NiMH batteries for driling

[nickwilliams]

Has anyone built up an external battery pack of big NiMH batteries for use drilling shot holes with a Bosch or Hilti drill? If so, what did you use and what's been your experience of using it? How do you charge it? Have you got any direct comparison information (e.g. length of hole drilled) with other battery technologies?

I've yet to see anything better than the 22 cell 'F' sized NiCad pack which I have for my Hilti TE5A, but I'm interested to know whether NiMH's have come far enough to be considered a viable alternative yet.

And, before you bother, experience tells me that the conditions of use for a drill used for shot holes are such that comparisons between different battery packs used for other applications are not much help - comparing the behaviour and capacity of 'AA' or "C' sized cells used for lighting or drilling small bolt holes ain't going to tell me what I want to know.

Nick.

 

[Leclused]

Why not switching to Lithium - Ion ?

A test-report made by Paul de Bie (belgian Caver Goeroe) wich compares  bosch <==> hilti can be read here. In our club we currently use an old hilti with external lead batteries + a bosch lithium-ion and we recently also bougth the hilti lithium - ion. And for the serious work we have a 220V Hitachi

Report in dutch :

http://www.scavalon.be/downloads/TEST%20BOSCH%2036V-Li%20versus%20HILTI%20TE6A.pdf

BR

Dagobert L'Ecluse (SC Avalon)

 

[shotlighter]

I built a pack up for The Crewes Bosch a few yesr ago using 4Ah NiMH cells. Strangly they over heated during discharge - too small/ too high internal resistance for drill current probably. I've still got one of the cells at home - If you like I'll mail you a pic of it when I get back (in US at moment) - its seriously black!

 

[AndyF]

I built a pack up for The Crewes Bosch a few yesr ago using 4Ah NiMH cells. Strangly they over heated during discharge - too small/ too high internal resistance for drill current probably. I've still got one of the cells at home - If you like I'll mail you a pic of it when I get back (in US at moment) - its seriously black!

AFAIK that is a problem.... The high internal resisitance means that you can only get good efficiency out og them in a relatively low current application. In high drain situations (like drilling) they get a bit clobbered. Can't speak from experience though.....

A pack of Li-ion batts with capacity for powering a drill would be a bit of a bomb!... and there is a high risk of over discharge damage without fancy protection circuits and off-the-shelf circuits aren't designed for that kind of current/loading.

NiCad 'F' s are pretty good really, but will shortly get rare as the new EU regs kick in...

 

[Rob]

Sorry can't be of much help, other than pushing the importance of this thread.

11Ah NiMH D cells going for £11 for 2 on eBay! 

There's potential for a satifyingly cheap setup there. And with Bosch, Makita, Panasonic, Hitachi, Milwaukee all doing NiMH batteries for their drills, i reckon the time has come Nick.

BTW if your gunna order a load, yes please, bulk buying and all 

 

[biffa]

The higher capacity should mean lower internal resistance (in my humble experience).  I hate to say it though there are 11AH cells and 11AH cells.  Cheap normally means not the capacity they claim and higher resistance.

 

[francis]

I was interested in getting a second battery for my Bosch GBH-24. I found batteries that looked just like the original ones, just without bosch on them that were much cheaper than the original ones.

Francis

 

[whitelackington]

Nearly all industrial/building drills are now 36 volt Lithium
I have not heard of anyone buying a new drill for caving over the last year other than these new breed of light weight super drills
but they are expensive  around £600 - £700
with two batteries.

 

[Les W]

Nearly all industrial/building drills are now 36 volt Lithium

This statement is incorrect. 

We have just bought a brand new Bosch 24v sds rotary hammer drill at work and a quick search of the Bosch catalogue shows a vast range of 24v professional quality power tools and I suspect I will find the same at the other main manufacturers.

 

[whitelackington]

Nearly all industrial/building drills are now 36 volt Lithium

This statement is incorrect. 

We have just bought a brand new Bosch 24v sds rotary hammer drill at work and a quick search of the Bosch catalogue shows a vast range of 24v professional quality power tools and I suspect I will find the same at the other main manufacturers.

I
have not heard that any drills other than 36 volt Lithium have been bought for caving over the last year,
you may have heard otherwise.
What I meant was if you are serrious and wealthy, 36 volt Lithium is the way to go,
I have voted with my wallet as did Mister T.Francis,
that is what has been used to get them through to the New Monster Passages in Upper Flood Swallet.


Again spell check will not work.

 

[Leclused]

I would say go for Li-Ion

Our club just bought this one

http://www.hilti.co.uk/holuk/modules/prcat/prca_fuse.jsp?RANGE_OID=29657

And last year we bought the Bosch. Probably the Hilti is better then the bosch but that we will soon known when the hilti is tested underground.


Dagobet (Sc avalon)
www.scavalon.be

 

[nickwilliams]

Li-Ion cells and new drills are a complete red herring in response to my original question.

I have a perfectly good TE 5A 24V drill, (in fact I have two) so I am not about to go out and waste several hundred quid buying a new drill. The Lithium Ion batteries which people are raving about are only rated about 2.4Ah which is fine if all you are doing is drilling holes for bolts or hilti caps, and pretty good when compared with similar sized NiMH or NiCads, but it's not a patch on what can be achieved with an external battery pack (and is needed for serious shotholes).

Even if it's possible to purchase Li-ion cells to make up an external battery pack (and last time I tried, the suppliers were very wary of selling Li-Ion cells in small numbers for the reasons outlined in Andy F's post) it means making a completely new charger and I ain't got the time to design or build one.

So, back to the original question. Has anyone, other than Shotlighter (cheers, Nigel!), got any real-world experience of using NiMH cells for powering hammer drills?

Nick.

 

[Leclused]

We use our li-on machine to drill shotholes from 200 up to 400mm for 8 - 10 mm  diameter, and it works really fine. With two batteries you can work a complete day : drilling, firing, removing debris,drilling,....
But your are right, it's a bit off topic.

Dagobert

 

[Duncan]

I recall using a NiMH pack with a Bosch GBH24VRE drill on CUCC's Austria expeditions several years ago.  The cells were housed in an emptied-out Oldham box.  As far as I know there was no problem with overheating, possibly because the air temperature in the caves is just above 0 celcius.  Unfortunately I don't know any details of the cells used, but perhaps somebody else from CUCC can supply you with that; asking Wookey might be a good starting point - if he doesn't have the information himself, he might have a good idea who to ask.

 

[cucc Paul]

Would like to help you with that one but that doesn't sound like any of the CUCC drills, try Phill or Joel

 

[Duncan]

doesn't sound like any of the CUCC drills, try Phill or Joel

That's because I meant Cambridge UCC, not Cardiff UCC.

 

[Langthwaite Pot]

Hi all,

I'm thinking of using either two of the 12V (3700mAh) battery packs at the bottom of this page, or 3 x 8.4V (4300mAh) with a Hilti TE5a.

http://www.component-shop.co.uk/html/large_packs.html

Can anybody spot any problems? Will it be OK to charge 2/3 packs separately?

Cheers,

George.

 

[digscaves]

Havn't used any NiMH Batteries yet for drills. Prefer to stick with Lead Acid technology, primarily because the charging is easy to arrange and is almost caver proof.

Using a Hilti TE10A 36V/9A a couple of weeks ago we got 3.7metres of 12mm dia hole(these were 850mm holes x 4 plus 300mm x 1)
The battery pack comprises 3 x Yuasa 12v 7Ah cells. Another point to bear in mind is with a bigger pack like this you have to watch the internal temperature of the drill.

If capping with 8mm holes you get fed up around the same time the pack runs out.

Re 24V or 36V, although the batteries are often heavier the drills are more effective (much quicker to drill a given hole).
I would not go back to 24V since using 36V models.

The newer TE6A from Hilti is 36V/12A. I haven't had chance to use one of these underground yet but suspect they will be better than the TE10A (but more expensive!)

 

[Langthwaite Pot]

Hi all,

I'm thinking of using either two of the 12V (3700mAh) battery packs at the bottom of this page, or 3 x 8.4V (4300mAh) with a Hilti TE5a.

http://www.component-shop.co.uk/html/large_packs.html

Can anybody spot any problems? Will it be OK to charge 2/3 packs separately?

Cheers,

George.

A bit off topic, but initial signs look good. 1.5m of 8mm hole and still going strong from one battery pack at the weekend. No problems with overheating so far...

 

[Jopo]

To go back to Nick's posting

Nick wrote:

Has anyone built up an external battery pack of big NiMH batteries for use drilling shot holes with a Bosch or Hilti drill? If so, what did you use and what's been your experience of using it? How do you charge it? Have you got any direct comparison information (e.g. length of hole drilled) with other battery technologies?

I think it is very difficult to make comparisons from different drills/bits/power supplies.
We have been testing Fischer FZEA anchors recently, (still in progress), and it's very clear that modern drills have very much improved hammer actions than my Hilti TE 5-A, regardless of power source, and the choice of bit manufacture is equally as important.
Do not expect the same performance from a cheap bit.

A direct comparison trial might be fun at a Hidden Earth conference. Same rock - same drill bit - different drill.

But if you really want to fly get a decent compressor, loads of bagging and a Sliver Feather with air blast.
Some may remember the trials at Buxton - many moons ago - when we ran a compressor into fire hose over 1k long and ran a full size drill at the end.

Jopo