Test/review of Vapcell S4+ fast charger

Finally we have this review.

Many thanks again…

I have no idea.

Finally? It takes time to record about 50 curves.

Don’t get me wrong. You mentioned you have been testing this charger for a few weeks. Many of us are eagerly waiting for your hard work to be completed.

Once again, thanks for the hard work.

Seems to me it would be safer if the error was in the direction of over estimating the internal resistance value. Less chance of charging at too high of a current when in automatic mode, especially with smaller cells.

The Vapcell compares favorably because it exists. :slight_smile:

You cannot say that, maybe it was calibrated for these IR values.
The test I did in auto mode did look fine enough.

Thanks for the review, HKJ!

I guess there’s no perfect charger, but this seems pretty decent overall.

In auto mode the Internal Resistance is accurate?
Weird that it works that way.

It works the same, the important point is that IR is consistent.

hammerJoe, Henrik didn't say internal resistance measurements were accurate, only consistent. This means the charger will be able to work with automatic charging current selection, at least for as long as its rails are kept clean and in good working order. However, if the rails get play the automatic current selection won't work as good (it'll slow down).

For a charger to feature accurate cell internal resistance measurements it needs rails with direct voltage probing, i.e. a 4-wire setup like testing battery holders, or some other method to bypass the resistance or impedance between the charger's voltage measuring device and the battery terminals. As far as I know, of course.

This is where I understood that it was accurate in Auto mode.

So theres youtube videos that show the charger use different current to charge the batteries, does that mean that theres different versions out there?

As HKJ wrote, the displayed resistance values are about 1/2 of the true, accurate value and are fairly consistent. Poor accuracy, but decent repeatability.

Nothing unusual about that.

So in auto mode what does that mean regarding the proper charging of nimh cells?

In auto mode is uses a table that translates IR to current, because it is consistent it will usually use the same current for a specific cell.
If the table is made with the measured values (Opposite the correct IR values) it will be very reasonable currents it selects. In my tests the selected currents looks reasonable enough, but as any charger that uses IR to select current a new battery will most likely be charged with well above standard charge current.

Thank you very much for HKJ’s test. It’s very hard and takes a lot of time :+1:

A short time ago I won this charger at the GAW of vapcell Dennis.
Loved the look, feel, and handling of it from the first moment.
Happy that an expert has confirmed it is indeed a good charger.

Thanks vapcell Dennis. Thanks Henrik.

PS. I like the beep :+1:

Aside from the beep, it does inform you real-time of the cell’s status in the bay/s by seeing the battery cylinder bar-graph at all times in the screen as loaded, regardless of which Channel is selected for display, while no “full” info, just a full-bar status of any of any loaded bay when cell is full ( or still charging or discharging), INDEPENDENT of selected Ch in the display.

But you only get that information of you press a button. It is not possible to just look at the charger and see the status. A led for each slot or keeping the display on during charge would fix that.

Oh, I know what you mean by that… for the screen goes completely dark when it goes off, perhaps the trade-off of this type of screen display compared to the usual low-contrast LCD yet permanently ON display that is back-lighted when turned-on……it does rely on the beep.

A led for each slot when the screen goes completely off is a nice touch I agree. :beer: