Give your opinion on different chargers

m6yru

m6yru

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Sep 6, 2017
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Howdy-do-it all....
can you all put down your opinions on;
1, your favourite charger (company and model)and why,
2, a charger you would recommend a newbie to buy because its easy to use,
3, what charger have you used that you would tell people to stay away from!

This i think will be interesting
 
Oh dear, this is much more complex than you would maybe think. It completely depends on what you want to do. I've had so many chargers over time and still have several that I can't name a favorite. They all have different properties which makes them useful in their certain area.

Same goes for recommendations, you can't recommend something without knowing what the requirements are. If it is all about easy operation than...well...I think I have never come across a charger that is difficult to use. Well, apart from some older RC chargers with horrible user interfaces.
 
What do you want in it?
1. Different charging voltages/amperage?
2. Capacity testing?
3. Portable(Micro-USB powered)?
4. Size?
5. Data report on SD card/USB Drive?
6. Cost?
 
this is where i wanted you'll to give your opinions on the chargers you have used, the one you love the one you hate etc :)
 
For 18650 cells:

Opus because its simple and just give you numbers that works. Its not the cheapest. I have tested many of the other ones and i got stuck with the opus as a decent choice.

For all other and for proper testing
iCharger DUO 308 or 4010.
Because they just rock! Dual ports and you can do heavy capacity testing. I use this for everything

Lead acid generall
Ctek one of their bigger asses....

And then to go into detail as Dark said there is one for each purpose :) And i probably have 10 different in total :D
 
Personally, for charging only, I use my TP4056 bank for charging and voltage recover. With this, I can process cell batches rather quickly, though it does take much more time for smaller batches, since I have to capacity test them separately using a boost converter and resistors.

For bulk testing, I just use 5x18650 powerbanks that I bought a while back to capacity test them without costing through the nose using an OPUS. This also gives me more realistic capacity tests, since they are done at a constant voltage. Though this method results in less perceived capacity, as there are losses from 3-4.2V to 5V, it also means I'm building an overkill pack with more capacity than I'm thinking.

All in all, DIYing it cost me less than half of an OPUS in C$, and I can test so many more cells.
 
Charging individual 18650s in big numbers: Array of TP4056
Charging individual 18650s in small numbers and/or with protection PCB: SkyRC MC3000 which I got only some days ago, love it already
Charging NiMh/Eneloop: Technoline BC 700 until recently, now also MC3000
Charging parallel 18650s (known same voltage and/or capacity): SkyRC D400
Balance charging batteries or generally charging anything big, including lead acid batteries: SkyRC D400

Maintenance, also off-site: SkyRC IMAX B6AC v2
Reviving dead cells: PeakTech 6225A lab powersupply (runs on AC) or Ruideng DPS5020 (runs on DC) as soon it arrives, both are CCCV power supplies

Discharging for capacity testing: SkyRC IMAX B6AC v2 and B6 Mini until recently, now MC3000

Generally I'm satisfied with most SkyRC products, this is a relict from my RC days. Some, if not most, are rebranded Hitec units. As are some Turnigy chargers for example, but Hitec doesn't sell products under its own brand world wide. I'm thinking about getting some Junsi chargers as well, they have models for up to 10S and some with way more power than my D400 has. So once there is a use case I'll probably extend my fleet of devices once again.
 
I have the following:
-Opus C3100 v2.2: highly recommend for the reasons listed above
-SkyRC IMAX B6 mini: I haven't been terribly impressed with this. Trying to charge 4p takes forever. It also appears that it can't do more than 1s without a balance input. Need to figure out what I'm doing wrong.
-Qty 2 no-name 4.2v .1v 4-bay chargers from eBay: need to closely monitor these to prevent overcharging. I use these mainly to boost cells to ~4v and finish with one of the two above.

I'm planning to also go the TP4056 route, but still need to find the LED voltage indicators referenced somewhere on this site.

I would like to find a decent charger to do multiple voltages (12/24/36/48v) without pulling packs out (like in a scooter, for example), as I'm building e-bikes and go karts.
 
hookemdevils22 said:
I have the following:
-Opus C3100 v2.2: highly recommend for the reasons listed above
-SkyRC IMAX B6 mini: I haven't been terribly impressed with this. Trying to charge 4p takes forever. It also appears that it can't do more than 1s without a balance input. Need to figure out what I'm doing wrong.
-Qty 2 no-name 4.2v .1v 4-bay chargers from eBay: need to closely monitor these to prevent overcharging. I use these mainly to boost cells to ~4v and finish with one of the two above.

I'm planning to also go the TP4056 route, but still need to find the LED voltage indicators referenced somewhere on this site.

I would like to find a decent charger to do multiple voltages (12/24/36/48v) without pulling packs out (like in a scooter, for example), as I'm building e-bikes and go karts.
Click to expand...
in reality the tp4056 seems to me just like a buck converter, takes the 5v and applies 4.2v to the cell...
if thats the case (can someone tell me if im wrong) that you should be able to use a buck/boost converter to charge the other cells without BMS.... so for a 12v system the max charge is 12,6v (3s).... 25.2v for 24v (6s)..... 37.8v (9s) anything after this is usually beyond the basic buck/boost converter voltage...

i have ordered a c3100 but its gotta come from china.... sigh
 
Well, you are wrong :D

Your observation isn't completely wrong though as probably all chargers have buck/boost DC-DC conversion technology built in. However, you are completely missing the point. Just because something does DC-DC conversion it doesn't mean it is just a DC-DC converter. A DC-DC converter is strictly an unintelligent device converting between its input and output. The TP4056 is an IC, it is a microcontroller. There is also DC-DC conversion happening on the board, this is necessary for it to work, but the TP4056 brings all the logic to make charging a fully automated process.

That said you can charge lithium cells with any CCCV power source as a manual process. Most buck/boost converters and lab power supplies are suitable for the job. This works for single cells as well as serial configurations if the voltage is set correctly. However, obviously there is no balancing happening. This is something a smart charger, like a TP4056, would do for you. The TP4056 itself obviously wouldn't do it as it is set up for 1S, but you get the point. This category of device would do it in contrast to a simple DC-DC converter.

You can easily buy 10S smart chargers/balance chargers off the shelf than can handle 12V, 24V and 36V batteries. The RC folks will have you covered on that one, above that there are 48V chargers for ebikes, I think. However, these aren't usually balance chargers but merely AC-DC converters with CCCV.
 
DarkRaven said:
Well, you are wrong :D

Your observation isn't completely wrong though as probably all chargers have buck/boost DC-DC conversion technology built in. However, you are completely missing the point. Just because something does DC-DC conversion it doesn't mean it is just a DC-DC converter. A DC-DC converter is strictly an unintelligent device converting between its input and output. The TP4056 is an IC, it is a microcontroller. There is also DC-DC conversion happening on the board, this is necessary for it to work, but the TP4056 brings all the logic to make charging a fully automated process.

That said you can charge lithium cells with any CCCV power source as a manual process. Most buck/boost converters and lab power supplies are suitable for the job. This works for single cells as well as serial configurations if the voltage is set correctly. However, obviously there is no balancing happening. This is something a smart charger, like a TP4056, would do for you. The TP4056 itself obviously wouldn't do it as it is set up for 1S, but you get the point. This category of device would do it in contrast to a simple DC-DC converter.

You can easily buy 10S smart chargers/balance chargers off the shelf than can handle 12V, 24V and 36V batteries. The RC folks will have you covered on that one, above that there are 48V chargers for ebikes, I think. However, these aren't usually balance chargers but merely AC-DC converters with CCCV.
Click to expand...
yes the bike chargers are just a PSU as all the electronics and BMS circuit is in the battery pack so what i have found in the ones i dismantled
 
I have a SkyRC AC charger. An imax B6 clone and a HK RC charger. All for initial charging. I have just one opus for capacity testing. I may have to get another soon. I have an array of TPs to deploy. Just venturing into the 18650 world. I have a lot of experience with LiPo batteries.

To be honest, none of my chargers are any 'good' at all. They are great for my needs. They are cheap, easy to use and accurate where accuracy matters. They require user knowlage and intervention to do a good job, but hey, nobody charges second hand batteries without monitoring them.

When I have time, I shall code an Arduino to do the work for me. No matter what you spend on BMS aside maybe Batrium, you don't have a fullly customizable system. As i am on a tight budget Arduino is my solution.
 
I'm waiting on a set of 4 ofthese capacity testers, which will be connected to 4-pack cell holders wired individually. A set of 4 are much cheaper than another Opus, and can easily be wired for prismatic or pouches, whereas the Opus is limited to 18650.

I'm interested to see what you can do with an Arduino. My long-term goal is to have a relatively standardized BMS for e-bike, powerwall, e-go kart, etc.
 
The problem with these capacity testers is that you need a constant current load to get the real capacity, as the voltage of the 18650 drops, the current drawn drops too.
 
That's why I'm gonna build my version of MrConstantin's testers. I want that CC as well and so far, he's got a pretty darn good setup.
 
BlueSwordM said:
you need a constant current load to get the real capacity
Click to expand...

Why is that a problem?

"as the voltage of the 18650 drops, the current drawn drops too."

I can see that if the meter assumes that current stays the same, then it would overestimate, however, if you are using the same test on each cell, are the results still going to work for making similar capacity packs?

If the meter measures current and voltage, then it should give an accurate result.

Does anyone know how those testers work?

I understand that if you use 1amp constant discharge, you will get a smaller result than if you use 1/2amp, so 2 constant discharge tests with different parameters will give different results too.
So which is the real capacity?

In service, the packs will have varying loads on them too?
Would charging and discharging at similar currents (peak currents?) to what the cells should be seeing in service be beneficial in any way?
 
There is no such thing as a "real" capacity. The closest is the capacity at the discharge rate specified by the manufacturer in the datasheet. That is usually a rather small rate and therefore close to the total capacity of the cell.

As long as the results aren't completely wrong you can use them since the relation stays the same, that is correct. However, without a constant current load the results WILL BE terribly off, i.e. wrong. I've picked only a few cells to test this and it didn't take long to find examples that showed differences of 50%. You don't want a margin of error of 50%.
 
DarkRaven said:
There is no such thing as a "real" capacity. The closest is the capacity at the discharge rate specified by the manufacturer in the datasheet. That is usually a rather small rate and therefore close to the total capacity of the cell.

As long as the results aren't completely wrong you can use them since the relation stays the same, that is correct. However, without a constant current load the results WILL BE terribly off, i.e. wrong. I've picked only a few cells to test this and it didn't take long to find examples that showed differences of 50%. You don't want a margin of error of 50%.
Click to expand...

I think relative capacity is fine. So long as you use the same cup to measure a cup full. A cup is a cup. Simple as that. So long as you use the same measure to gauge capacity it doesn't matter the method
 
That is true but still you don't want huge gaps between reality and your measurements. Your calculations are based on your measurements and if these are terribly wrong then your calculations are as well. You size your batteries by choosing the amount of cells, capacity, current / distribution of current over the cells, runtime and so on. And if these decisions are based on measurements with 50% error, well, that's not good.

You can live with 10% or so. That's what everbody who uses an Opus is doing. You certainly don't want more than that. Only at that point is your cup still a cup. Otherwise it becomes a bucket :D
 
The more I think about it, the more I am not sure....

If measured capacity is "out" by the same percentage across all cells, then I dont think there should be any problem - all your packs will end up the same capacity.

If the measured capacity is "out" by a larger proportion on higher or lower capacity cells, then you might end up putting packs together that are not the same capacity.

eg pack made up with cells actual capacity of
1800, 1800, 1800, 1800 = 7200mah
1600, 1600, 2000, 2000 = 7200mah

If testing gives consistent 10% over, then measurements would be
1980,1980,1980,1980 = 7920mah
1760,1760,2200,2200 = 7920mah

everything will end up consistent.

If measurement error in not consistent across the range, you could end up with something like testing is 10% over at 2000mah, 5% over at 1800mah and accurate at 1600, then measured results would be

1890,1890,1890,1890 = 7560mah
1600, 1600, 2200, 2200 = 7600mah

Maybe this type of error is more likely in the non-constant current tester?

I have some of the zb2l3 testers coming. I will have to find out more about them.
 
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