Haikelite MT03 over discharging batteries

That problem there can only be caused in the battery tube or you may have used mismatched cells.
I use a set of four new VTC5 in mine (well, when it was still working :smiley: :smiley: ) which i will only use together in the MT03.
I just had a look and they’re all 3.61 Volts

I agree. Has the standby current been measured?

33 µA on my 2S2P early batch one.

edit: I take that back, now I get 665 µA… I’ll have to do some more checking.

So, this is disconcerting, with only two cells, I get the 665 µA but with all four I get 62 mA.

Sorry, was away for a bit. My MT03 is one that Haikelite sent me new 2S2P plates and driver to replace my 4S about a month ago. I resoldered these in and I am not at all sure whether it is now V1 or V2 and I am not taking it apart again! Nor do I want to put cells back it it as I don’t trust mine anymore.

This is not very much. It’s hard to believe it would account for the complete discharge of the cells in less than a year.

Edit: OK he remeasured and got 665 microamps. This current would deplete 1000mAh in 60 days.

So here’s the photos from my measurement from one pair of batteries and with the other one connected too.

I find this strange, since I got the 33 µA back when I did the review.

That’s crazy…
How can the parasitic drain be so much more with 2P ??

Maybe an EE/driver expert could chime in. And no, the light wasn’t lit during either of the measurements :slight_smile:

I’ll leave the cells in for couple of days to see if they’re drained.

I’m really baffled now. Since all of my meters gave conflicting numbers, I tried a clamp. It reported ~22 mA with all the batteries connected. So a week should be enough to drain 3500 mAh batteries.

I will try and charge these cells if they rest at higher voltage and measure standby drain.

Tested just in case with an Agilent 34401A bench meter and it reports 666 µA with 1P and 44 µA with 2P.

I dont trust clamp when measure low current
How about using normal multimeter

666, LOL. I’m so scare
666uA is quite high

And just in case I measured between the battery carrier and head with all the batteries and got 667 µA. Same result for only two batteries in series. Also used button tops to make sure all the batteries have good contact. I suppose this would be the best guess of the true drain so far.

…and i assume the newer version has the same driver… :frowning:

Yea i dont see why they would have changed the driver? It was the 4S that was having the issues?

Parasitic drain is the very reason I prefer mechanical switches over electronic switches!
(although I have a few side switches, they are only welcome if they can be locked out)

I hope there will be an updated version of that driver somehow, because this ain`t good!

Yeah, you’re right, and i remember seeing a picture of the driver in a topic of yours, and it’s the same as mine…

Such a shame they didn’t have us on BLF test the preliminary product before putting it on the market… (although they kind of did use you first buyers as Guinee pigs, in a way…)
The driver basically sucks, but it’s retained by a fat nickel plated pure copper ring (?!) and the ring on top of the battery tube also.
The springs look silver plated.
…but then the MCPCB shelf is less than 2mm thick ?!
Strange things…
It does look awesome though. :+1:

But as said:
Someone who understands this driver could be helpful, maybe have a solution for this high parasitic drain phenomenon.

You can lock out the HT03 by unscrewing the battery tube half a turn.
Works very well, kind of seems to be designed to do so, with the big contact discs.

Had the MT03 sit on the shelf with the fully charged batteries (18650GA) inside for 8 days (188 hours). Charged the batteries and they received 201 mAh in total (52+54+50+45 mAh). So on average 201 mAh / 188 h = 1.07 mA which would equal completely discharging the batteries in 1.5 years. So it is not totally negligible even when subtracting the small battery self discharge or the small difference in charge-discharge capacity. But not quite there with OP’s drain (empty in 6 months). The standby current may of course increase when the voltage drops.