Review: Fasttech 1-4.2 volt single mode driver.

Flashlight Modding and DIY Parts
1

Mode

Battery Current Draw Amps

LED Amps

LED Voltage

Sanyo 18650 at 4 volts

High

1.75

1.45

3.05

Ultracell LiFEPo4 at 3.5 volts

High

1.27

.91

2.94

Eneloop LSD AA at 1.4 volts

High

1.7

.23

2.74

This driver was purchased from Fasttech. Link below.

https://www.fasttech.com/products/1143101

Specifications from Fasttech website.

Specifications

PERIPHERAL TYPE Flashlight Driver

Electronic Components

CONSTANT CURRENT No

DRIVER TYPE Boost driver

INPUT VOLTAGE 1-4.2 -volt

OUTPUT CURRENT 1000 mA

PCB HEIGHT (W/O COMPONENTS) 1.8 mm

REVERSE POLARITY PROTECTION No

Flashlights

MODE COUNT 1

Package

PACKAGE TYPE OEM

Dimensions us | metric

DEPTH 8 mm

HEIGHT 17 mm

WIDTH 170 mm

DIAMETER 17 mm

PRODUCT WEIGHT 2.0 g

Product Numbers

FASTTECH SKU 1143101

Details:

Manufacturer rated maximum currents:

With alkaline batteries: 1000mA

With 1*Ni-MH: 1.8A

With 2*Ni-MH: 3.9A

Again the Holy Grail off multi voltage capable drivers continues. This driver is single mode only and is fortunately not inflicted with the dreaded next mode memory. The driver does indeed operate over the advertised voltage range. Tested output on 3.5 to 4 volts was surprisingly good with led current draw off .91 to 1.45 amps. I’m not sure on the efficiency off the driver. l’ll leave that for the experts. The disappointment was the output on a single AA NiMH. Three different batteries were tried with the testing on each battery performed three times as I expected the output to be higher at the led. The AA batteries used, all fully charged, were a brand new Eneloop, Turnigy LSD and an old Powercell from Jaycar. The Eneloop gave very slightly higher readings.

An XM-L LED was used for this testing.

Other drivers tested for comparison are,

https://budgetlightforum.com/t/-/11523#node-13488

https://budgetlightforum.com/t/-/13350#node-15649

https://budgetlightforum.com/t/-/13427#node-15739

2

now that’s a shame, I wonder why its so difficult to make a low voltage buck/boost circuit give out 1 - 1.5a?

3

I see nothing good. Batery current can not be more than LED current at 3.5-4V. Your measurements must be wrong. The driver is probably direct drive at 3.5-4V.

4

Thanks a lot for sharing!

Output on 1xNiMH is indeed disappointing. Did you try 2xNiMH by any chance?

5

battery current has to be more than led current, thats what’s called losses, you cant have higher emitter current than cell current single cell, you’d need more voltage to convert into current for that ie two 4.2v cells in series.

6

No. I went from the single AA the the LiPO4 which was 1.4 volts to 3.5

I’m sorry Vieplis. I’m not sure what you are saying. If there is something wrong I’m quite happy to amend it. The last thing I want to do is mislead anyone.

7

To be honest, I see nothing good about this driver either. I just bought this from Fasttech.

https://www.fasttech.com/products/1127402

It pulls 1.5A from an 18650. 1.6A from 2 AA and I if I remember correctly 2.2A from a single AA.

I suspect it puts a little more than 800ma to the LED, maybe an amp. I love it and less than half the price.

Marc.

8

The one I have that draws 0.6 A from 2xNiMH must be defective then, or these drivers have a lot of variance...

9

I have used these as well but haven’t done any testing on them due to them be advertised with maximum voltage of 3.6. I will have to explore these a little more. Thanks.

10

Imagine a 0.6 ohm resistor instead of the driver. (4-3.05)/0.6=1.58A, both battery and LED current. (3.5-2.94)/0.6=0.93A. Certainly not worse than your driver.
If you use two amp meters, try to swap them (at 4V).
1.4V is another thing (I guess the driver is not as bad as your numbers).

11

Thanks MRsDNF. I ordered two of these. I don’t know what I’ll do with them yet, but they look like something I should have in my modding box. It looks like it might be a good driver for a Nichia.

12

Maybe you will have better luck than me. I’ll probably use this some where but like you not sure where. The modding box sounds good. :slight_smile: l’ll Have to do some destruction testing on the driver marcl refered to. I’ve been using them for awhile but never thought to try them at the higher voltage.

13

Yeah, that’s very low, mine is drawing way more than that. It pulls the same as my Klarus P2A at the tail and the output (to my eyes) is about identical. Needless to say I am very impressed with it.

Marc.

14

OK, mine (with 2AA / XP-G2) is definitely weaker than my P2A.

The thing is, I had ordered two of these drivers, and the other one pulls about 2 amps from 2 eneloops (albeit with an XR-E). Yours seems to be in between. That's quite some variance.

15

Yep, it’s a boost driver. Supposedly only to be used with input voltage lower than output voltage, so if input voltage is = to or higher than output, I would think it’s running DD and bypassing the boost.

I would also assume the real specs would be 1.2-2.4v, not 1-4.2v. Somewhere between the mfg and vendor something got crossed in that spec.

Of course, me and drivers are like underwear and chafing... we don't get along well.

16

Thanks a lot for the review! Sticky’d.