Nickel Cadmium batteries (maintenance-free) charging methods

[syng]

According to rechargeable batteries applications handbook, it states that constant potential charging of sealed NiCd batteries is strongly discouraged. And Vantex maintenance free NiCd batteries, it allows constant potential charge. So is the charging methods (eg. constant potential ) depends on the specification of NiCd batteries but not in general basis?

 

[moltenmetal]

Recommended charging and discharging methods vary strongly depending on battery chemistry, but unless the battery contains its own battery management circuitry (i.e. like most lithium ion consumer batteries) the proper way to charge them for maximum life and capacity maintenance shouldn't vary much between manufacturers for the same battery chemistry.

I've never seen a Ni-Cd battery that was anything other than "maintenance free"- the only batteries requiring that kind of maintenance (i.e. maintaining fluids) are lead acid. The only maintenance that a Ni-Cd needs is a controlled charge and avoidance of over-discharge. Over-discharge is the real killer for most multi-cell batteries.

Constant potential charging is tolerated rather than truly acceptable for any battery, because if you select that constant potential too low you won't get a truly full charge, and if you set it high enough to achieve a full charge but fail to shut it off at the end of charge, you will over-charge and ultimately do damage to the battery. To my knowledge, that's the case with ANY battery chemistry, but the voltage sensitivity, the loss of charge due to setting the constant voltage too low, and the severity and nature of damage due to over-charging, varies greatly from battery chemistry to battery chemistry. For some chemistries, it's no real problem at all- within limits of course.

 

[mikekilroy]

'regular' nicad batts must be constant current charged. "regular" lead acid must e charged constant voltage.

your vantex is not a "regular" nicad.

google nicad then google vantex and see how they are not the same animal.

http://www.alcad.com/content/download/705/4796/version/5/file/Vantex+NG_TM_en_0613_LD_protected.pdf

This vantex is like a lead acid battery with elecrolyte and nickel and cadmium for + and -.....

So since they are a unique 'different' design, they can charge however they decide is best

http://www.KilroyWasHere<dot>com

 

[ScottyUK]

I've never seen a Ni-Cd battery that was anything other than "maintenance free"- the only batteries requiring that kind of maintenance (i.e. maintaining fluids) are lead acid.

Just because you haven't seen them doesn't mean they don't exist. Click me and then you will see!

 

[moltenmetal]

Interesting...vented definitely means replacement of the electrolyte. I stand corrected- thanks ScottyUK!