Hello everyone! I recently bought some cheap ProWorx 18650 3000 mAh on Ebay for $3 ea taxed and shipped, and wanted to share my thoughts. I bought them instead of similarly priced EBLs.
I performed a capacity test with my Opus BT C3100 v2.2 charger at 1 A, and they measured about 95% of advertised capacity! I took the wrapper of one of the cells, but it was blank. I’m unsure how they’ll perform at higher amps, but since I don’t plan to use them with high powered lights (<2 amps), they’ll work perfectly for me. I plan to check capacity/volt in a few months to see how they hold a charge. Overall, I’m satisfied with the batteries at $3 each. They ship from USA and arrived in about 3 days. And they net more capacity per dollar than something like the Panasonic NCR 18650GA.
Link to Ebay https://www.ebay.com/itm/362699396316
(Looks like there’s a “buy 1, get one 20% off”, which can brings the price down to ~$2 ea. depending on how much you buy)
*Capacity and impedence tested with the Opus BT C3100 v2.2 charger at 1 A.
Average capacity: 2840 mAh (95% advertised)
Average impedance: 122 ohm
Average weight: 48.4 g
Looks like a good deal! Those internal resistance figures seem high though. Higher than a Samsung 26F which would compare similarly. I’d like to see how they perform at 3 naps. Interesti g there’s no markings on the can, but those are easy to remove if printed. They may be unmarked rewraps or just something from the Chinese parts bin.
Try repeating the test at 0.5A “Charge Test” on the Opus BT-C3100.
The BT-C3100 (if unmodified with better ventilation) will heat up, and pause discharging at higher currents, causing higher than normal capacity reading.
The pink wrapper reminds me of (other than Samsung 30Q/35E which also has similar pink wrapper) the JSZH 2600mAh 18650, which are also available quite inexpensively in our country.
I’ve done capacity test of the JSZH 2600mAh 18650 and they test out correctly (2600+ mAh on my SkyRC MC3000 using 0.5A discharge current). I hadn’t done higher discharge current test though of these batteries. They are supposed to be rated at “4C” or 4x2.6A = 10.4Amp.
If these are the same as JSZH 2600mAh 18650s, then they appear to work acceptably good on low-drain devices (like you mentioned, less than 2 Amps drain).
