smart NiMh/NiCd charger

[Max]

Hi,
here are links to some schematics that could be of interest.

http://www.angelfire.com/electronic/hayles/charge1.html

http://home.planet.nl/~havinga1/BattCharger/BattCharger.htm

http://www.opend.co.za/hardware/nimh1/nimh1.htm

DISCLAIMER: I must tell you I didn't test the circuits... and don't know much about so do at your risk.

Kind regards,
Max

[Götz von Berlichingen]

The first Link "Intelligent NiCd/NiMH Battery Charger" looks bad - no Firmware.
One has to buy the programmed PIC for $AUD 25.
I think i can buy a complete Battery Charger for this Money.

The 2nd and 3rd link look better, but still no smart Design.

If you are not afraid to burn your House down, try the Li-Ion Charger at :
http://mondo-technology.com/

Delta-Peak Charger for NiCd and NiMh, up to 7 Cells :
http://www.sprut.de/electronic/pic/p...kku2/akku2.htm (sorry, german)
This Guy knows how to use a Microcontroller.

[Max]

The first Link "Intelligent NiCd/NiMH Battery Charger" looks bad - no Firmware.
One has to buy the programmed PIC for $AUD 25.
I think i can buy a complete Battery Charger for this Money.

The 2nd and 3rd link look better, but still no smart Design.

If you are not afraid to burn your House down, try the Li-Ion Charger at :

http://mondo-technology.com/

Delta-Peak Charger for NiCd and NiMh, up to 7 Cells :
http://www.sprut.de/electronic/pic/p...kku2/akku2.htm (sorry, german)
This Guy knows how to use a Microcontroller.

Hi,
I use some U2400 based chargers for most of my batteries... both old NiCd stuff (those still working) and NiMh, just little modifications required to match bettery kind etc.

The IC is old stuff but still usable today with good results. I really don't care much of using an MCU for charging batteries... another member asked for some plans and I provided some (interesting ?) links.

BTW I tryed many newer chargers... and are total crap... batteries burnt and damaged in few time... some are simple rectifiers and transformers! Others are switching kind but messy about right charging params...

Only really good I found was that impulsive charging like the U2400 circuits realize : consider that I own 15years old NiCd batteries that still work good! Charged and discharged with that stuff... many hundreds times.

I don't like the ones that made too fast charges... too hot running , too batteries lost.

Kind regards,
Max

[Qiaozhi]

Hi,
I use some U2400 based chargers for most of my batteries... both old NiCd stuff (those still working) and NiMh, just little modifications required to match bettery kind etc.

The IC is old stuff but still usable today with good results. I really don't care much of using an MCU for charging batteries... another member asked for some plans and I provided some (interesting ?) links.

BTW I tryed many newer chargers... and are total crap... batteries burnt and damaged in few time... some are simple rectifiers and transformers! Others are switching kind but messy about right charging params...

Only really good I found was that impulsive charging like the U2400 cir cuits realize : consider that I own 15years old NiCd batteries that still work good! Charged and discharged with that stuff... many hundreds times.

I don't like the ones that made too fast charges... too hot running , too batteries lost.

Kind regards,
Max

I've heard that you can revitalize old NiCd batteries, by connecting a voltage source across them of twice the voltage, but for only a few seconds. Personally, I've never tested to see if this is true. Might give it a go later; or has anyone tried this before?

[Max]

I've heard that you can revitalize old NiCd batteries, by connecting a voltage source across them of twice the voltage, but for only a few seconds. Personally, I've never tested to see if this is true. Might give it a go later; or has anyone tried this before?

Hi,
I never tested... I get very long life for each battery... when I see some are damaged or not hold anymore the same capacity I simply discard them and buy new, today I buy only NiMh, as workhorses, but have still old NiCd working.

I don't know if that method works... interesting to test with some old battery sooner or later...

Kind regards,
Max

[Unregistered]

A better method that has worked for me over many years is to get a large Electolytic capacitor (~10,000uF) and charge it with about 12 volts. Connect the dead battery to it and give it a blast. The high voltage/current burst burns away the internal whiskering that shorts out the battery. Repeat the procedure until a multimeter verifies that the cell is no longer internally shorted. The pulse is of very short duration and will not harm the battery.