Seems like 89sabers uses an ncr18650bd on their proffie3.9 chassis
Its a few mm shorter than you standard 18650(button top)
I cant seem to find a reliable place to get extras of em
Any recommendations ?
They are just unprotected and therefore shorter.
Just search for unprotected 18650. They should fit. Although, I have to mention that unprotected batteries aren’t recommended. But protected do not fit, so what do you do, eh?
Panasonic NCR18650BD is an unprotected battery by default, which is generally not recommended.
Please use protected batteries.
You coupd get a protected 18500 and devise a spacer.
How can you tell if its “protected”?
Well anything longer it will not fit the chassis
The product description will say.
This are the different batteries i e seen from sabers i e ordered
Which ones safe which one is not?
The grey on the left is the 18650BD
As you can see its a tad shorter
They aren’t unsafe per se… Just unprotected from over current discharge draw, which can occur in saber blades with lots of leds.
However, back to your question - I would think the batteries that are a bit longer (and are still 18650) are protected, but have a new shrink wrap applied.
It’s actually damage from discharging the battery too much that is the biggest danger.
You do that too much and suddenly your battery starts to swell, and that point it’s a fire hazard…
I would hope that if the hilt has been designed for an unprotected battery, that there will be some kind of protection pcb added somewhere else within the hilt, if only to manage the extent of discharging before the battery is shut off and isolated. I guess with removable batteries, hilts could leave charge management to the external charger, but discharging definitely should be actively managed for the reasons the prof mentioned.
Battery protection really is supposed to protect against three problems:
- over charge
- under charge
- over current (in both directions)
All three will damage the battery, which in turn makes it more likely to fail catastrophically at some later date.
As you point out, a battery isn’t going to charge itself, so a hilt that has no charger doesn’t need to worry about over charge. Over current is a possibility if a short occurs, but since we need 15A from our batteries (which is a lot) sometimes you get a short and the over-current protection just doesn’t kick in. This can lead to melted wires and other things, but the battery is fine. WIthout over-current protection, wires will start to glow, things start to melt, and the battery may catch fire if you short things badly enough.
Under-charge is more insidious, because you don’t notice anything. The battery just sits there and quietly degrades. If you’re lucky, the battery just won’t hold a charge afterwards, if you’re unlucky, it explodes and catches fire.
If you still want to use an unprotected battery, it is very much a “on your own risk”, and don’t say we didn’t warn you.
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