How to test jewellery for cadmium?

These days a lot of jewellery is testing as containing dangerous levels of lead and cadmium, mostly Chinese imports.  How could a consumer test jewellery for cadmium, easily and cheaply at home, please?  I can't find anything online about how to test for cadmium.

Question by Lickyboomboom 3 years ago  |  last reply 2 years ago


How many Volts can a 1.2V Nickel-Cadmium battery take?

Hi! I (still) need some help with building a solar charger... I want to charge a Nickel-Cadmium battery (1.2V) with solar cells from a garden light. Unfortunately these cells give me 5V in full sun... Will the battery take the 5 Volts without damage? The amperage is fine, so no questions about that...

Question by Fypsigon 5 years ago  |  last reply 5 years ago


DIY Rechargeable Cell Chemistry?

Hi i was wondering if there was any electrically reversible battery chemistries that can be made from around the house materials like copper wire, iron nails, galvanized nails, graphite rods, aluminum foil, and other items like those.

Question by LiquidLightning 8 years ago  |  last reply 6 years ago


I need help building a 1.3V solar charger from garden light cells?

Hi! I need some help with building a solar charger...I don´t know much about electronics, maybe one of you has the patience to answer a few questions? The device I want to charge has a label that says 1.3V=2W (there is 1 rechargeable Nickel-Cadmium battery inside), the wall charger is labeled 1.3V=1500 mA... I have 2 solar cells from garden lights, they both were used to charge two 1.2V batteries with 600 mAh (in series). That´s all I know about them, I have no way of measuring the output... My questions: 1. How many Volts (at least) does it take to charge that device? 2. How many Volts can the battery take without getting damaged? 3. How many Volts do I usually get from those garden light cells? If they charge 2 batteries (1.2V) in series it should be 2.4V, right? 4. If 2.4 Volts is too much for the device, how do I limit it? I would like to build the charger without buying a multimeter and the parts will be salvaged from other stuff...I hope... I know those are a lot of noob questions but I would really appreciate your help!

Question by Fypsigon 6 years ago  |  last reply 6 years ago


I rebuilt a battery and it didn't work. why? Answered

Today i got the 12 batteries required to rebuild the battery in my powerbook 190. i dont know the condidtion of the parts inside the laptop, but it must still be in a somewhat working order because when i hooked it up to an ac adapter (12v, 15a) before, its power light turned on and it made some noises. it didn't fully turn on though, because it needed 24v, not 12. hoping that rebuilding the battery pack would help, i bought 4 cordless phone batteries, each consisting of 3 smaller batteries and equaling 3.6v. all together that created the 14.4v that is needed to replace the original, acid leaked batteries. i wired them in series to get the 14.4v. I think that it may have not worked because the original batteries were nimh (nickel metal-hydride), and these new ones were nicd (nickel cadmium). Upon observing the internals of the laptop earlier, before i bought the batteries, i noticed some peculiar things: -there were a few spots where some components were added, (eg- resistors, capacitors, jumper wires, all were smt) -a unbranded piece in the battery power area, labeled on the board as XFER1. it is black and has five connections on each side of the component, which seem  to have copper wires attached to them leading inside the component. -no marked fuses on the board. the (apple released) manual for disassembling the machine states "you can blow a (soldered) fuse on the board", but there are no spots where a fx (x representing a number, eg: f1) is present, and most of the smt components in the suspected area are not marked and lok much like the same piece. can anyone help me figure out what may be wrong? the ac adapter port works but the battery doesn't, would uploading pictures help people help me?

Question by zack247 8 years ago  |  last reply 8 years ago