Streamlight 20237 SL-B9 Protected Li-Ion USB-C Rechargeable Battery, 2-Pack

Great rechargeable battery for Streamlight Vantage II headlamp. Operators say longevity is same as non rechargeable but it always depends on usage, how long and in what capacity. Charges quickly with USB-C charger. Operators say the difference between this and non rechargeable is that this one just stops working when it needs charged. The non rechargeable will dim before its ready to be replaced. Quality seems good like most Streamlight products. Unsure on value, it depends on how many months/years before it won't charge enough to be able to use.

Awesome batteries. They work great and also fit in some red dot optics

I don’t know why I waited so long to order these. I have purchased countless disposable 20237 batteries over the years for my lights. After they are drained I then have to take them to a battery recycling station as throwing these in the trash is not safe. These are awesome and easily recharged. Keep them in all my Streamlight PolyTac flashlights.

Great invention perfect

Great batteries that last almost as long as the disposable CR123’s I’ve been using for a long time. I say that’s a reasonable trade off given the obvious benefit of rechargeable. MAKE SURE YOUR LIGHT/DEVICE IS RATED FOR THE VOLTAGE!! While these are the exact size of a CR123, they are 3.7 volts and “regular” CR123’s are 3.2. I have used these in a couple lights that are NOT rated (per the manufacturer) for the 3.7 and they work “mostly” fine. My MagLite MagTacs run these, but the light will shut off if you run the light continuous for more than about 10-15 seconds. That is fine for me, but maybe not for you. There is not issue with overheating at least, which was my main concern. If you absolutely need the lower voltage, Surefire makes rechargeable CR123’s that are rated at 3.2. Those are the only recognizable “brand name” that I’ve come across of this type. They are not direct usb c chargeable, but have a small physical charger that holds 2 batteries.

The Streamlight SL‑B9 with its 850 mAh rechargeable battery delivers reliable, powerful light—with up to 1,000 lumens and solid Streamlight build quality. Charging is easy thanks to its micro‑USB port, and the battery life is predictable—you’ll get several hours of steady output before needing a recharge. The light feels rock‑solid, fits comfortably in hand, and the tail‑switch layout is intuitive even with gloves on. Where it loses a star is the price. Streamlight’s reputation shows, but so does the premium cost. For the same lumens and rechargeability, other brands offer similar specs at a lower price—often with USB‑C and extra batteries or accessories included. On performance alone, it’s hard to fault—just hard to justify the price tag. If you want a dependable, rugged, rechargeable light and money isn’t the main concern, the SL‑B9 hits the mark. But if you’re budget‑minded, there are capable alternatives that deliver nearly the same results.

This is the future of batteries, my friends. If you cannot recharge your 123 batteries, you are tossing alot of money out the door. I particularly like these batteries for training. I would use disposable 123 batteries for duty usage, but use these for training. The rechargeable batteries will drain in power over time, but disposables will tend to hold their charge better. overall a terrific value and from a company you can trust.

Came pre-charged, work exactly as well as a regular SureFire battery. Will update review IF battery life falls short of expectations.

Pésimo producto. No merece ni una estrella. Compré 4 baterías confiando en la fama de la marca y la publicidad. De las 4, una ¡simplemente no carga ! (ver foto anexa). La duración de las baterías es mínima. Uso una lámpara de mano frecuentemente, la energía de las baterías dura media hora y después se agota totalmente (!). Es increíble que otras baterías de aparente menor calidad sean superiores a streamlight; en el mismo uso duran hasta 3 días. No es un producto barato, pero es malo , pésimo. No lo compren. ¡Quiero mi dinero de vuelta!