REXSO R1 LED Camping Light (Lantern) – Warm White 2835 SMD LED mod

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sac02
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REXSO R1 LED Camping Light (Lantern) – Warm White 2835 SMD LED mod

REXSO R1 LED Camping Light (Lantern) – Warm White 2835 SMD LED mod

I got THIS light from GearBest a while back on sale for $6 or $7 I think.

In stock form, my observations were not that great:

  • Bad battery life – the included battery tested as 1600mAh. I previously installed a Panny NCR18650B 3400mAh battery, that installation is not shown here. (Just desolder the crap stock battery and solder in the new batt.)
  • Very cool white light – very bad for outdoors camping IMO
  • UI: White light, blinking red light, off. That’s it, I wish it had at least hi/lo for white light.
  • Recharging circuit uses obsolete mini-USB instead of common micro USB (so you would probably need to carry a dedicated cable for this light)

But, BLF is for taking cheap stuff and making them fit our personal desires, right? So I began to tackle item #1 – cool White light. For outdoors camping, Warm White is a requirement, IMO.
(I plan to install a different driver and charging circuit later, to address items #2 and #3)

I forgot to take a picture before I began to disassemble.

Here is the LED board (MCPCB) with the top popped off. The stock LEDs are 3528 cool white. I will replace them with Warm White 2835 emitters (2835 are newer/better than 3528).

I was able to mount the 2835 WW and the stock 3528 CW emitters on some XP-footprint MCPCBs (remember XP-footprint is 3535).

Wired them up.

Test them at low current.

Note the obvious difference in both output and tint in the pic above, and in this pic.

Back to the light. The driver is underneath the LED board. The first thing I did was remove the red and black wires running to the red LED (can also be seen above), I have no need or want for a blinking red LED.

Get the mini hotplate warmed up.

Begin reflowing LEDs.

Complete! (before cleaning up the board) Took about 10 min.

Reassemble.

Test.

Finished beamshot of Rexso lantern. 15’x20’ bedroom, pitch black (we double sets of blackout curtains, wife used to work nights sleep days).

Ceiling bounce. More even soft lighting (as you’d expect).

Using the magnet base of the lantern I stuck it to the ceiling fan firing down. Also as expected, the lux in the center of the room is higher, and falls off to the sides.

This is a good light level for emergency lighting in a power outage but probably too much for inside a small tent camping, that is why I intend to install a driver with mode options.

The “test pic” above is with the camera exposure turned down (and with the diffuser cover off of the light). The new 2835 LEDs were significantly more powerful than the stock 3528 ones – with the new LEDs light was pulling 2.25A (sorry, I forgot to measure before) and was MUCH brighter. VERY bright. TOO bright in fact, for a camping light that has no lower mode (currently) and will be used in the dark. I added a current limiting resistor (I had to put a couple in parallel, I think I wound up around 5.5ohms?) to get down to around 0.26A. 0.26A seemed to be a good amount of light to light up my bedroom.

As mentioned, in the future I will add a multi-mode driver to give L/M/H modes which will make it much more useful. I will just use a leftover 7135 driver, probably 4*7135?

I will also remove the mini-USB charging circuit board and install a TP4505 micro-USB board so that it can share the same cable as other modern electronic devices.

Edited by: sac02 on 09/11/2017 - 23:20
giorgoskok
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Nice mod !

Last pic with the new leds is great , nice ww tint .

MRsDNF
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Nice mod sac. Thumbs Up

My current and or voltage measurements are only relevent to anything that I measure.

Budget light hobby proudly sponsored by my Mastercard and unknowingly paid for by a hard working wife. 

djozz said "it came with chinese lettering that is chinese to me".

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

sac02
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Updated with beamshots of the finished product.

Also, the cost of 100pc warm white 2835 SMD LED was $3.99 on Aliexpress, I used 38 of the 100.

Intending to use a leftover 7135 take-off driver (free) and a $0.50 TP4505 charge circuit, the total cost for this is easily under $10.

This was fun and the light is totally useful, but the final product is just “OK” IMO. My main issue is the limited runtime provided by the single 18650 (I like not even worrying about runtime on a camping light even if I use it for 6 hours per night for several nights).

I’ve got another cheap lantern mod in the works that I will post soon that I like a lot more.