charger under $20 that shows voltage and lets me set current?

Batteries and Chargers Chargers
1

charger under $20 shows voltage and lets me set current

is there such a thing?

multiple cells would be nice but not necessary

thx
wle

2

You could use an inexpensive adjustable power supply to perform CC/CV charging. Do you have one?

A quick look at the RD Tech store shows this $15 device: RD DP30V5A-L
RD DPS3003 is $25.52 at the moment, so it’s a bit over budget.
I’d rather have the new RD RK6006 though, which is $36. Way over budget.

These devices are a lot more versatile than only a charger would be, which could justify the cost.

3

right - thanks but i don;t want to do all the work myself :slight_smile: monitor and set everything

i do have them at work

4

XTAR VC2L/VC2SL. The SL is an upgraded version with a few extra features (IR measurement, powerbank) (version comparison), either let you choose between 2A (single battery at a time), 1A, or 0.5A charge rate. I have a VC4SL which goes lower (3/2/1/0.5/0.25A), but doesn’t have a powerbank mode… XTAR’s specs are all kind of confusing. In general. 0.5A is fine for any battery, good 18650s and up will take 1A fine, good 21700s can take 2A but that’s a bit too hard for routinely charging 18650s IMO (I’d use 2A with a Molicel or Samsung 18650 in an emergency). I usually use 1A for everything except 0.5A for 14500. The main time you’d want 0.25A or less is trying to save an overdischarged battery, but the Xtar chargers have an automatic mode for that anyway.

5

Ok, but just to clarify the charging procedure when using a benchtop power supply: for charging a single liion cell, you’d set the voltage to 4.2V and set the current to whatever your desired max charge current is, such as C/2 or C/3.

Typical liion datasheets specify a charge cutoff value of C/20. So for a 5,000mAh cell, you’d stop the charge when the current dropped to 250mA. Your average liion charger performs the cutoff at ~100mA, so it’s not a particularly critical value. At least one cell specifies a cutoff current of .01C in the datasheet (Pytes/DLG INR18650-320) which for that cell is a cutoff of just 35mA.

What if you don’t want to consider the cutoff value at all?

You can avoid monitoring the cutoff completely if you set the voltage to 4.05V, which is the “float charge” value recommended by Samsung for liion cells.

6

You could DIY something but just spend the extra $5-10 and get a vc4sl

7

Yeah, this is possible, but AFAIK, the only charger currently available that can do that is the SkyRC MC3000.

8

I bought this as an adjustable source, but the ammeter only works to check the battery charge.

Of the three it is the one on the display.

I used an external multi turn potentiometer but if you only use it for one value it is easy to turn with a screwdriver.

But it is more convenient to use a specific charger.

I leave you the link remember is the one that carries the two lcd so you see the charge voltage and current.

Convertidor de potencia XL4015 5A CC a CC, controlador LED CC CV, placa de carga reductor, mĂłdulo de cargador de litio, Original

Sorry I didn’t read this, I bought an Opus BT-3100 but it arrived defective so I can’t comment.

I like the Sky better but I haven’t tried it either.

9

My post was about charging with a benchtop power supply, and how it is possible to do so without the need to monitor the termination current. Regular liion chargers perform a cutoff automatically, typically at 100mA or so.

10

OP is asking for a charger that will allow manual current selection.

While the VC4SL (VC4 Plus) allows for that, the VC2SL does not. It meets the budget criteria, but not the other.

I generally like XTAR but they have too many similar models in the lineup, including the older ones, and marketing the VC4SL/Plus under two different model names doesn’t help. Not to mention the Allmaybe brand, which they have seemingly put out of its misery.

I also distrust the automatic wizardry and lack of control on the more modern ones, based on my older model that has never fulfilled its performance promises.

Since I gave away my MC1 that I use most often, I’m considering an FC2, which does have manual current selection, via a hardware switch, and Type-C input, without the QC shenanigans they’re playing with the other models.

Just an inexpensive, basic charger that handles the fundamentals well, offers some control, and provides enough information to monitor progress. Those fancy displays can be hit or miss in terms of accuracy anyway.

11

I save the link I like them. :hugs:

Thanks.

What about the Lii-500?

It fits your budget and 300mA-500mA-700mA-1000mA charging modes.

I don’t know if it’s what you were looking for and with the deals these days on AliExpress you could buy it for well under $20.

Likewise I can’t speak about it, but I see it in many post when they show their pictures charging batteries.

12

that is what i had, lii-500, it quit after about 6 years

now there is an lii-pd4 that seems a little better, $17 or so, so i ordered that from ali

1 Thank
13

Dunno the VC2L but the VC2SL have -like some other Xtar- only the ability to set max. current, the charger itself decides if it use your selected current.

My VC4SL is very picky, it could be I select 2A and it use only 0,5A

14

Because it thinks the battery IR is too high for 2A

1 Thank
15

I use 3 of these for some years, and they ‘show (and let me select) voltage’, and let me ‘set current’.

You may have other unspecified requirements which rule it out, but it does those 2 things…

Personally, I’d probably be afraid to even use a charger costing <$20 USD. This one comes close but that’s because it’s out of production and is not in the current product lineup.

2 Thanks
16

That’s most chargers. It’s a safety feature, when it detects high IR. So you don’t accidentally dump 3A into a 10400 or something. If you want to force a current, be extremely sure you know what you’re doing, and probably can on the MC3000, I’d guess.

17

you couldn;t get 3A in though, the volts would be too high… right?

18

The charger will limit the voltage to 4.2V max. Whether or not the cell would accept >3A depends on the state of charge, and presumably the cell’s internal resistance.
Normally when a cell is charged, the charger may spend some time in the constant current (CC) range, pegged at the selected current, and the voltage is variable as it climbs up to 4.2V. Once it hits 4.2V it transitions to constant voltage (CV) and the current starts to drop. Depending on the cell’s state of charge and internal resistance, and the selected current limit, the charge cycle may start in the CV range. If there were no current limit, the cell would take whatever current it can at 4.2V. Theoretically if you were to provide an even higher voltage, the cell would take more current, but you should never provide >4.2V (+/- .05V) to a liion cell for risk of catastrophic failure.

2 Thanks
19

Sure you can. It’ll try to anyways. Like @Hoop says above.

Unless youre asking will it get 3ah into the battery. Then no.

20

I know, but I want to charge with the selected current :slight_smile:

Most chargers? Maybe Xtars.

I have/had 3 chargers from Opus, The Vapcell S4+, Skyrc NC1500, Nitecore Um2/UMS4, Dlyfull A4 and T5, Keeppower L4, Zanflare C4, ISDT C4 EVO and some others.

Only the VC4SL override my selection.

Opus, Nitecore, Keeppower decrease the current near the end of charging but don´t patronise me directly at the beginning. Maybe some chargers will also decrease the current because of temperature, but never had this problem.

Many of my AA-NiMHs have no problem charging at 1A with my other chargers, only the VC4SL have such problems. But because it´s a general bad NiMH-charger I rarely use it.