Test/Review of Charger Xtar SV2 Rocket

Charger Xtar SV2 Rocket











This Xtar charger can charge NiMH and LiIon batteries, it can handle fairly large cells and can also use a both low and fairly high charge current.







I got the charger in a retail cardboard box from. The box has a lot of specifications printed on the back.







The box contained the charger, a mains power supply, a car adapter a instruction sheet and a warranty card.







The charger has a DC input socket (5.5/2.1mm) where either the power supply or the car adapter can be connected.







The user interface is a display, two leds and one button.

A short press on the button will change charge current between 0.5A, 1A and 2A, a double tap (Why?) will change to 0.25A, a long press will turn the display off. With display off a short press or removing/inserting batteries will turn it on again.

The CH1/CH2 leds are red while charging and green at all other times.







The display shows selected current and how much the batteries are charged. After some time the brightness will be reduced, but it is still easy to read the display and a press on the button will return it to full brightness.







The charger uses the typical slider construction with a metal rail and works smoothly from about 30mm to 71mm, i.e. the charger can handle long protected 18650/26650/32650 cells.

Notice the long metal bar at the plus connection, this makes it possible to handle 32650 and D cells, it also means that flat-tops with very retracted plus pole may need a magnet to connect (The flat-top cells I tested worked directly).

















The charger can handle 71 mm long batteries, including flat top cells.

Many high current 18650 can be charged at 2A with only a minor impact on lifetime.







Measurements

  • When not powered a LiIon will discharge with about 2.3mA.

  • When not powered a NiMH will discharge with about 0.8mA.

  • When LiIon battery is full the charger will charge with 0.6mA.

  • The charger will restart if battery voltage drops below 3.94 volt.

  • Charge will restart charging after power loss, or battery insertion.

  • Charger will charge from zero volt with about 100mA

  • Below 2 volt the charger assumes NiMH

  • Between 2 and 3 volt the charger uses 10% charge current

  • Above 3 volt regular LiIon charging is used.

  • Power consumption when idle is 0.6 Watt (0.9W with bright background light).



Charging LiIon



Nice and fast CC/CV voltage charging with 65mA termination.



It is the same on the other slot.




Other capacities are handled just as fine.



Also the old cell is handled as fast as possible, but due to the higher resistance it will spend more time in CV phase.



Again a good CC/CV curve and the termination current is lower at 35mA.



Also a good charge curve.



The charger easily handles two cells at 1A.



At 2A the temperature raises, but the charge curve is the same nice one.



M1: 45,3°C, M2: 45,8°C, M3: 48,0°C, HS1: 62,9°C
At 2A the charger is warm.



The charger needs 2 to 4 seconds to start, as can be seen the current slowly ramps up.



This is also the case when changing current, when increasing current it is ramped up, when reducing current drops immediately.



Charging NiMH



The charger start charging NiMH with a low current, then after about 10 minutes it goes to the selected charge current. Termination looks to be on voltage in this case here, followed by a two hour top-off/trickle charge at 50mA (Charger displays done).



It is the same on the other channel.





The 3 high capacity cells are also handled fine, two of them with -dv/dt termination.



I use a lower current here, this also means the top-off charge is done with slightly lower current.



With a 0.25A current there is no -dv/dt signal to termination on and it looks like the charger terminates on time.
This is not a fault with the charger, but use of wrong charge parameters for the cell.



The charger takes some time to detect a full cell, first the 10 minutes with slow charging and then a few minutes with full current.
It do also use the top-off/trickle in this case.



Two cells at 1A is no problem.



Neither is two cells at 2A, but things are starting getting warm.



M1: 46,7°C, M2: 46,7°C, M3: 46,1°C, M4: 57,6°C,HS1: 63,2°C



The charger needs about 4 seconds, before it starts a low current charge.



10 minutes later it will switch to full current.



With NiMH the current do not ramp, but jumps directly to selected value.



The top-off/trickle charge is done with current pulses at the selected charge current. The pulse is 1 second wide each 21 second. This gives 47mA at 1A charge current.



Charging LiIon and NiMH at the same time

It is possible to charge one LiIon and one NiMH battery in the charger at the same time.
As usual the temperature sensor is on the opposite cell.



In this curve I recorded the NiMH battery, it looks the same as above.



The LiIon also looks the same as above.

Testing the mains transformer with 2500 volt and 5000 volt between mains and low volt side, did not show any safety problems.



Conclusion

This charger can handle from 10440 cells to 32650 cells or AAAA to D cells, the only requirement is that the user selects the correct charge current. The display is rather simple with only current and charge percent.

For a “simple” charger this is a very good charger for both LiIon and NiMH.



Notes

The charger was supplied by Gearbest for a review.

Here is an explanation on how I did the above charge curves: How do I test a charger
Read more about how I test USB power supplies/charger

Looks like all other Xtar chargers Ive tested… always with proper voltage termination across both charging stations and with little variance between them. 2A x 2 and the ability to charge 32650’s is a real plus. I hope these guys can come up with a charger/analyser at some point in the future (and one that actually works properly).

Xtar makes great chargers. I’d pass on this one though because of the lack of a voltage display like the VP1 and VP2’s I own. Otherwise, it’s a charger that does plenty, and does them well.

Edit: I ordered one because it does 2 amps. Yeah yeah, I said I wouldn’t, but I did. Let the flames begin

Many thanks for the test!

If Xtar can change the % into voltage it would be perfect. 2A charging is a nice reason to replace my VP2.

A real rocket great review.

Wish I’d got this instead of a VC4

Thanks for excellent review. Now ordered with confidence.
I hope it will run cooler at 1A than VP2.

Excellent review. Thank you.

At BLF we often hear “you can never have to many flashlights”. But about chargers I am pretty sure there is no vacancy at this moment. If at a given time one of my XTAR chargers chooses to persue a new career at the happy flashlight hunting grounds, I think that I know who will be the new kid on the block.

Has anyone purchased this product and used it for sometime yet? How so you like it? Its got my interest, xstar seems to make good quality products and some of the best termination currents for li ion I’ve seen. A lot of chargers terminate kind of high. Wish there new dragon charger wasn’t $100 there out of their minds.

I’m considering this one or the lotto 500 to add to my collection of vc2 and liito 100 chargers. The input on the vc2 is fairly accurate with cell capacity. Would be nice to run a discharge occasionally. Maybe get a single or double bay analyzinf charger for my yearly recycling. Might end up getting both chargers. The vc2 input has shown me cells that have worn out and gone to recycling but have to run them down first to tell.

Any experience with this charger is appreciated 2 amp charging is nice in a pinch for time or my 26650.

Thank you for the review.

I have two XTAR SP2 chargers which seem to be a previous version without any readout or a .25 amp charge option. I use this charger often, but see little advantage to change this newer one.

I have several Xtar chargers. I have to say I’m extremely pleased with all of them. Just ordered one of these to charge my 26650’s at 2 amps, and charge my Eneloops as well. The only thing I wish it had was a voltage readout instead of percentage.

I agree, I like Xtar also…. but I sure do agree with what you say about the voltage readout instead of percentage. :+1:

I agree with your agreement :slight_smile:

:partying_face: I love it………. :+1: … :wink:

I’m leaning towards this one or the efest 4 luc.since it has 2 bays at 2 amps or 4 bays at 1amp. But I know of xstar quality. My vc2 would be considered commercial use and still going strong. By commercial I mean it never gets a break 24/7. I have a line of cells always ready to get recharged. The only one amp charger I have is the litto 100. .5 amp charging even in 2 bays isn’t really cutting it anymore. 1 amp would work. It would nearly cut time in half.

What I was thinking with this charger is you could start the charge at 2 amps, around 80-85% scale it back to .5 amp or 1 amp to finish out without to much strain on the batteries. To many choices. I do need a rapid charger just not for my sets of 26650s. But for during hurricanes and such. When the power goes out for days and have 6+ flashlights/lanterns/powerbanks. I need to be able to rapid charge my cells even if it is just to 80% to keep cells in rotation fast enough. Even with 30 cells .5amp won’t cut it. With my power inverter and usb ports I can hook up 3-4 chargers in the vehichle as needed

+1

I agree with both of you. :slight_smile:

It might be a good opportunity to purchase at a reduced price the older XTAR SP2 which seems to be a similar but without readout screen and lower amp charging choice of .25 amp.

I have 2 SP1’s that do 2 amps. But they don’t do .25 amps nor NiMH’s, and doesn’t have a display. Even though it doesn’t have a voltage readout, it still gives you enough information about where you’re at in the charge cycle. I’ll probably give one of my SP1’s to a friend.

BTW, I ordered mine from Xtar Direct for $32 delivered. I bought my VP2’s from them and I’m satisfied with their quick USA shipping.

+1

Amen!!! :wink:
Ya’ know, that is a great idea about the XTAR SP2 ‘sidecross’. :+1: I have one, it charges at 0.5A, 1.0A & 2.0A and you are correct… it does not have “the screen” or the 0.25A charge. (To me both of those features are worthless anyway.)

I found the XTAR SP2 at this place at what appears to be a good price. Plus these guys are great to deal with…. shipping is almost immediate.

+1

That is a very good price for an excellent charger. :slight_smile: