Imalent DDT40 review (5180 lm,4xXM-L2+2xXP-L,4x18650)

kreisl

Flashlight Enthusiast
Joined
Jul 5, 2012
Messages
2,214
I bought replacement batteries, GOLD PEAK brand, super cheap omg. Out of the box 12.306V, nice. I've never seen cylindrical Alkaline cells with such high voltage before. Since i was curious about standby current drain, i tried to measure that "leakage current" with my DMM.

More long-term observation/tests, a follow-up. I left my DDT40 in storage for a few months (3+ months), i can't remember though in which 'state/mode'. Well, i hadn't broken the electrical connection/path by untwisting the anodized threads, because i did want to test the standby current drain. Also, iirc i left the system (=flashlight + remote control) in such a way in storage that i could grab the remote control at any time, press one of its buttons and activate the light from a remote location without ever touching the flashlight itself.

DDT40 users know that one can only remote-switch on and off the light, if the flashlight was manually activated before and left in a special standby mode.

So i left the light in this special standby mode on purpose. For those 3+ months. Also because i enjoy operating the light without touching the flashlight itself. Btw, this is actually a bit similar to a TV: only when the TV has been turned on thru the main switch and left on running can you make use of its remote control; if the TV has been turned off thru the main switch, you cannot turn it back on with the remote control. One can only turn the TV back on with the remote control, if the TV is in standby mode and not completely switched off. Master slave configuration.

It was clear that leaving the DDT40 in that special standby mode would drain both the batteries in the flashlight and the Alkaline battery in the remote control. Today i checked:

The 4x generic protected NCR18650B were at 2.858V each :eek: (i had left them fully charged 3+ months ago iirc :thinking:).
And the substitute Alkaline still has 10.329V :clap:. (which i find surprising because the original Alkaline was dead after few months of non-usage) EDIT2: Oct 2016, the substitute Alkaline is unusuable by now, during RC button pressing the online voltage drops below 7.000V and that's where the RC stops working. I am inserting a fresh 12V Alkaline battery, out of the box 12.176V, and will leave the flashlight mechanically locked out during storage!

It is also clear by now that the casing of the remote control is made out of plastic, even though it looks and feels like metal. Once you open the remote control and look inside, you'll see etc.

Conclusions:
1. Maybe the remote control does NOT have serious drain. Looks like that. So maybe the original Alkaline battery was just poor quality stuff. I got the substitute Alkaline in January and it's been in the remote since. That's good news. Hence i am herewith withdrawing my previous claim from Oct'15 that the RC has serious drain. Sorry for the false alarm back then. ( not my fault though imo )
2. I need to redo the NCR18650B drain test, in special standby mode, because i can't recollect correctly whether the batteries were indeed left fully charged in the flashlight. I am pretty sure that they were but i am not 100% sure. My bad lol.

EDIT:
new drain test, starting with fully charged NCR18650GA, DDT40 in special standby mode (light can be activated anytime merely with the remote control!):
2016-07-22 : 4x4.182V (overnight settled and equalized)
2016-07-28 : 4x3.836V omfg!!!

new drain test, starting with fully charged NCR18650B, DDT40 in special standby mode (light can be activated anytime merely with the remote control!):
2016-07-29 : 4x4.184V (overnight settled and equalized)
2016-08-?? : 4x?.???V TBD
 
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kreisl

Flashlight Enthusiast
Joined
Jul 5, 2012
Messages
2,214
EDIT:
new drain test, starting with fully charged NCR18650GA, DDT40 in special standby mode (light can be activated anytime merely with the remote control!):
2016-07-22 : 4x4.182V (overnight settled and equalized)
2016-07-28 : 4x3.836V omfg!!!

new drain test, starting with fully charged NCR18650B, DDT40 in special standby mode (light can be activated anytime merely with the remote control!):
2016-07-29 : 4x4.184V (overnight settled and equalized)
2016-08-?? : 4x?.???V TBD
finished the tests:
2016-08-30 : 4x2.868V (and the light doesn't turn on anymore with the remote! clearly, the light must have reached the 2.868V days/weeks ago already, i am no stupid)

Being very surprised about the 2.868V, today [sic] i decided to just measure the standby current directly. Wasn't that hard tbh by way of the common 'tailcap reading'-method. Here my readings:
4.2V battery = 0.032A
3.9V battery = 0.035A
2.9V battery = 0.047A (this value can be measured indirectly only since at that voltage level the remote wouldn't work, thus the light cannot enter the special standby mode)

Let's do some rough maths to corroborate the 2.868V result:
(0.032+0.047)/2 = 0.0395A = ~39.5mA, average standby current over the drain time of the battery.
NCR18650B delivers max. 3350mAh or 3.35Ah capacity at such a low current, per battery. 4 batteries deliver 4x as much.
(4×3.35Ah) ÷ 0.0395A = 339.24h = 14d3h15min
That's 2 weeks omfg. If the rough maths is close to the truth, then the batteries reached the 2.868V about 2 weeks ago already :hairpull:. For the sake of argument i will repeat the test with 4 fully charged NCR-B's and stop it after 14 days. By that time i would expect the battery voltage to be below 3.0V, i.e. fully depleted. Very uncool.

Btw in the normal standby mode, the drain is ~0.23mA only. It would take 6.5yrs+ to drain 4 NCR-B's at such a low rate!

EDIT:
new drain test, starting with fully charged NCR18650B, DDT40 in special standby mode (light can be activated anytime merely with the remote control!):
2016-08-31 : 4x4.187V (overnight settled and equalized)
2016-09-14 : 4x3.284V OMFG
With this result my previous observations have been re-re-reconfirmed. We're learning: We can leave the light in regular standby mode but not in special standby mode. That's fine with me, i can accept this situation.
 
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