell holders, with the springs bypassed with 18AWG wire:
https://www.ebay.ca/itm/ZB206-V1-3-...hash=item5b410ecd1d:m:m-fDlCi4_CjzePPvjpSw0Zg
 
Yes, internal resistance is a tricky one, most devices have poor precision that may be due in large port to the connection types, especialy magnets or springs vs. solder or weld..

I added comment to the opus section.
 
Finished benchmarking my 3 chargers by repeat testing 15 cells between my MiBoxer C2 4000 and Zanflare C4, and another 8 cells between my MiBoxer and Opus BTC-3100 v2.2. Results show fairly consistently that the Opus measures 6% high, and the Zanflare measures 5% high. The standard deviation is 2.4% for the Zanflare and 1.5% for the Opus (assuming the MiBoxer as the "true" baseline). Note these values are with a modified higher flow rate fan on the Opus. The standard fan may give slightly different results.
 
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