Wholesale 18650 Lithium Battery 3.7V 3500mAh Cylindrical Cell for Energy Storage Systems

Someone setting up a solar backup system for off-grid lighting is going to run these in series to get the voltage they need, and the 3500mAh capacity means they can actually run lights for hours without recharging, which is the whole point—sample pricing is around $8.50 each if you're testing a small batch, but once you hit 500 units it drops to about $5.20, and at 2000+ we're looking at roughly $4.40 per cell.

The 3.7V nominal is standard for 18650s, but what I like here is the LiFePO4 chemistry—it's not going to catch fire as easily if something goes wrong, and the cycle life is rated at 2000 cycles at 0.5C charge/discharge, which is actually better than most NMC cells we've tested, though you lose a bit of energy density compared to those.

We usually have stock on these, but confirm lead time if you need more than 5000 units—the supplier can do custom packaing and connectors for bulk orders, but that adds a week or so to delivery, and MOQ for that is 3000 pieces (check with them first).

Charge voltage is 4.2V ± 0.05V, discharge cutoff at 2.5V, and the max continuous discharge is 10.5A—so it's fine for moderate loads like e-bike batteries or power tool packs, but don't try to run high-drain vape mod or a drone motor that pulls 15A, because of that it'll trip teh protection or degrade fast.

It weighs about 45g per cell, dimensions are 18.3mm diameter by 65mm height, and the operating tempearture for discharge goes down to -20°C, so it'll work in a cold garage for a UPS system—but charging below 0°C is a no-go, which is pretty typical for LFP anyway.