battery charging

[beambeam]

Do you need a special charger for i.2 volt nicd storage batteries or can you use a lead acid charger.



                                                                                      thank you
                                                                                        jim

[Bruce S]

NiCd batteries need special charging. They need constant current charging. You can in emergencies,,, use a standard battery charger, but ONLY for a short while since the voltage of a NiCd is lower.


Hope this helps;
Bruce S

[beambeam]

Thank you Bruce.Where could i find a charger for these bats


                                         Jim

[Bruce S]

Thank you Bruce.Where could i find a charger for these bats


                                         Jim

google will give you thousands of results. YOU could even build your own if you are handy with a soldering iron.
How is your electronic skills?

AND which type of NiCds are you speaking of, I/we will need much more info than you've given.
I generally DO NOT give out how-tos without knowing your skill level since a wrongly placed part could cause serious damage to either the battery or the person OR both. The chemical makeup of these types of batteries are deadly even just on the surface of the skin.



 

[beambeam]

Hi Bruce;
I'm a retired electrician.I worked with batteries on dc gantry cranes.I just never had to go into the batteries like i do now.The batteries i mention are 1.2volt alcad.They are 14.5 inches high by 6in long some are 3 in wide and some are 2.5 wide.they are from 140ah down to 120ah.I am also into hho boosters.I am used to working with potassium hydroxide. I have about 8 or 10 pounds of it on hand.I put together an effie and one of zero's pwm kits.I would like very much to have a charger for these batteries I have one that i made out of a small welder i tapped the xfmr about half way and get about 15 volts out of it.I have four diodes out of a much larger welder.I just have the full wave bridge with no filtering.It charges lead acid 12v at about 15 to 23 amps.(adjustable armature)Could this be used to charge the nicd's?If you can steer me in the right direction to build my own i would appreciate it.I live in pictou county nova scotia .

                                                                                              thank you
                                                                                                 jim

[dnix71]

http://en.wikipedia.org/wiki/Nickel-cadmium_battery

NiCads have a nasty negative temperature coefficient. That's why you have to use constant current charging and limit the current to a safe level. NiCads also have a memory so some deliberate discharge to a fixed voltage helps preserve capacity.

http://www.powerstream.com/NiCd.htm

In simple terms, the voltage on a nicad doesn't change much near the top so you can't tell from voltage if its full. The internal resistance drops off a lot, though, so when it's full the battery begins to heat up as the chargers current is wasted as heat. That's when you know to quit.

[beambeam]

Thank you dnix71.


                                                   jim