Night Lightning Mini-blaast and Batteryspace 14.8v battery problem
My wife has a Night Lightning Mini-blaast, (Triple R2) which I think has a b-flex 1 in there.
She also has lots of nice 14.8v Batteryspace Li-ion battery packs, all waterproofed.
One thing she found at a 24 hour orienteering race last weekend is that the battery just blacks out when it's getting low, no warning. Also she's not getting the battery life I'd expect. She had a spare battery pack so it wasn't a big problem, but a blackout with no warning wouldn't be great on the bike, and it's hard to change batteries in the dark too.
The MiniBlaast definitely has a voltage warning, and I've programmed it for the correct battery type, but I think the in-battery protection is tripping first. Claire at NL thinks it could be the same thing. Eric's out of town for a week or so.
I'm not certain if all the batteries are doing this, as it's hard to test indoors without overheating things, but certainly a couple of the packs have this problem.
She's off to Switzerland for a 4-day adventure race next, so I'd like to see if there's a work-around. Anybody else familiar with this issue? Any ideas?
Last edited by Ofroad'bent; 05-07-2011 at 05:02 AM.
I should mention that I got another Batteryspace pack recently that was nicely set up and plasti-dipped by Scar, which we haven't tested yet.
Heard back from Batteryspace. They think one of the cells is bad in that particular battery, and will fix it for $35 plus cost of new cell and shipping.
Considering the battery cost $55 new, it's about 9 months old and was rarely used and stored properly charged, and shipping was very steep, this battery sure wasn't great value.Barb needs it pretty soon too, as a spare for the race.
It's one of these:
I may just cut it open myself, but I don't have a hobby-type charger that can cycle the batteries so I'd have to replace them all.
What would you guys suggest?
Ofroad'bent - Bummer on the wife's battery. Just want to make sure you know that the battery I did for you is not the "Chinese cell" version.
I have never purchased any of those "Chinese cell" versions so I don't know what they behave like over time. Never thought the savings would be worth the gamble.
Be interesting to see how the battery I did for you performs.
Yes, I was hoping I clarified that. The one you did should be far better- I wish I'd gotten them all from you. I'll try and test it on the weekend, when I can run it for 8 hours or so and keep an eye on it.
Must be a bad Chinese cell in the 4-battery pack. We've been testing Scar's 4-cell pack, and the light's gone almost 17 hours so far on Medium, vs 5 on the bad one. The bad pack was a "good" deal, only $55 all waterproofed with a Trailtech connector. Not so much now. It must have been running on 11.1v, below the NightLightning's warning level.
If I take it apart, is it conceivable that I can find the bad battery and replace it with one of similar capacity to the others, or is the whole pack toast?
I can test voltage, but don't have a hobby charger to deep cycle them.
I'm leaning towards getting a protected 4S1P holder and using the connector from the bad pack with 4 new cells, then using the scavenged cells for smaller projects.
Shoot me a PM and ill fix it for ya . Its really not huge issue for me to fix for ya.
You can likely make it work better by replacing the defective cell, but to really fix it to work the way it should, you would need a cell that's matched to other cells in the pack. That would mean a cell from the same manufacturer with the same specs and similar history in terms of age and # of cycles.
Originally Posted by Ofroad'bent
If you have multiple packs that are having trouble, that are all the same with a similar history, you may be able to take apart all the bad packs and rebuild a few good packs. But it's a lot of work and you really need a battery analyzer to get the best matched cells together.
If you just replace the bad cell with a new cell, the new cell is going to be stronger than the other cells in the pack. That means the pack will not be capacity balanced, which is different than state of charge balanced, and the weaker cells will run down sooner than the new stronger cell. That will fool the normal voltage measurement in the bflex driver and the pack will still cutoff unexpectedly when the pack protection PCB shuts the pack down. It'll run longer than now, but the weaker cells will also be discharged lower than is ideal and the pack won't age very well since the weaker cells will degrade faster.
Thanks, folks. It sounds like I may need to split up the pack and use the batteries with any capacity left to make a smaller pack, and get Barb a new 4-cell one with fresh cells. I'll still talk to Pat at Ballistic and see what they say.
Last edited by Ofroad'bent; 05-08-2011 at 05:58 AM.