Cheap Chinese Solar powersupply teardown and modification - Page 1
Forum section: electronics / general

author: SeanB
author_rank: Super Contributor
timestamp: April 12, 2012, 07:31:24 pm
content: I bought a cheap OHL solar powered battery pack yesterday, and this is the teardown.The box and the parts, including the foldaway pin USB charger.Charger teardown. Note the good quality, it blew up on power application, with a flash and a small amount of smoke. Note the attention to primary and secondary creepage, and the high quality of the build, with the lovely voltage regulation used.The main unit inside. Looks like the original battery was a recycled unit, made by Sony in Japan...... Looking at the plant location it has been in the news recently. Note the charge regulation, consisting of a single diode and a CBB 4.7 ohm resistor. The battery does not hold charge long, i tried charging via USB, and it held up for around a minute after disconnection, and the foilpack cell is rather loose, with the electrodes barely holding on. The inverter inside does work well, made by MicrOne, and is a 3 terminal part in SOT89, with only 3 external components. Switching of the unit on and off is done by plugging the output lead in, which connects the ground lead of the regulator to the battery negative.After some modification, I placed a battery with a built in controller in place of the Fukushima made Sony, and replaced the very burnt 4R7 SMT resistor with a recycled 10R 0.25W unit from a donor board. Added a replacement capacitor instead of the 47uF crapolytic, used a 47uF 10V tantalum unit, and linked out the regulator, after removing the active device. The blurry photo insert was taken with the unit powering my camera, blurred because the camera focussed on a wire, not for any other reason.Now it is a better unit, and will be used as an external battery for my point and shoot camera, hopefully providing better runtime than NiMH cells, with the added bonus of solar charging if needed. most of the time it will be charged via USB, with the provided lead, which actually is a proper USB lead and not just 2 wires.

author: T4P
author_rank: Super Contributor
timestamp: April 12, 2012, 08:22:43 pm
content: In other words , completely crap .1st : Charger blew up . 200mA ... pretty useless for charging phones .2nd : Recycled battery just doesn't work . So you pretty much wasted your money but luckily you had a spare nokia battery lying around .And anyway electrolytics are not crapolytic , unless you are an AUDIOPHILE .Most common tanty's can get secondary breakdown and burst into flames with high current .Buy a Epcos/Panasonic electrolytic and you will know they aren't CRAP .

author: SeanB
author_rank: Super Contributor
timestamp: April 13, 2012, 04:39:05 am
content: True, total OHL junk, but a nice casing............Probably made from recycled stuff, so the cap and battery were on the way out. I have a HDD where the tant did a flame out and burn, runs still without it.

author: amyk
author_rank: Super Contributor
timestamp: April 13, 2012, 08:05:24 am
content: That's the same casing they use for iPod nanos and their clones, with a larger opening cut into it. The plastic frame inside was probably intended for such a player too, as does the "MP3 power supply" on the wallwart. I guess someone had a surplus of these cases and solar panels.

author: T4P
author_rank: Super Contributor
timestamp: April 13, 2012, 12:54:17 pm
content: Quote from: amyk on April 13, 2012, 08:05:24 amI had bought a portable charger while in china that uses the same case , luckily not a recycled battery .

author: saturation
author_rank: Super Contributor
timestamp: April 13, 2012, 01:32:49 pm
content: This is a key thing when buying most all stuff from eBay & China, and your reward is a working item.The solar charger is an interesting idea particularly in the Pacific, and on boats. However, we are usually too far from shore to use cell phones and if we have no power, we are in deep trouble. One thing needed on boats are very good floating power supplies, usually brick/wallwart types, as the generators give more erratic AC, and sealed supplies protect the guts from salt, humidity until the case deteriorates from UV exposure.Quote from: Mechatrommer on April 13, 2012, 04:54:10 am

author: Agent24
author_rank: Regular Contributor
timestamp: April 21, 2012, 10:44:15 am
content: Quote from: Dave.S on April 12, 2012, 08:22:43 pmYeah, sure there are some good brands of electrolytics, but you must be crazy if you think this unit would have used capacitors remotely near the quality of a Panasonic or such.

author: T4P
author_rank: Super Contributor
timestamp: April 21, 2012, 11:32:13 am
content: Quote from: Agent24 on April 21, 2012, 10:44:15 amCertainly .