It came last week but i got the wrong plug, Xtar was very gracious and sent me a new north america plug which arrived today
So plugged it in, it did nothing for a few seconds then sprang to life. I’m not sure if thats a first startup anomaly or thats normal, i’ll find out
I put 4 batteries at various levels of discharge and it shows percent charge and mAh put in. It has 4 bays, and you switch between them with the center display button. The sound was turned off, and the manual does not say how to turn it on, i checked online, press the record button twice. It also went into record mode, but i find it confusing so i’m not sure if its recording or not (and i don’t get what it records).
The display go into lower brightness mode after a period of not pressing buttons, any button brings it back, i’m not a fan of this feature, it may save some milliwatts but its not worth it IMO.
I also tested the voltage/internal resistance reader, its polarity sensitive (it will show zero if you reverse polarity test). It shows two decimal places of voltage (3.81V for example) and resistance in milliohms, (the battery i checked was 42 milliohm) and the results are repeatable.
I would like a voltage showing on each bay which it does not have, but the percent is actually a nicer touch, if i had to choose between voltage and percent i would not have picked percent till now that i have seen it (edit: After more usage voltage is superior and fungible)
Edit: First battery just finished with a beep which is nice touch, and the buttons beep each time they are pressed, the beep is reminiscent of the EEG machine in a hospital, i found myself pressing the display button every second to recreate a heart monitor sound :innocent:
Edit 2: With two batteries charged one screen has a charged and uncharged battery and so does the other. I think future iterations should be able to automatically put the two still charging batteries status on the same screen, and even have an option to automatically cycle through both screens when 3 or 4 batteries are being charged whether any are fully charged or not
Edit 3: It sticks at 99% for a long time, about 10-15 minutes (guesstimate, i have not timed it)
Edit 4: I forgot to mention that the probes look like they are plated with gold :money_mouth_face:
(Photo credit HKJ)
Edit 5: Freshly charged battery came off at 4.15V. Second and third battery spent about 15 and 30 mins respectively after charge finished but left on charger before reading came off at 4.15 and 4.14V respectively
Edit 6: Cell number 4 also reads 4.15V. I tested this one with the built in voltage check and it says 4.19V. My multi meter was compared to several others a few years back so i do trust it but can’t be 100% sure its accurate
Edit 7: Confirmation that the first few seconds after you plug it in it acts like its dead before suddenly springing to life. I think it should spring to life right away and count up to 100% ready to use
Edit 8: A few thoughts after using it a few times, the internal resistance reading probes are attached by USB, i am very careful to use the correct tester port and not the charger port, what happens if i get it wrong in a hurry one day, will the charger get fried? I’m not going to test this, but i hope it simply does nothing or gives a visual error, hopefully XTAR can answer this.
Why is the supplemental plug for 3S charging, i have nothing that uses this, and what about 2S and 4S batteries?
The charger claims to have a 15C max temp increase, this is a very good feature, though i have no ability to test it, and i hope it has an indicator that it was activated, so the user knows the battery may have a problem (though tricky if more then one battery is being charged, which one(s) caused the temp rise in that case?
Edit 9: I charged some eneloops at 1.24-1.25V and it said they were under 10, when i know they are at about 75. These batteries are only used in my whole house energy monitor that is not designed for NiMH, so i go through this dance, recharge and after 6 weeks it says they are dead at ~1.25V, i recharge with the BC700 and get about 600mAh in, and put back in meter. This time i used the dragon, and 6-8% when inserted which is obviously incorrect, though it knew they were NiMH on the display. They took about 575mAh, which is about right to recharge and came off at 1.49V. The percent meter is not calibrated correctly for either eneloops or NiMH in general or both.
None of this affects its ability to recharge NiMH (which i suspect did correctly terminate), just that the percent meter is unusable for NiMH and should be ignored.
Edit 10: The startup delay is not caused by the charger but by the power supply, if you plug in the supply and give it a few seconds before plugging it into the charger the charger starts immediately. I’m not sure if the temperature regulation works, some old NiMH got almost too hot to hold, but not quite too hot, so either its a coincidence or it was holding them at that temp (which would be higher then the 15C rise they claim).
Edit 11: I have noticed this charger is putting less mAh into NiMH then my Lacrosse BC700, about 5-10% less by my estimation. I don’t have the ability to precisely measure this so i can’t offer any objective evidence, just personal experience from hundreds of battery chargings over the years
Edit 12: The temperature regulation does not work, i have some NiMH AA batteries that are too hot to hold yet the charger is still trying to charge them (3000mAh in so far)
Edit 13: When you charge batteries beyond 9999 mAh it goes back to 000 as seen here
For the technical review of this charger please see HKJ’s thread