Lithium-ion Drill/Driver or Combi Hammer?

[LyNx]

enjoy your new drill Mike

 

[Alf]

Pack it in, gents, otherwise I can see it being drills at dawn... :wink:

Well, Mike, I refrained from comment 'cos I've only ever had experience of sub-£100 drills and been universally disappointed in them. However, have you considered a brace and bit...?

A'duckin' 'n' a'runnin', Alf

 

[Sonic]

I was merely pointing out that most regular users of cordless power tools don't find the limitations of NiMh or NiCd batteries too onerous. Obviously if the tool only has one battery, (as with very cheap ones) it is a PITA when you pick it up and find the battery dead.

I own a digital camera and video which both have Li Ion batteries, and the fact that they still are useable after several weeks lying idle is a great benefit. But even when I don't use my drill or cordless saw for a long time, I find that even if the fitted battery is dead, the "spare" always has enough charge to last me until the first one can be charged. It helps that my saw and one of my drills share the same type of battery, so I have 4 batteries between them. I also have one of the little Bosch IXO ? screwdrivers that do have a Li Ion battery, but somehow I seldom use it - for those little jobs an ordinary screwdriver seems less bother !

I made no recommendations because I also felt that my drills (a 12V Bosch blue, an Eberspacher 18V drill driver and an ancient Hitachi) were not in the same league as the proposed purchase - however they do everything I need. If (very occasionally) I need to drill a dirty great hole in concrete, I get out my mains SDS drill ! I am sure that the new drill will be very impressive, I personally could not justify the expense - there are other toy... tools that I want more !

Colin S

 

[Jake]

the battery gets to a point where although it is still running it is not powerful enough to turn the screw all the way home. If you then recharge it from this point (partial charge), in the end you are going to get the memory effect.

Memory effect is largely a myth. I've never had a tool that suffered from it, only from cells that gradually deteriorated with time and use. Cordless tools wouldn't have lasted on the market very long if memory effect actually affected tools this way.

 

[Jake]

By the way, you are not supposed to fully discharge batteries before recharging them - indeed draining them below a volt or so will ruin the battery, permanently.

 

[Colin C]

Jake if I have it right that is for NiMh batterys not NiCd, as NiCd are better if you run them right out

 

[PowerTool]

Colin - Jake is perfectly correct - batteries are made up of 1.2V cells,and running any cell below about 1.0V can damage them.
Google for "memory effect" and there are a couple of good articles which explain that the term actually means "voltage depression",as memory effect is virtually impossible to creat outside of lab conditions.

A well-looked-after NiCad battery is supposed to be able to be recharged twice as many times as a NiMH battery.Li-Ion batteries have the advantage of not loosing charge when stood.

Andrew

 

[Colin C]

I have seen memory effect out side of a lab but that was with army radio batterys and that was a pain, when you thought you had a charged battery to find after about half an hour it was dead.

 

[Woodythepecker]

Be it in or outside a lab, and whether it is as the manufacturers call it 'Memory Effect' or as Andrew and Google do 'Voltage Depression'.There is no getting away from the FACT that the batteries in Mike's drill only last half the time that they used to between charges.

Call it largely a MYTH or the plane and simply TRUTH, I personally (as the user) have witnessed the deterioration of these batteries over the last 6 months, or so.

The problem here may have been Mike's use of the words Memory Effect, when a faster deterioration of the batteries than you would except, may have been a better description.

Can i ask how long other members would expect either their NI-CD or NI-MH to last before you binned them and bought new one's for your drill?

As i have said, i had been using Mike's drill when he was in the US, and so because i may have done something to ruin the batteries and the fact that it is his birthday on May 3, i have decided to buy the Makita BHP451SFE for him. I am sure that he will be well chuffed.

Regards

Woody

 

[Jake]

If it is voltage depression, the real cause is overcharging and the cells can be reconditioned by discharging fully (to 1v) and recharging fully (but not overly) a few times.

As with all batteries, they have a limited life. NiCads are the toughest and should give around 1000 charging cycles. NimH is less, and Li-Ion will last around 500 cycles.

Doesn't stop it being a nice tool, though - should be quite a lot lighter than its niCad equivalent for a start.

 

[Anonymous]

no "memory" effect, where effective capacity is lost through repeated partial charging.

No rechargable batteries suffer memory effects these days. People who believe they do are 10 years out of touch

NiMH are superior to NiCad as rtegards energy density but Lithium Ion are the current best for energy density and hiold ntgheior charge longer and thus number of holes per charge but are expensive. NiMH is the best choice unless a drill with Lithium Ion can be found at the same or similar price

 

[Anonymous]

I have seen memory effect out side of a lab but that was with army radio batteries and that was a pain, when you thought you had a charged battery to find after about half an hour it was dead.

Memory effect does not exist in modern batteries. This is a fact known to all electronics engineers.

What you are more likely to be seeing here is a battery that has gone past its useful service life. A typical Ni Cad battery will only be able to sustain around 600 charge/discharge cycles - NOTE that a charge/discharge cycle does not mean it was fully exhausted and then recharged, simply that some energy was removed and then replaced.
After about 600 cycles, it is more-or-less useless, the deterioration is not immediate at 599 charges but a gradual deterioration over time.

 

[Colin C]

Memory effect does not exist in modern batteries. This is a fact known to all electronics engineers.

Not being an electronics engineer ( Antique restorer / cabinet maker ) I will just I have been put right :shock: , but what was said is that memory effect does not happen and was just saying that I have seen it.

Tony , if you do have to correct some thing said on here , I do hope you find a better way of putting it . We are all here to learn from each other

 

[Anonymous]

Tony , if you do have to correct some thing said on here , I do hope you find a better way of putting it . We are all here to learn from each other

Colin, I really do apologise. When I wrote my post, I was simply stating a fact that people in my profession are well aware of. Now I read the post, it does appear rather condescending. I do apologise.

The thing that people once called 'memory effect' was evident in Ni Cads many years ago, however, the chemistry and manufacture has now improved to the point that it no longer exists.

 

[Colin C]

Tony is not a problem as from the post of yours that I have raed before it did seem not like you.

It was over 10 years ago that I saw in the army :shock: ( it just seems like yesterday )

 

[Mike.C]

Tony, i do not for one minute think that you do not know what you are talking about, but when manufacturers write articles like this (bottom of page) http://www.makitauk.com/index.php?page=70 you can see why we previously thought that memory effect still existed.

Tony wrote:

No recharable batteries suffer memory effects these days. People who believe they do are 10 years out of touch.

So rather than being 10 years out of touch, we or at least I thought that i could trust an article written by a manufacturer.

Now as memory effect does not exist anymore, and the fact that i have not charged my batteries anywhere near 600 times, can anyone give me an idea what may be wrong with my batteries?

Thanks for the info.

Cheers

Mike

 

[Mike.C]

Come on Guy's your really making this hard work. I want to find out what is wrong with my batteries so that i do not make the same mistake again.

Tony what do you think of Makita's artical above?

Cheers

Mike

 

[Jake]

It is probably a combination of cheap cells in the battery and a charger that is not sophisticated enough - some of them are very crude and don't even stop charging after the appropriate time. Try draining the batteries down until the drill stops working (in free air, as it were), charging for precisely an hour (or whatever it says on the charger), and repeating a couple of times.

 

[Mike.C]

Cheers Jake, much appreciated.

Mike

 

[Alf]

Mike, we're not actually getting paid to offer assistance here, ya know, it's strictly voluntary. Please don't chivvy, there's a good chap. As it happens I do have some info you might find useful. Could you drop me an email (it's on my website) so I can send you an attachment?

Cheers, Alf