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  #1  
Old 05-03-2009, 12:55 PM
ralph124c ralph124c is offline
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Cordless Drills: Lithium vs NiCad Batteries?

I would like to buy a new cordelss drill-preferably 18 volt (or greater). I've noticed that the new Lithium ion batteries are much smaller than NiCad-but they cost about 3X the price.
Are they worth it? What kind of attery life do they offer?
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  #2  
Old 05-03-2009, 01:16 PM
engineer_comp_geek engineer_comp_geek is offline
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Lithium-ion batteries are smaller and have more power, which is why they are popular in power tools. They also don't have as long of a lifespan as nicads. Lithium-ion batteries have about a 3 to 5 year lifespan. They also cost more to make, hence the 3x price.

Last edited by engineer_comp_geek; 05-03-2009 at 01:19 PM.. Reason: edited for clarity
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Old 05-03-2009, 02:25 PM
Chief Pedant Chief Pedant is offline
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This site http://www.greenbatteries.com/nibafa.html
has some pretty good information about battery and charger types under the FAQ section on the left.

I've been partial to NiMH over NiCads in the past, but in terms of weight and performance, Li-Ion seems to be the best. Part of whether or not it's worth it depends on how heavily you'll use the tool. I always get two batteries and a 15-min charger, then just swap out batteries if it's a big project.

Last edited by Chief Pedant; 05-03-2009 at 02:26 PM..
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Old 05-03-2009, 02:28 PM
Chief Pedant Chief Pedant is offline
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There are a few other considerations besides battery type if you are going to spend real money. For instance, some cordless drills apply much more torque at lower speeds than others, even though the maximum power might be equivalent between the two drills.
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Old 05-03-2009, 03:29 PM
Dynamo Dynamo is offline
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Lithium batteries also tend to allow for more recharges. For example, DeWalt's newer Nano-Phosphate Lithium Ion cells boast at least 2,000 charges (their words, not mine).

They also:
  • Typically weigh 25-30% less and have higher energy densities
  • Have lower self discharge rates
  • Offer higher voltages
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Old 05-03-2009, 03:33 PM
Malacandra Malacandra is online now
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As well as all the above, lithiums are generally immune to "memory effect" - I don't know if that's been successfully designed out of Ni-xx batteries yet, but a Li-xx will happily accept a charge while still part-full without detriment.
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Old 05-03-2009, 03:42 PM
lazybratsche lazybratsche is online now
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Quote:
Originally Posted by Dynamo View Post
Lithium batteries also tend to allow for more recharges. For example, DeWalt's newer Nano-Phosphate Lithium Ion cells boast at least 2,000 charges (their words, not mine).[/LIST]
But, at the same time, they have a shorter absolute life. Most lithium batteries lose capacity after a year or two, and quickly become useless by year 3 or 4.

If you're a contractor, and use the tool everyday, I can see lithium being a big advantage. But you lose that advantage if you only use it once every two or three weeks for a weekend project.

IMO, the advantages aren't worth it for that drill you occasionally use to hang pictures. They might be worthwhile if you like spending money on nicer tools and have lots of projects that keep you busy every weekend.
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Old 05-03-2009, 05:34 PM
Dynamo Dynamo is offline
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Quote:
Originally Posted by lazybratsche View Post
But, at the same time, they have a shorter absolute life. Most lithium batteries lose capacity after a year or two, and quickly become useless by year 3 or 4.
While I can't speak on behalf of all Lithium Ion products, I can tell you that one of the main reasons behind my decision to go with DeWalt was that worn, defective, or "dead" batteries fall within their 3 Year Limited Warranty program.

Depending on the circumstances, they will replace or repair your battery within 3 years of the purchase date. This usually only involves a trip to wherever the purchase was made.

Quote:
If you're a contractor, and use the tool everyday, I can see lithium being a big advantage. But you lose that advantage if you only use it once every two or three weeks for a weekend project.
Excellent point. For the time being, NiCad does make sense in the scenario you describe. Fortunately, as time and demand increases, Lithium Ions will become more appealing and feasible (cost) for even the weekend DIY-er. Just something to consider when purchasing a newer technology.

To OP, whatever you may decide, make sure you recharge them correctly. You'll do wonders in extending the batteries absolute and cycle life.
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  #9  
Old 05-03-2009, 11:38 PM
FluffyBob FluffyBob is offline
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I am a contractor and use cordless tools daily. I purchased a Makita Lithium Ion cordless set almost two years ago. Before this I have had several cordless tool sets of various types and brands.

I am very happy with lithium ion compared to my experience with nimh and nicad sets. Though theoretically the nimh should have the longer life the Lithium batteries seem to be outlasting them so far. Several nimh and Nicad sets Ive had suffered very disappointing lifespans Add to this their superior energy density and fast charge and I think it is a no-brainer for a professional.

For a hobbyist or homeowner though, there are some perfectly decent consumer grade products out there using nimh batteries, (Rona and Ryobi come to mind) that are a quarter the price.

Lithium batteries degrade with age, overheating, and by too heavy a discharge. I have a grinder with protection circuits that flash a warning and shut down if the load becomes to high.

I try to keep all my batteries charged up, charging after any moderate use and really avoid draining a battery completely. Complete discharge is bad for any battery (even nicads only require complete draining to rectify memory issues on rare occasion), as is leaving a drained battery uncharged.

I find this site useful
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  #10  
Old 05-04-2009, 12:52 AM
Magiver Magiver is offline
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Utility and cost should dictate the choice. For home use a NiCad battery works fine and the replacements aren't expensive. I have a B&D 18v Firestorm because I like the detachable head and 2 speed transmission. The lower amp hour batteries cost less than Dewalts and are aimed at the home user. As a comparison, an 18V B&D battery is 1.5 amp hours and costs $35. A dewalt NiCad is 2.4 amp hours and costs $65.

You get what you pay for so buy what you need.
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