Imalent DT70 battery contact problem

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kwarwick
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Imalent DT70 battery contact problem

Has anyone else encountered a problem with the “springs” they use for the negative battery contacts? I noticed with mine that a couple of the cells were sitting slightly lower in the carrier and there was basically no spring action behind those cells.

After doing a few tests I found that one battery was not being discharged at all so must not have been making proper contact. It was not very easy, but I was able to bend the negative contacts a bit to get them to actually act like springs and was able to get all 4 batteries discharging evenly.

The springs in general seem pretty weak in this light considering the high currents involved, so I don’t have much hope that my rehabilitation will last long. Unfortunately the negative battery plate looks to be glued in so fixing this properly with better quality springs would be very difficult I think.

Edited by: kwarwick on 03/14/2017 - 18:20
Lexel
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You could add brass buttons on to of the springs and maybe add bypass as well

g_sintornillos
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Sorry for my bad English

kwarwick
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Because the negative contacts are on a plate that appears to have been installed from the top and glued in place its extremely hard to get in there with tools to affect a solution. If they had used a screw on back cover like the Meteor then this would be trivial to fix.

skywarner
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I registered with this forum so I could share my experience with the DT70 and possible battery contact problems. My DT70 arrived and appeared to be DOA. I tried 2 different USB wallwarts, and no luck. I read up on what others are saying about the negative contacts on the bottom of hte battery holder. So I thought that maybe my batteries were not high enough to make all the needed contacts. I dropped pennies down the battery holders, and they are just the right size to sit on top of the negative contacts.

BUT, this morning I took the pennies back out and I tried one more wallwart … a Samsung. And it worked. Finally I was getting the proper charging indication on the OLED.

So, for me, the moral of the story is, try all kinds of different chargers if your DT70 does not seem to charge. All I was getting was a flashing “IMALENT” on the OLED, meaning it was not charging. But with the charger for a Samsung S5, all was well and I was getting the proper charging progress indication on the OLED.

And, if you really really think that your negative contacts have flattened out too much, drop pennies in there, they are just hte right size.

dchomak
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I am thinking that there is bound to be problems with the springs in this light.
2 reasons, massive current draws from each cell and the fact that each cell is in parallel. If any one spring has a contact issue, the other 3 will have to take up the slack leading to a domino effect, until all 4 over heat etc.

kwarwick
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dchomak wrote:
I am thinking that there is bound to be problems with the springs in this light. 2 reasons, massive current draws from each cell and the fact that each cell is in parallel. If any one spring has a contact issue, the other 3 will have to take up the slack leading to a domino effect, until all 4 over heat etc.

Yes, totally agree with your assessment. This is why I think it is really important to occasionally check the voltage of each cell after some use to make sure the load is being carried evenly by all 4 cells.

hIKARInoob
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kwarwick wrote:
dchomak wrote:
I am thinking that there is bound to be problems with the springs in this light. 2 reasons, massive current draws from each cell and the fact that each cell is in parallel. If any one spring has a contact issue, the other 3 will have to take up the slack leading to a domino effect, until all 4 over heat etc.

Yes, totally agree with your assessment. This is why I think it is really important to occasionally check the voltage of each cell after some use to make sure the load is being carried evenly by all 4 cells.

One of the reasons I like the VP4 charger with voltage display for each bay.

DayLighter
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Actually all DT70 and DT35 also have the same problem with one battery not making contact.. at least they’re consistent Facepalm

The only way to do a great work is to love what you do.

JasonWW
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The DT70 and DT35 don’t use tall coil springs that can compress 8mm or so like other lights use. In order to get more current (and maybe force users to use only their batteries) Imalent used flat disc springs. I think they only compress 1mm or 2mm. This means any non stock batteries have to be just the right length in order to make sure all 4 make good contact.

If shorter than stock batteries are to be used, maybe the stock springs can be swapped with clover dome type springs. You could take 2 per battery and stack big end to big end to get more compression legnth.

My Convoy L6 thread with Texas Avenger FET driver, Narsil ramping firmware, lighted side switch and cut down SMO reflector. Lots of amp draws on stock driver as well.

http://budgetlightforum.com/node/54477

JasonWW
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Has anyone pulled out one of the disc springs? How are they held in place?

From pictures, the bottom of the battery tubes look anodized and the outer edges are bare metal. If so, then maybe swapping to a single clover dome is the best option. 3 would also work if you use shorter batteries, but not an even number. Only odd numbers so you get good contact.

Has anyone ever checked their battery heights? It’s possible the 4 imalent batteries are not perfectly matched. If one is a tiny bit shorter it may not make good contact.

I would measure the batteries and if need be, do a solder blob on the shorter ones and then file it down so you have perfect height on all 4 batteries.

My Convoy L6 thread with Texas Avenger FET driver, Narsil ramping firmware, lighted side switch and cut down SMO reflector. Lots of amp draws on stock driver as well.

http://budgetlightforum.com/node/54477

Tom_182
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I don’t own an Imalent but would it be possible to solder a normal coil spring to the disc spring? Don’t know if the included cells will still fit but unprotected batteries should work this way I think.

Just my two cents. Wink

JasonWW
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Tom_182 wrote:
I don’t own an Imalent but would it be possible to solder a normal coil spring to the disc spring? Don’t know if the included cells will still fit but unprotected batteries should work this way I think.

Just my two cents. Wink


Solder? No. If your using short enough batteries you could drop the springs in place, big end on bottom. The problem you might get with coil springs is they might deform due to the resistance in them.

My Convoy L6 thread with Texas Avenger FET driver, Narsil ramping firmware, lighted side switch and cut down SMO reflector. Lots of amp draws on stock driver as well.

http://budgetlightforum.com/node/54477

g_sintornillos
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I measured the batteries with analog gauge, all are 68.9mm.

For me the “springs” are welded to a plate and the plate is

kwarwick wrote:
had used a screw on back cover like the Meteor

If I measure the length of the interior there is 69.3mm but if we measure it outside we have 76.9mm. The difference is 7.6mm (0.30”).

Now, I measured the batteries in place, avoiding compressing “springs”, …

  1. 78.9mm
  2. 78.2mm
  3. 79.2mm
  4. 78.7mm

In the #2, I think… “We’ve had a MAIN BP BUS undervolt.”

Sorry for my bad English

JasonWW
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g_sintornillos wrote:
I measured the batteries with analog gauge, all are 68.9mm.

For me the “springs” are welded to a plate and the plate is

kwarwick wrote:
had used a screw on back cover like the Meteor

If I measure the length of the interior there is 69.3mm but if we measure it outside we have 76.9mm. The difference is 7.6mm (0.30”).

Now, I measured the batteries in place, avoiding compressing “springs”, …

  1. 78.9mm
  2. 78.2mm
  3. 79.2mm
  4. 78.7mm

In the #2, I think… “We’ve had a MAIN BP BUS undervolt.”


Okay, so it seems some of the springs have flattened or else they were not sitting flat when they were welded to the bottom.

So the disc springs are not pressed in place? They are welded or soldered in?

Can they be pulled out with pliers?

If anyone can supply some good photos, I would appreciate it.

My Convoy L6 thread with Texas Avenger FET driver, Narsil ramping firmware, lighted side switch and cut down SMO reflector. Lots of amp draws on stock driver as well.

http://budgetlightforum.com/node/54477

g_sintornillos
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JasonWW wrote:

Okay, so it seems some of the springs have flattened or else they were not sitting flat when they were welded to the bottom.

So the disc springs are not pressed in place? They are welded or soldered in?

Can they be pulled out with pliers?

If anyone can supply some good photos, I would appreciate it.


They are welded/soldered (I do not know the differences… sorry,“gooelg” translator, in Spanish: soldados) with tin in the same way as an SMD component.

I think the tank of the batteries is separated into two parts and the plate comes out from behind.

Later… fotos, but I do not know if they will be good.

Sorry for my bad English

g_sintornillos
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I insist:

g_sintornillos wrote:
I think the tank of the batteries is separated into two parts and the plate comes out from behind.

Click on images to enlarge.

Sorry for my bad English

Tom_182
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Thanks for the pictures. Maybe the tailcap is glued and screwed in. Somehow the disc springs have to come into this position during production.
Did someone who has this light tried to unscrew the tailcap with a little more force?!

JasonWW
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Wow, what a mess. It’s hard to tell, but they must be soldered in place. They don’t look very strong, but I guess they are more durable than coil springs.

To keep using the stock batteries, it looks like you would need to number the battery holes and then use a metal tool (like dental scraper) to pull up on the 2 ears that touch the battery until they are all the same height. Then after using the light, check the battery voltage and battery heights to see if the ears are staying in place or bending down too far.

As long as all 4 discharge at the same rate, then your good, but if one battery has higher voltage, then it might not be getting good contact. Keep notes because it may be the same disc spring getting flat and not springing back up.

If you have a heat gun you can heat the rear tail cap around the threads then turn it with a rubber strap wrench. That might get it loose.

If the tail cap can be unscrewed then you could solder in a set of double springs or one set with wire bypasses. You may be forced to buy new, shorter batteries though.

Has anyone told Imalent that the little spring ears are bending down and not springing back up and it’s causing uneven battery drain? I’d be curious to hear what they say.

My Convoy L6 thread with Texas Avenger FET driver, Narsil ramping firmware, lighted side switch and cut down SMO reflector. Lots of amp draws on stock driver as well.

http://budgetlightforum.com/node/54477

JasonWW
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It’s also possible that due to the higher spring pressure of the disc springs and the design in general, that you need to tighten the battery tube tighter than the average light to get all 4 batteries making good contact.

Do the instructions say how tight to turn the battery tube?

My Convoy L6 thread with Texas Avenger FET driver, Narsil ramping firmware, lighted side switch and cut down SMO reflector. Lots of amp draws on stock driver as well.

http://budgetlightforum.com/node/54477

atbglenn
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My question is why does Imalent have more problems with their products than most other flashlight companies? My experience with them hasn’t been good.

hIKARInoob
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atbglenn wrote:
My question is why does Imalent have more problems with their products than most other flashlight companies? My experience with them hasn’t been good.

Very little testing and puzzling what works and what doesn’t? Produce as fast as possible to reduce cost?

Edit:

Some time ago there were rumors about a 16000 lumen Noctigon powered by 8×18650 cells. Hank Wang said that hopefully it will see daylight before Christmas 2016. A couple of months ago he mentioned that the design was more difficult than anticipated, so there is going to be a delay. I haven’t read anything about it since then… Basically a good design needs time, and time is money.

JasonWW
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atbglenn wrote:
My question is why does Imalent have more problems with their products than most other flashlight companies? My experience with them hasn’t been good.

I think they try to be fancy to stand out from the crowd and somehow get the basics wrong.

They have design flaws all over. The 4 new lights are said to have very hard to find buttons in the dark, the drivers are flaky and the DT series have these disc springs. Maybe they rush things to market. Maybe they test a little and know the faults, but think it costs too much to fix it, so just sell it like it is.

Some of this could be forgiven if the company took care of their customers, but they dont. They try to ignore them. That’s the worst part.

I wanted a DN70 real bad, but it’s a crap shoot if I’ll get a good one or a bad one. If the good one goes out later, I’m still screwed. I just don’t buy from Imalent. Luckily there are lots of flashlight companies.

My Convoy L6 thread with Texas Avenger FET driver, Narsil ramping firmware, lighted side switch and cut down SMO reflector. Lots of amp draws on stock driver as well.

http://budgetlightforum.com/node/54477

100eyes
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I was considering a DT70, but looks like I should wait for the bigger brand names.

hIKARInoob
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100eyes wrote:
I was considering a DT70, but looks like I should wait for the bigger brand names.

How about Acebeam X45?

100eyes
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I personally haven’t had one of their lights yet; thought about the K70 a while back but saw some reports/videos of smoke building up inside the head.

Mitko
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Imalent- young company, good products, rushing on the marker: voila, there we go, many minor( sometimes major) mistakes.
Exacly like Manker – its only Manker products arent even inovative, yet Imalent`s are

hIKARInoob
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Mitko wrote:
Imalent- young company, good products, rushing on the marker: voila, there we go, many minor( sometimes major) mistakes. Exacly like Manker – its only Manker products arent even inovative, yet Imalent`s are

Really makes me want to Frankenstein a bunch of companies into one…

atbglenn
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Mitko wrote:
Imalent- young company, good products, rushing on the marker: voila, there we go, many minor( sometimes major) mistakes. Exacly like Manker – its only Manker products arent even inovative, yet Imalent`s are

Got screwed once with Imalent. Never again. Never owned a Manker.

Terry White
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One of my DN35'S had the same issue. Even though it is a 26650 cell, the spring needed just maybe to be 1mm taller. 

I took my spring out. Set of needle nose pliers and it popped right out. It was held in place by nothing but it's own diameter. No glue or solder. Really hard to press back in but I got it done

 

What worked on just that light was screwing the head on as tight as I possibly could by hand. No problems after that. 

Not sure that will help here. DN35'S  and 70's oy have a single 26650 cell. You have 4 18650's so it could make the other 3 fit too tight.

I sent all of my video and information to Imalent. I was thanked, and told they would look into it.

Wish I could help more. 

Terry White

nodoubt
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imalent, what junk..
hear nothing but bad reports on these
and NO customer support
they should be sued and shut down

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