Will 18650 driver work with 3AAs?

Hi BLF! Could 3 x 2000mAh eneloops be used with a driver originally designed to be powered by a 18650 li ion cell? I have a cheap 3xAA host and I’d like to replace the driver… I realise every battery has a limit of how much current it can deliver but could 3 eneloops work for a driver with a max output of 3A?

Are there any problems that might crop up? If I had the choice, would a 3 volt low voltage cutoff be appropriate for eneloops, or would a 2.7v cutoff be better? Will fresh eneloops sag below 3v (if that was the low voltage cut-off limit) with a 3A load? What about the upper voltage limit; how high is the eneloops voltage fresh off the charger?

These may be basic questions but I would love any help I can get!

Thanks!

Yes it will work but they may not be able to do as much current. 2.7 low voltage cut off would be best. Eneloops are around 1.45 volts at full charge.

For the common AMC based drivers even 4 Eneloops are fine. Cutoff.. I dont know. I mean, those are Eneloops, you can abuse the hell out of them.

Actually come to think of it you don't need a cut off since the light will turn off when vbatt<vf. That would probably happen around 2.8-2.9 volts so around the .9 volts for each battery.

Yeah it should work fine. I have had my eneloops up to 3.2A without any problems. I try not to discharge mine lower than.8V, but I have had them way lower than that before and they seem to perform just fine.

Thanks guys, sounds great. I wont be pushing it to 3 amps due to heat build-up (probably more like 1.5A) but its nice to know what eneloops are capable of!!

If you mean 18650 driver is 7135s with 3xAA eneloops.

  1. Make less resistance of AA holder, use thick wire and thick -springs .
  2. When you draw 3A each cell is about 1.1-1.2V with no. 1 set up.
  3. Do not use Hi mode for long time
  4. Do not discharge lower than 0.7-0.8V per cell

I’ve had a crash course in 3AA limitations, basically for an xm-l using a nanjg 105c driver (linear regulator) you can expect 0.8-1amp from most NiMH batteries, and 1.8-2amps with Eneloop batteries. I have come to believe this is due to internal resistance and voltage sag under load. Most batteries can do 3 amps without trouble, but it seems the voltage gets too low to drive a xm-l led. I can only assume these conditions would stay the same with any driver except a boost one.
Here is a page that shows voltage, current output and lifetimes. I’m pretty sure that some voltage is also used up by the driver before getting to the led.

Don’t even try more then 500ma with alkalines if you want decent run times at full power.

I dont have any fancy equipment besides some magnets, thick leads and a DMM but I just did a quick test with an XML and 3 partially depleted Eneloops. Voltage without load was 3.84V (3 cells in series) which dropped to 3.4V under load resulting in 2A to the LED. And I remember that when I did the same test with fully charged cells.. 3A wasnt the limit. ;)