Twice the Run Time and Brighter… B90 Upgrade

[js]

Tom,

Interesting. As you suspected, eh? (I was on the phone w/Tom when this happened, actually ). Well, it could be worse. The fact that you CAN use the standard charger at all, even if you have to double charge, is still a pretty cool bonus. Given the change of chemistry, I remember that we were doubting that the stock charger would even terminate charge properly. So I wouldn't say we "failed". Not entirely anyway.

It may be possible to mod the circuitry to have a different time out. I know on the MAX712/713 chips, this is set by tying two pins to certain other pins on the chip, or even leaving one or more of them open. This is obviously not ideal, not a "drop-in" solution, but still. If it were easy to do, we could do a bunch of them at once, and this *probably* wouldn't hurt with standard B90 packs, as the detection would shut off fast charge at the appropriate time--although we would want to test this to make sure.

Anyway, those are my thoughts, FWIW.

[SilverFox]

Hello Jim,

Thanks for your insight. I am not sure I want to get into modifying the stock charger, but it is something to consider.

I ran a test last night. I charged the Prototype pack until the green light came on, then pulled the pack and put it back in again. The run time test gave me 95 minutes which is what we are hoping for from this pack.

I think I need to do a test where I do a single charge and leave the pack to trickle charge for an extended period of time to see if the trickle charge will bring the pack up to full charge. I know that an overnight trickle charge will not do it, but perhaps a couple of days...

Tom

[T-Rex]

My 2 cents:
The initial charge tops out ~72 minutes. That's still 22 minutes above stock. If I get to the battery, I can reset the charger and get another 23 minutes.

Sooo, if I'm lazy, I get a 44% increase. If I spend 30 seconds to reset the charger, I'll get 90% increase over stock. More run time which would cost me 30 seconds. Even better, put the charger on a 4 hr timer and have it cycle on/off.

I'm still in since I don't see the downside.

I agree with Tom. Given the complications that could occur, I don't want to be messing with the charger if another solution is much less painful.

I have run into another obstacle with this project

...

Comments?
Opinions?
Discussion?

Tom

[wptski]

Tom:

Maybe you ought to forget using the original chargers, go to a wallwart the puts out 9VDC at a low millamps and go for a allnighter?

Make that a 6VDC.

[Topper]

Tom, do want me to pull it off on a solid green? Or wait till it blinks then pull it for a second and recharge or does it matter?
Topper

[SilverFox]

Hello Topper,

Keeping in mind that we are using a NiCd charger to charge a NiMh battery pack, I have done some additional testing. This is not the best set up, but it works very well. We are not supposed to charge NiMh packs on a NiCd charger because the NiCd charger will overcharge the NiMh battery pack. This overcharge can cause the NiMh pack to vent if it gets very hot.

Jim and I were surprised that we were able to charge the NiMh pack on the NiCd charger, then I discovered the NiMh/NiCd switch on my charger. We speculated that SureFire had gone to a NiMh charge algorithm to keep from having additional problems with the B90 battery pack. We may have been fooled into this thinking and SureFire may have put a time limit on the bulk charge instead. Since our batteries are higher capacities, we time out before venting. I will have to set up a data logger to see if I can figure out what is going on.

In the meantime, I put a pack on the charger and left it for an additional 12 hours after the blinking green light came on. Just finished a discharge test and got 94 minutes of runtime. The pack peaked at 4.280 volts which gives us around 1.42 volts per cell.

This is an ideal way to charge and will result in a very long cycle life. A rapid bulk charge, followed with a lower rate charge, finally topped off by an extended trickle charge should fully charge the cells as well as balance the pack. The pack may warm up during the initial bulk charge, but it should stay cool during the rest of the charge cycle.

The only caution would be if you only used the light for 5 or 10 minutes, then put it back on the charger to top it off. I have not checked this out, but will do some additional runs to see what happens.

OK Topper, sorry for being so long winded, but back to your question...

1. If you need the light right away and the pack is dead, charge it until the green light comes on and use it.

2. If you have a little extra time, charge the pack up until the green light starts to blink then use it. This should give you around 70+ minutes in an 8NX or 8AX. Your 9AN run time will be lower because it has a higher current draw. I am observing that it is taking around 90 minutes to go from solid green to blinking green.

3. If you need the maximum run time, charge the pack up until the green light turns on, then you have two options. If time is pressing, pull the pack and put it back in. When the green light starts to blink after the second charge the pack should be fully charged. Or you can leave the pack on the charger with the green light blinking for around 12 hours and let it trickle charge to full charge.

Option 3 is the easiest on the battery pack, but takes the most time.

Let us know what works for you.

Tom

[lm4300]

What about those with the Gen 1 chargers. I took the back off mine and saw no switch, and I've never seen it blink green.

What do you recommend? Once the batteries are available, would getting a new charger be the best way to get the most life out of them?

[SilverFox]

Hello Lm4300,

I believe, but have not tested, that the older style SureFire B90 chargers will cook this NiMh pack and cause it to vent. The new style charger (blinking green LED after a solid green LED) is the one you want.

Tom

[Topper]

Hi Tom, I tried pulling it for a few seconds after it turned green placed it back and waited a long time before it started to blink. I noticed it was a little warm but far from hot so I figured it was good. It ran 16 seconds and my main lamp died. It did not blow up just died and I thought "Dang maybe that was not a good idea after all" then after pouting abit and mourning for a costly lamp two things dawned on me.
The 20 lumen lamp did not fail and only the Lord knows how many hours I had on that lamp before I started testing this prototype. I located a spare N90 and got 62 minutes run on the cell. That was much better than other runs with my 9AN I would guesstimate I have around 30 or so runs on this pack and the lamp that died was in the light for maybe 2 years before starting this test so I think it was just coincidence.
Topper

[cnjl3]

My surefire charger is so old that the instructions that came with it said just to charge it about 12 hours and then unplug it (a timer solved that problem) - initially i thought i would just order a new surefire charger but instead i will probably use my MAHA charger or my Triton charger for your new improved NIMH battery pack (90+ mins of lumens!!!! WOW!) - wouldnt a modern charger solve everyones charging problems??? Both of my chargers will handle all Nicad, Nimh & li-ions.
Dont get me wrong i love my surefire light- i just have never been that crazy about the charger that came with it.

[SilverFox]

Hello Topper,

I am sorry to hear that your lamp died, but it sounds like it had a good life...

What kind of run time do you get with the stock B90 pack?

Tom

[SilverFox]

Hello Cnjl3,

The improved battery pack will charge up just fine on any NiMh pack charger. I have been cycling my pack on my Schulze to "break it in."

The reason we are trying to get the pack to work with the SureFire charger is because everyone who has a light that uses the B90 battery pack already has a charger for it. Jim and I wanted to offer an upgrade that did not require anything but a battery change.

If you have a pack charger, I would recommend using it. We are just trying to get it to work with the stock charger so people do not have to go out and buy another charger.

Tom

[cnjl3]

Thanks Tom!

I had already made my own home made "B90" packs i currently
have two of them --but i will probably want at least two of yours.

CYL

[SilverFox]

Update:

The testing continues...

SureFire advertises about 50 minute run time for the 8AX, and the B90 pack should re-charge in about 2 hours. I took a prototype pack and in 2 hours the light had turned green, but was not to blinking green. I did a run time test and got 55 minutes.

So, if you only charge until the green light comes on (about 2 hours), you will still have better run time than the B90 pack.

Tom

[Topper]

Hi Tom,
I have two B90's in use and on a runtime test I got 32 minutes on one and 29 on the other. I tried the "trickle for hours" and got 57 Minutes on the "proto pack". That is real close to 62 minutes on the first try at a reset after turning green. So I think? things are looking good and I will make an attempt at keeping up with the time on this N90 lamp. It has 2 hours on it give or take and I have a second "back up" to this lamp (this was my back up lamp) so I will do what I can as "testing" goes and would prefer this to work out in the long run without me buying another charger
Topper

[SilverFox]

Hello Topper,

Thanks for the information.

It looks like the 9AN will run for around 30 minutes on a stock B90 pack and 50+ minutes on the NiMh pack. With the 8NX and 8AX I am getting around 45+ minutes on the stock B90 pack and around 90+ minutes on the NiMh pack.

I just finished testing a double charge. It took 4 hours to go from red to green, two times. Hot off the charger I got 95 minutes of run time with the 8AX.

I think we can hold off on further testing for now. The pack seems to be doing what we want it to do. I am a little nervous about the double charge, but my pack only got warm, so it might be OK.

I still have not received the 4300 cells. I will do some additional testing once we have those made into packs and then we will be ready to start taking orders...

Tom

[Topper]

Hi Tom, PM sent.
Topper

[js]

Tom,

Good news. Good to hear. As you say, it's ideal in some ways to do the charge to trickle, and then leave it for 12 more hours. Nice and easy on the batteries, that's for sure. In fact, I bet that trickle rate is so low, it would be reasonable to leave the battery in the charger for days and days at a time (but not weeks and weeks). And the single or double charge are both still fine options, really.

I look forward to what happens with the 3 mil ribbon and 4300 cells!

[europium]

I am going to withdraw my offer to purchase 3 battery packs. There have been a number of problems, none of which alone is too substantial, but I feel that this new battery pack solution falls a bit short of my expectations.

I think it is a worthwhile project and I wish you success.

I am left thinking that:

(a) Surefire itself should solve this 'problem' of short runtime by offering a NiMH battery upgrade + a new improved multi-chemistry charger for its stock B90 rechargeable lights,

(b) It is long past time for Surefire to join the 21st century by offering Li-Ion rechargeable lights with both better outputs and longer runtimes than their current rechargeable lights, &

(c) Surefire should also upgrade stock incandescent lamp assemblies to produce better, whiter output with the same expected lifetime so as to compete with 3rd party LA offerings which are not only better but cheaper than what Surefire now sells.

Just my 2 cents.

Eu

[SilverFox]

Hello Eu,

No problem at all.

Developing a new product is not without its pitfalls. I have been very vocal about the process we have been going through so people can make an informed decision.

If I may take a moment and comment on your "thinking..."

(a) SureFire is interested in this project, however there are a few obstacles to overcome. They have a stock pile of NiCd cells, it costs money to re-design a charger, NiCd chemistry is less effected by heat and cold, NiCd chemistry has a lower (but not by much) self discharge rate, NiCd chemistry can tolerate extended times of trickle charge better, lower capacity NiCd cells may be able to handle physical abuse (through dropping and recoil loads) better than higher capacity NiMh cells, the lower capacity NiCd cells have a higher cycle life than the higher capacity NiMh cells, and we have to realize that not every SureFire flashlight owner is using the B90 battery pack.

I am steadily chipping away at all of these obstacles, however I am not sure there is anything I can do to improve the sales of lights that utilize the B90 battery pack. Fortunately there is enough interest to do a limited run, but I don't think there is enough interest for a full blown production run.

(b) I think SureFire should skip Li-Ion completely and move on to the Li-"safe" cells that will not rapidly vent with flames when abused. Li-Ion cells can malfunction when subjected to physical abuse (when dropped or exposed to recoil loads). Unfortunately these safer cells are larger in diameter and I am not sure SureFire is ready to re-design their product line.

(c) I think the design of the SureFire lamps is very good. A problem occurs when the battery pack can not maintain voltage under load. In those conditions, the lamps "whiteness" is diminished. The NiMh replacement pack not only will offer extended run time, but it also holds the voltage better under load resulting in a whiter beam.

Tom

[js]

europium,

Glad you have reached clarity and made a decision even before the final proto-types have been made, let alone the first production run samples.

Impressive! You aren't psychic are you?

[SilverFox]

Update:

The 4300 and 4400 cells have arrived. I will put them through some cycle testing and then send them to be assembled into packs. More prototype testing to follow.

Tom

[lm4300]

A new B90 charger from SF is $67.00!! Where can I get one cheaper?!

[SilverFox]

Hello Lm4300,

I just got one for free... Well not quite as good a deal as it sounds. I was looking for an 8AX. SureFire lists these lights for $140 by themselves. If you want the charger and a couple of B90 battery packs the price goes up to $207.

I was browsing buy sell and trade and found that Oldgrampajack had a complete 8AX package (including charger) for $139.95 including shipping. As you can see, I got the charger for free.

I would contact SureFire and see if they will sell you only the battery holder for the charger. You should not need a new power supply, and the charger is in the battery holder. They don't list that separately, but it doesn't hurt to check with them.

Tom

[Topper]

I tried something "new" so I thought I would post about it. I allowed the proto pack to charge and left it to blink for at least 12 hours then pulled it and left it to sit 72 to 80 hours (trying to see how it holds the charge).
I still got 54 minutes runtime. After talking with Tom and reading his and js's posts on this thread I have been getting 58-62 minutes every time after letting it blink for at least 12 hours.
That looks good to me.
Topper

[SilverFox]

Hello Topper,

That is good news. The prototype pack seems to be holding up well.

A general update:

I have been cycling the 4300 cells for the past few days and they are performing very well. The 3700 cells did not quite give us twice the run time. It was close, but not quite. If the 4300 cells work out, we will definitely have twice the run time.

I have sent the cells off to have them made into prototype packs. We are incorporating the final changes to the design and if everything works out, we will be ready for the first run of packs ready for sale. By then I should have a price worked out as well.

I will be out of town for awhile and will be doing a lot of testing on the prototypes I have. I am interested in how the packs hold up to field conditions. The purpose of this testing is to see how well the packs are constructed. If I drop my light, I want the battery pack to hold together. I will also be checking cooler weather performance.

When this testing is completed, I will check the size of the 4300 pack, make a decision on pricing and go from there.

Stay tuned... we are almost there.

Tom

[Calamityville_Horror]

I would be interested in trying out two of these.

Great project, by the way. If the cells stand up, they will bring my 9AN back to the front of the line-up.

[winny]

I haven't read the entire thread but if there is any sign-up or "post your intrest here", here is mine.

I'm in for one or two packs, given that they will fit the 9AN. If 4300+ mAh is an option at a higher cost, I'm in for that too.

Keep us updated SilverFox!

[cnjl3]

Any news?

[SilverFox]

Update:

We are still testing. The pack I sent to Dano fit in his light, but it seems that our nipple length is a bit long. We are adjusting that on the new prototype packs.

The lamp on the 8X, 8AX, and 8NX has two springs that make contact with the top of the battery pack. If the nipple is long, there is a possibility of bending the + spring, and if it goes sideways, it could short things out. There is an insulating washer that goes over the nipple, but our early prototype packs had a thick washer that sometimes would get stuck in the lamp springs. We are in the process of finding a thinner insulating washer.

The longer + nipple also makes putting the pack in the charger difficult.

The run time and charging tests have been going well. Once I am satisfied with the other "details" we will be good to go.

Tom