Kai D-Lithium individual cells

[Chrontius]

Got my ROP parts today, and I'm posting my guinea pig results today, so I hope you don't mind brevity.

ROP-low will happily strike, but ROP-high won't usually light until the second button press. Until I got the hang of it, I got up to 18 or so before I lost count.

90 minutes of calculated runtime is almost worth it, though.

 

[mudman cj]

You're so close. A soft starter would fix your wagon. It would just take the right NTC. Here is a thread on using one.

 

[Chrontius]

Also, the length of the cells is an issue - even with a "golden shorty" low-resistance spring, it's too long, and the thing's probably been permanently deformed. I polished off the sharp edge with a Dremel, but I'm still worried about it eventually damaging the lithium cells' protection board.

 

[2xTrinity]

Also, the length of the cells is an issue - even with a "golden shorty" low-resistance spring, it's too long, and the thing's probably been permanently deformed. I polished off the sharp edge with a Dremel, but I'm still worried about it eventually damaging the lithium cells' protection board.

Yeah, the spring is a bad design out of the box how it "gouges" into the cell. However, if you take that last "winding" of the spring, and bend it down using pliers, it both makes the spring shorter, and makes it so the sharp edge no longer digs into the cell.

There are other steps that can be taken to create more space in the battery compartment. This is the method that I used to fit 2x AW "C" cells in my ROP without requiring an extension:

1) Cut down and/or pre-compress the spring
2) Use a dremel tool to remove as much thickness as possible from the bottom of the switch assembly -- there's at least 6mm of wasted space you can recover.
3) remove the retainer ring holding the switch assembly in place, reinstall the switch a few mm closer to the bezel.

 

[cernobila]

I have tried the Kai individual D Li-Ions in my standard 2x D Maglite and yes had to get rid of two or three of the large coils of the original spring as well as few of the small coils from the other end. The original spring is now much smaller but works perfectly. I have bent the end of the spring in a little so it doesn't scratch the "-" terminal of the battery. I found that the individual Kai D cells work with the WA1111 bulb with one click without any further modifications to the flashlight. (other than the alloy reflector, glass lens and bi-pin adaptor)

 

[SafetyBob]

I really haven't kept up on this, so does this mean the Kai D-cells are to long to fit in a Voltcraft battery holder? Any official published size?

How have they held up since you got them. They sound like the perfect answer to our power problems.

Bob E.

 

[cernobila]

I really haven't kept up on this, so does this mean the Kai D-cells are to long to fit in a Voltcraft battery holder? Any official published size?

How have they held up since you got them. They sound like the perfect answer to our power problems.

Bob E.

Length comparison of two cells;

2x D alkaline's........................121.4 mm
1x D Kai twin-packs (2x D's).....127.2 mm
2x D Kai individual cells............131.1 mm

Sorry, don't know anything about Voltcraft battery holder.

 

[Chrontius]

Dunno how they'll hold up; they came charged to 3.71 volts each so they went straight in with my ROP-hi lamp. Don't want to run that for more than a few minutes at a stretch, as I haven't cooked it yet and the potting compound is known to outgas, resulting in a fogged lens/reflector.

When I get around to running it for a half hour or so on a 6 volt power supply, or baking it in a toaster oven for a half hour, we'll see how these cells hold up. 'Til then, I'm putting up with the godawful startup that can be 2-40 button presses to light, and I'm mostly using my angle-head ROP-low around the house on NiMHs for the time being.

 

[Chrontius]

NEWS FLASH: BAD MOJO HAPPENED.

Was charging these guys, and one of them - left sitting outside the charger on the fireplace mantle - is now reading 1.09 volts.
Giving it the benefit of the doubt, it is going in my ROP for a one-second burn with an open ... err, no, not the battery-bunker in the fireplace.

With an open pool door, just in case something assplodes.

I figure it may be a glitch with the protection circuit, but I dunno. I figure the Mag will buy me the half-second it'll take to chuck the light, if it's really FUBAR. Thoughts?

 

[Chrontius]

No joy on ROP-high, switching to ROP-low.
ROP-low won't light.

1.09v, 3.92v.

Mr. 1.09 is going in the battery bunker tonight until I know what to do with him.

Suggestions?

I'm open to things like "Buy a 2C host and switch to Lighthound's lithium-C cells".

 

[cernobila]

No joy on ROP-high, switching to ROP-low.
ROP-low won't light.

1.09v, 3.92v.

Mr. 1.09 is going in the battery bunker tonight until I know what to do with him.

Suggestions?

I'm open to things like "Buy a 2C host and switch to Lighthound's lithium-C cells".

I have the same situation, the protection circuit kicks in a bit too early with that cell.....I charged my two cells to 4.18 each, put them in my 2x D Maglite and this has worked with the ROP Low and the WA1111 with one click. When I put in a ROP High or the Philips 5761 the light did not work. I checked both cells and found one to be at the 4.18 and the other down to 1.09. I placed the low cell back in the charger and it jumped back to its full charge of 4.18 in about one second. The same pattern happens with the above bulb combinations. The same cell keeps dropping down. I wrote to Jerry from Kai and he has sent me a new cell to replace the one that keeps dropping out. (the cell is on the way) Apparently the individual D cells should work with all the above bulbs/lamps.

 

[davidt]

I have the same situation, the protection circuit kicks in a bit too early with that cell.....I charged my two cells to 4.18 each, put it in my 2x D Maglite and this has worked with the ROP Low and the WA1111 with one click. When I put in a ROP High or the Philips 5761 the light did not work. I checked both cells and found one to be at the 4.18 and the other down to 1.09. I placed the low cell back in the charger and it jumped back to its full charge of 4.18 in about one second. The same pattern happens with the above bulb combinations. The same cell keeps dropping down. I wrote to Jerry from Kai and he has sent me a new cell to replace the one that keeps dropping out. (the cell is on the way) Apparently the individual D cells should work with all the above bulbs/lamps.

Has anyone on these boards gotten the ROP high or 5761 work with these cells. 2-3 strikes is ok, but 18 strikes unsatisfactory. If 18 strikes are needed to light the high current bulbs than I wouldn't consider the cells to to work with the bulbs.

 

[cernobila]

Has anyone on these boards gotten the ROP high or 5761 work with these cells. 2-3 strikes is ok, but 18 strikes unsatisfactory. If 18 strikes are needed to light the high current bulbs than I wouldn't consider the cells to to work with the bulbs.

Once I will get the new cell, I will do the same tests and let you know the outcome.....

 

[jwl]

Read Post #46 for some additional experience with these cells.

 

[Chrontius]

I have the same situation, the protection circuit kicks in a bit too early with that cell.....I charged my two cells to 4.18 each, put them in my 2x D Maglite and this has worked with the ROP Low and the WA1111 with one click. When I put in a ROP High or the Philips 5761 the light did not work. I checked both cells and found one to be at the 4.18 and the other down to 1.09. I placed the low cell back in the charger and it jumped back to its full charge of 4.18 in about one second. The same pattern happens with the above bulb combinations. The same cell keeps dropping down. I wrote to Jerry from Kai and he has sent me a new cell to replace the one that keeps dropping out. (the cell is on the way) Apparently the individual D cells should work with all the above bulbs/lamps.

Thanks, Cernobila - just what I needed to know.

I'm going to try the charger, but if I don't post for a few weeks, the battery exploded in my face.

Edit: now it's 3.92/3.95.

Edit: lights on ROP-low.

Edit: ROP-high doesn't do anything after about 20 clicks.

Edit: Now ROP-low doesn't do anything either.

Edit: what the crap. It fell to 1.09 again.

 

[Chrontius]

post 46 up there isn't quite true - I had ROP-high working on double-click for the longest time, until I charged the batteries. It also ran on single-click for a while too.

 

[cernobila]

Thanks, Cernobila - just what I needed to know.

I'm going to try the charger, but if I don't post for a few weeks, the battery exploded in my face.

Edit: now it's 3.92/3.95.

Edit: lights on ROP-low.

Edit: ROP-high doesn't do anything after about 20 clicks.

Edit: Now ROP-low doesn't do anything either.

Edit: what the crap. It fell to 1.09 again.

You have to reset the protection circuit in the cell by placing it back in the charger just for a sec, once it is reset you will be ok with the lower power bulbs.....have you tried the WA1111 ?

 

[Chrontius]

No, is that bipin or potted? I don't own a bipin adapter.

At this point, I'm half tempted to throw in the towel, request an RMA, and buy a Fivemega adapter with pack charger.

My other alternative is the AW C-LiIon cells.

Thoughts?

 

[cernobila]

No, is that bipin or potted? I don't own a bipin adapter.

At this point, I'm half tempted to throw in the towel, request an RMA, and buy a Fivemega adapter with pack charger.

My other alternative is the AW C-LiIon cells.

Thoughts?

The WA1111 is very popular bi-pin bulb and yes you will need the bi-pin adaptor, I have the "fivemega" ones and they are fine. You can buy both the bulb and the adaptor from fivemega in one go and yes, its worth while to continue with the D's just for the extra run time 5000mAh compared to 3300mAh in the C size. I have used the Philips 5761 in my 2x C set up and its too bright for my use, I kind of like the output of the WA1111 and now have it in both of my lights, the 2x D and the 2x C Maglites. I now use the ROP Low in my custom WE Eagle (2x 18650) and use this inside the house for a more pleasant floody beam.

 

[Chrontius]

So how does the ROP-low compare to WA1111?