NiCd vs Li ion

[ishium 80439]

A few years back my old NiCd's for my 18V Milwaukee set had run their course and I was looking for new batteries. I got sold on the Li ions. Overall I have been slightly disappointed with them. The one good side is that they still operate and hold a charge the same as the day I bought them.

However I think that the hype surrounding them is/ was overblown. They don't seem to last any longer between charges and the no fade power thing is as much a curse as it is a blessing. The real kicker though is that they just don't have the same oomph that NiCds have. Yesterday I had a 5/8" auger chucked up and my drill just couldn't get through this particular joist. I snapped in a NiCd my journeyman had and it ate right through it.

So I have a few questions. Has anyone else had the same experiences? Did I buy too early? That is to say did I buy first generation batteries that may have gotten to market before the kinks were worked out? Have they improved any over the past several years? If needing new batteries now which route would you go?

Thanks.

 

[One-eyed Jack]

Check the milliamp rating of your Nicad vs Li-ion. I think you will find the Nicad are 2000 vs 1500 on the Li-ion. I prefer the lithium batts hands down. If you get a 2000-3000 in the lithium you will be amazed at the diff. Caution, "DO NOT" charge lithium batts with your nicad charger. Fire/explosion very very real possibility.

 

[rich9112]

Milwaukee Batteries

Milwaukee Batteries

I've found that if you leave your milwaukee Lithium-Ion batteries on the charger overnight once in a while they seem to have much more life. Also, remember that those batteries have a warranty which rocks. I've swapped mine when they died for new ones (no charge). They can verify how many cycles they've been through and manufacture date via the electronics.

 

[480sparky]

LiIon batterys have a different methodology of discharging and recharging.

Whereas you are used to completely draining NiCads, that's not the recommended practice for LiIons. LiIons prefer light discharging, then full recharge.

 

[MarkyMarkNC]

Lithium Ion battery cells can not source as many peak amps as a NiCad battery cell can, so it is possible the motors are not seeing the same "oomph," at full load, as you put it.

To me the trade-off in weight and run time still give the advantage to Lithium Ion.

 

[mikeames]

I have had no problems with them. The BMS (battery management system) built into the battery and charger prevent from over charging so overnight shoul dhave no performance difference. What can hurt these battery is complete discharge which often happens on a job. Thats is a curse. The other pluse is cold will nto affect these unlike the Li-ion.

 

[kbsparky]

What is the so-called "curse" when a complete discharge occurs? Do they quit for good?

I have a couple of portable radios that simply "died" one day and now won't take any charge.

 

[480sparky]

What is the so-called "curse" when a complete discharge occurs? Do they quit for good?

I have a couple of portable radios that simply "died" one day and now won't take any charge.

Some lithium-ion batteries fail due to excessive discharge. If discharged below 2.5 volts per cell, the internal safety circuit opens and the battery appears dead. A charge with the original charger is no longer possible.

 

[mikeames]

What is the so-called "curse" when a complete discharge occurs? Do they quit for good?

I have a couple of portable radios that simply "died" one day and now won't take any charge.

I wish I could tell you. I learned this info from building an electric go kart and researching batterys for electric vehicles. Li-ion have the best energy density but they are very unstable. If they get too hot they will explode. If they are discharged fully they will die. I am not a chemist but this is what I have read. As a result the batterys have special chargers and must have a BMS (battery management system) that monitors each cells temp and voltage. Overcharging leads to fire thus the BMS.

The advantages are, high energy density, no memory effect, not affected by cold.

The disadvantags are they have a limited life regardless of usage. They degrade as soon as they are made, but their cycle life is great. This life is a few years 2-3 maybe..... I am not an expert.

They also have a high "C" which means they can output large amounts of current quickly with out damage. Conversly they can take a large amount of charge current quickly. Lead acid is totally opposite.

Thats all I know. I chose not to use Li-ion on my go kart because of cost and complexity. the leading Li-ion manufacturer is A123 syetsm which supply the cells for Dwalt. Some guys actually take these packs apart to use the cells in a custom made pack.

heres and example http://www.youtube.com/watch?v=qVq94aN5mNM&feature=related

 

[ishium 80439]

Thanks for the responses. I will look into the mah of my batteries to see what they are rated. I'm also considering taking them back to a Milwaukee shop to see if they bench OK.

When I said "curse" about the discharge is being on top of a ladder and you drill one hole fine, go for the next one and you have bubkus. At least w/ NiCds you are prepared for the drain/ die and can judge whether or not it is time to go get the other battery or if you are good for a few more. I find the meter on the front to be an indication at best. I can get a battery off of the charger and have it show full charge. Drill a few tough holes and it will go down one or even two levels. Wait a few minutes and it is back up again.

 

[jeremysterling]

Interesting thread. Good topic. I have 4 dead DeWalt NiCd's I'm thinking of refurbishing (at ~ $30 each). Do the Milwaukee battery comparisons have similarities to DeWalt batteries?

 

[TOOL_5150]

I prefer dewalt nicads over their Lithium packs. The sudden turn off when the pack reaches its lower end limit has screwed me more times that I would prefer.

~Matt