Replacement batteries: Ni-Cd vs Ni-Mh

[Mark42]

I'm shopping for replacement batteries for two Ryobi cordless drills. One is 12v and the other 14.4v. I see that both batteries are available aftermarket in Ni-Cd and Ni-Mh. The original is Ni-Cd. <br /><br />What is the difference between the Ni-Cd and Ni-Mh besides the price (Ni-Mh is quite a bit more)? <br /><br />Will the Ni-Mh battery work in the OEM charger?<br /><br />Thanks,<br /><br />Mark.

 

[Dunaruna]

Re: Replacement batteries: Ni-Cd vs Ni-Mh

NiMi don't have a memory.<br /><br />Some chargers do both, some don't. Check with ryobi.

 

[ZmOz]

Re: Replacement batteries: Ni-Cd vs Ni-Mh

And NiMh last longer. NiCd is far inferior unless you don't have a charger for NiMh.

 

[Mark42]

Re: Replacement batteries: Ni-Cd vs Ni-Mh

I checked with the battery supplier and I was surprised to hear her say NOT to use the Mh battery with Ryobi brand Cd charger. She said it will cook the battery and to stay with the Cd chemistry if using the OEM charger.<br /><br />This goes along with what I could find on Google. <br /><br />Ordered two batteries, the 12v is 2000 mAh and the 14.4v is 2200 mAh. Seeing as the originals were 1400 and 1500 (best I can tell from OEM suppliers), these should be an improvement. Still cost $68 (free ship) for two batteries. Yikes!

 

[Dunaruna]

Re: Replacement batteries: Ni-Cd vs Ni-Mh

Sometimes it's cheaper to buy a new drill, especially when they have a special offer of 'two batteries' included.

 

[Andrew Leigh]

Re: Replacement batteries: Ni-Cd vs Ni-Mh

Mark,<br /><br />saw the thread to late but for future reference.<br /><br />I hate it when suppliers force you into buying product based on lies. The basis of both batteries is very similar with differing chemistry. NiMh is a newer generation battery normally capable of producing more power per volume. I also think that manufacturers were having an environmental problem with Cd.<br /><br />The recommended slow charge cycle is the same for both and is normally 1/10th of the rated Ah capactity of the battery for 12 - 14 hours. This of course can be sped up by increasing the charge current and reducing the time. Intelligent chargers do this.<br /><br />Your NiCd charger would have done the job perfectly. I have both NiCd and NiMh batteries and I use my home built NiCd constant current constant voltage charger, have done for years, with no problems. The difference between these batteries and lead acid is that they require a controlled constant current.<br /><br />I am surprised that your google search showed the opposite. My google search supports what I say, type in "charging NiCd and NiMh".<br /><br /><br />Cheers<br />Andrew<br /><br />PS: Old NiCd's used to have a memory, that was many years ago. Later NiCd's do not have a memory.

 

[Mark42]

Re: Replacement batteries: Ni-Cd vs Ni-Mh

Originally posted by Dunaruna:<br /> Sometimes it's cheaper to buy a new drill, especially when they have a special offer of 'two batteries' included.

That's what I did last time and that is how I ended up with 12 and 14.4v drills. At any rate, these batteries are highter rated mAh than the oem's, so hopefully they won't be going back to the charger as often as the last set.<br /><br />BTW, the old 12v Ryobi drill is still as stong as the day I bought it. I like it better than the 14.4v drill because the hi speed gear is higher speed than the hi gear on the 14.4, and it is smaller so it gets in the tight spaces easier (like between floor joists with a 3/4" speed bit). The 14.4 is a brute in both low and high gear and I use it for nut driving too. <br /><br />Maybe next time the batteries die I'll get a 18v setup.<br /><br />Andrew, <br /><br />Great info. Wish I read it before ordering. Next time I'll go with the NiMh.<br /><br />Now I'm supposed to toss these dead Ni-Cd batteries in a fire, right?