Kaidomain 32600 7.2v packs

[missionaryman]

Has anyone got any experience with these battery packs yet? They are essentially a 2D LiIon 7.2v pack.
I am not sure how to safely use the supplied charger and mine won't fire up the ROP high without an NTC which makes all their wonderful claims of high current constant discharge a pile of crap.

 

[Jauno]

I am not sure how to safely use the supplied charger

I made safe contact with battery + and - sides to charger´s clips with small magnets.

and mine won't fire up the ROP high

Same here

 

[davidt]

I'm pretty bummed out my the battery pack won't fire the Hi ROP bulb. It actually fired the bulb a few times yesterday at 7.6v and 7.7v without too much trouble, but I tried it again this morning with 8.1v and the bulb won't light no matter how many times i try to warm up the bulb with multiple clicks.

Is there anyway I can solve this problem? Missionaryman what is the NTC you mention? Is there any device that can provide a momentary current boost to start the bulb?

I don't know what to do now. It took 28 days for the pack to get here and kaidomain only allows 30 days for a rma request:sigh:. I could RMA the battery and charger back and spend the money to get a pack of elite 1700s. I'm going to be really disappointed because the 1700's will only get a 1/3 runtime of the kaidomain pack.

Supposedly the kaidomain pack can supply 16 amp discharge, does anyone know how many amps are required for Hi rop bulb startup?

I was really stoked about the battery; a full hour of runtime on high. Now it won't even light the bulb no matter what I do.

 

[Northern Lights]

Luici,
The NTC I sent you last year were part of the overall original experiment. After a bunch of test and calculation one is found to perform best to the paramaters of the hot wire. I do not remember whether I got the good ones to you or not; Jim and I use this one;

SL12 1R010

Max Steady State Current Up to 65°C 10.0 A
Resistance @ 100% of Max Current 0.027 oms

Resistance @ 50% of Max Current 0.060 ohms

http://www.ametherm.com/Data%20Sheets/SL12%201R010.pdf
purchased here.
http://www.newark.com/72J6730/passives/product.us0?sku=AMETHERM-SL12-1R010&_requestid=133864
Turns out to be the best for our syle of hot wire.

Anyone wanting information on how these work in mods please search CPF for key word NTC, under posts by Jim Jones or Northern Lights, anything said here would be redundit, they do a good job at soft start overcoming protection circuits and protecting bulbs from insta flash.​

​

 

[monkeyboy]

I guess the incan crowd won't be too pleased if it can't even fire up a ROP-HI. I'm using mine in a quad cree mod. I'm getting almost exactly twice the runtime over 2 x AW C cells which indicates that the capacity is as good as or even better than what was claimed. One slight concern is the pack comes off the charger at 8.48V (4.24V per cell) which is a little on the high side.

 

[Drewfus2101]

Surely the problem can't be that it can't discharge enough current to light the ROP High bulb. I'm lighting that bulb 99% of the time on 2 x 18650 Ultrafire protected batteries.

I've read the max a protected Li-Ion can discharge without tripping the PCB is twice its current, so 5 amps for the ones I have. If that thing can do 16 amps, I don't think that is your problem.

 

[Jay T]

Any chance that AW's soft starter switch would help this thing launch? If not there goes my hopes of using em with the 5761.

 

[Northern Lights]

Any chance that AW's soft starter switch would help this thing launch? If not there goes my hopes of using em with the 5761.

If it will start on the NTC then AW's driver will work. That is what happened when AW brought his C batteries up against the 5761. You had to double and in some cases Bazillion click it to start. Models I made with those cells and the 5761 would start with either the NTC mentioned or the AW driver, both successfully soft start.

The 5761 pulls 5.43 amps so on cold start it is way up there until it heats up, that is in thousandths of a second, however, as that is the reaction time of the NTC. If the PCB trips on 5.43 amps you won' start it.

 

[missionaryman]

The reason that it's not lighting the ROP is because inrush current is about 20AMPS for a few milliseconds which trips the protection. Protection circuits have nothing at all do with battery capacity they are simply working within their design parameters. A soft start is what's needed to cure the problem.

Keith, I tried the NTC's you sent me and they worked - but how much voltage do you drop with the one your mentioning?

 

[Mr Happy]

The reason that it's not lighting the ROP is because inrush current is about 20AMPS for a few milliseconds which trips the protection.

Absolutely. If you have a DMM, measure the resistance of a bulb when cold. You will likely find it in the 50-100 mOhm range (or less even with a fat bulb like the ROP). In other words, when you connect such a bulb to a battery you are applying a dead short across the battery terminals.

Li-ion cells have very necessary protection against dead shorts, so it is no surprise if the bulb won't light under these circumstances. A soft start is essential for reliable operation with such combinations of bulb and battery.

 

[Northern Lights]

The reason that it's not lighting the ROP is because inrush current is about 20AMPS for a few milliseconds which trips the protection. Protection circuits have nothing at all do with battery capacity they are simply working within their design parameters. A soft start is what's needed to cure the problem.

Keith, I tried the NTC's you sent me and they worked - but how much voltage do you drop with the one your mentioning?

I cannot get Lux's photos on the work computer, filtters do not like his host so I cannot get the ROP max amps from his chart; I think I remember @4.5 amps, so I will use that draw as a demo of the formula. Plug in your own numbers, or maybe later I will fix this but I am in the middle of switching over my personal system and have access problems too.
NTC Specs. 1 ohm cold resistance.
Max Steady State Current Up to 65°C 10.0 A
Resistance @ 100% of Max Current 0.027 oms
Resistance @ 50% of Max Current 0.060 ohms

This NTC has 1 ohm resistance cold, so apply Ohms law for Vdelta, Volt drop when cold.
In milliseconds it is hot and drops the reistance to a minimal amount.

After the bulb warms up it is for the purpose of demo here I chose 4.5 A as the bulb drain. The NTC at 5 A is 50% of 10A rating of the part. At 50% or 5 A the NTC is at 0.06 ohms. 5 Amps to 10 amps is 5A spread . The NTC covers 0.027 to 0.060 ohms. The difference is 0.033 over 5 amps or 0.0066 ohms per amp. If the ROP is 4.5 then the residual ohms pulled is 0.06 - [.5 x 0.0066] = 0.0567 ohms still left on the NTC.

Therefore your Vbulb is reduced by the added resistance or 0.0567 or as published 0.060 ohms. Need to know you Vbulb or Amps to calculate the drop in the first place or best just to take the measurement. e.g. the emolis ran the bulb of the 5761 at 6.9 volts but I do not remember what the drop was, duh. The emoli should have been Vb > 7.2. The drop is 0.3 volts,

It checks out with ohms law, Amps x Resistance = Volts, the change in volts. e.g. 5761 is 5.43 amps draw overdiven at @ 6.9 to 7.1 volts. 5.43A x .060 ohms = .3258 Volts

Because of the linear decline is resistance over the short spread of operational specifications it turned out that the NTC, SL12 1R010, had the lowest remaining resistance after start up.

The ones you have That I gave you will have a higher resistance and thus lower operational voltage. Each one has the model number and you can get the spec at the ametherm site.

 

[2xTrinity]

I guess the incan crowd won't be too pleased if it can't even fire up a ROP-HI. I'm using mine in a quad cree mod. I'm getting almost exactly twice the runtime over 2 x AW C cells which indicates that the capacity is as good as or even better than what was claimed. One slight concern is the pack comes off the charger at 8.48V (4.24V per cell) which is a little on the high side.

Mine comes off at ~8.3v, which is pretty much ideal (4.15/cell). The chargers probably have pretty poor tolerance leading to natural variation in voltage cutoff between models.

Aside from that though, the cells themselves seem to be holding up pretty well. I was a bit disappointed that the cells wouldn't light immediately with my ROP-Hi, but the fact that the short circuit protection responds so quickly is, ultimately, a good thing IMO. For one thing, these cells sag less than AW C cells (in tests with ROP low), meaning one would be at greater risk of instaflashing their expensive ROP bulbs without a NTC or soft-starter.

 

[davidt]

Mine comes off at ~8.3v, which is pretty much ideal (4.15/cell). The chargers probably have pretty poor tolerance leading to natural variation in voltage cutoff between models.

Aside from that though, the cells themselves seem to be holding up pretty well. I was a bit disappointed that the cells wouldn't light immediately with my ROP-Hi, but the fact that the short circuit protection responds so quickly is, ultimately, a good thing IMO. For one thing, these cells sag less than AW C cells (in tests with ROP low), meaning one would be at greater risk of instaflashing their expensive ROP bulbs without a NTC or soft-starter.

You got your ROP-Hi to lite up fully charged? How many bajillion clicks did it take?

At least the rop low will have killer runtimes with the battery pack.

 

[2xTrinity]

You got your ROP-Hi to lite up fully charged? How many bajillion clicks did it take?

At least the rop low will have killer runtimes with the battery pack.

By "Immediately" I meant, before adding a NTC resistor in series. Sorry about the confusion. I at first thought I received a dud pack when I loaded it into my ROP, but then when I checked current at the tailcap with my 10A multimeter, it lit up no problem -- the leads added JUST enough resistance to prevent the short circuit protection from tripping, so I was able to discover the reason for the problem.

 

[davidt]

My charger from kaidomain puts out 8.53 volts. Will this over charge my battery pack? I've been removing the battery when they read 8.4 volts.

I'm guessing if I leave the pack on the charger the batteries will reach an end voltage of 8.53 volts. Is this fine for the pack?

 

[missionaryman]

I cannot get Lux's photos on the work computer, filtters do not like his host so I cannot get the ROP max amps from his chart; I think I remember @4.5 amps, so I will use that draw as a demo of the formula. Plug in your own numbers, or maybe later I will fix this but I am in the middle of switching over my personal system and have access problems too.
NTC Specs. 1 ohm cold resistance.
Max Steady State Current Up to 65°C 10.0 A
Resistance @ 100% of Max Current 0.027 oms
Resistance @ 50% of Max Current 0.060 ohms

This NTC has 1 ohm resistance cold, so apply Ohms law for Vdelta, Volt drop when cold.
In milliseconds it is hot and drops the reistance to a minimal amount.

After the bulb warms up it is for the purpose of demo here I chose 4.5 A as the bulb drain. The NTC at 5 A is 50% of 10A rating of the part. At 50% or 5 A the NTC is at 0.06 ohms. 5 Amps to 10 amps is 5A spread . The NTC covers 0.027 to 0.060 ohms. The difference is 0.033 over 5 amps or 0.0066 ohms per amp. If the ROP is 4.5 then the residual ohms pulled is 0.06 - [.5 x 0.0066] = 0.0567 ohms still left on the NTC.

Therefore your Vbulb is reduced by the added resistance or 0.0567 or as published 0.060 ohms. Need to know you Vbulb or Amps to calculate the drop in the first place or best just to take the measurement. e.g. the emolis ran the bulb of the 5761 at 6.9 volts but I do not remember what the drop was, duh. The emoli should have been Vb > 7.2. The drop is 0.3 volts,

It checks out with ohms law, Amps x Resistance = Volts, the change in volts. e.g. 5761 is 5.43 amps draw overdiven at @ 6.9 to 7.1 volts. 5.43A x .060 ohms = .3258 Volts

Because of the linear decline is resistance over the short spread of operational specifications it turned out that the NTC, SL12 1R010, had the lowest remaining resistance after start up.

The ones you have That I gave you will have a higher resistance and thus lower operational voltage. Each one has the model number and you can get the spec at the ametherm site.

Thanks for the reply Keith - so how many volts does the NTC actually take away from the circuit, is it 0.3v?

 

[monkeyboy]

My charger from kaidomain puts out 8.53 volts. Will this over charge my battery pack? I've been removing the battery when they read 8.4 volts.

I'm guessing if I leave the pack on the charger the batteries will reach an end voltage of 8.53 volts. Is this fine for the pack?

For a CC/CV charger (constant current/constant voltage), during the CC stage the charger regulates the voltage to give constant current. After termination, it then switches to CV mode. If you are measuring during the CC stage then this is not the final voltage.

You will get a better idea if you wait for the battery to terminate, remove it from the charger, then measure its voltage.

 

[ptirmal]

Mine comes off at ~8.3v, which is pretty much ideal (4.15/cell). The chargers probably have pretty poor tolerance leading to natural variation in voltage cutoff between models.

Aside from that though, the cells themselves seem to be holding up pretty well. I was a bit disappointed that the cells wouldn't light immediately with my ROP-Hi, but the fact that the short circuit protection responds so quickly is, ultimately, a good thing IMO. For one thing, these cells sag less than AW C cells (in tests with ROP low), meaning one would be at greater risk of instaflashing their expensive ROP bulbs without a NTC or soft-starter.

I don't think there is much of a risk of flashing the ROP bulbs... I run a 2s2p 18650 (5200mah) ROP (most of the time) which has little voltage sag and have never flashed a bulb, and I always pop them in fresh off the charger. The 5761's on the other hand probably have a much better chance of being flashed...

 

[missionaryman]

VICTORY!!!!!

Thank you Keith for the suggestion, I used your SL-12 NTC and it has cured the problem, using Northern Lights' PR to BiPin drop in I measured 8.35v at the bulb pins so voltage reduction is almost nothing.

I now have what might just be the first ever unbored/modified 2D LiIon protected soft start ROP High with over 1 hour's constant run time (if I'm silly enough to let the batteries get that hot).

Thank you Northern Lights.

 

[davidt]

VICTORY!!!!!

Thank you Keith for the suggestion, I used your SL-12 NTC and it has cured the problem, using Northern Lights' PR to BiPin drop in I measured 8.35v at the bulb pins so voltage reduction is almost nothing.

I now have what might just be the first ever unbored/modified 2D LiIon protected soft start ROP High with over 1 hour's constant run time (if I'm silly enough to let the batteries get that hot).

Thank you Northern Lights.

How did you set up the NTCs? Did you use just one or did you run a few in parallel? Where did you place the NTCs?