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[chrisgixer]

Woo...

http://www.ebay.com/itm/Hitachi-WR18DHL-H4-18V-Li-lon-Cordless-High-Torque-Impact-Wrench-Skin-Only/390451382247?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D27%26meid%3D3723293552218855654%26pid%3D100033%26prg%3D1011%26rk%3D1%26rkt%3D4%26sd%3D390451382247%26

[AndyRoid]

The bodies are always cheap Chris, it's the batteries and charger that ramp the cost up.

[chrisgixer]

Wonder what master thinks?

[Marks DTM Calib]

Wonder what master thinks?

As I have said before, the 'memory effect' is down to crap chargers and not a real world issue for good setups (as an example, I have a set of Nicads on my DMU which were originaly fitted to the APT in the early 80's and with good charging, are still going strong).

I have concerns with Li-Ion tech batteries for the DIY user as they are bloody expensive and in reality that extra capacity is not generaly required (and an extra battery pack would easily make up for this and cost less). Plus its a pretty short life battery technology. For 'pro' use with repeated jobs then yes, there is a plus side that can be seen (but again, its at considerable cost).

On the Makita, I have a few Makita items including a NiCad cordless drill, its had heavy use for the past 5+ years and is still going strong and on its original batteries so I personaly rate them very highly (particularly given the price they can be got for). Similarly my angle grinder has a hell of a hard life and is still going (way out living my Dewalt one).

On other types, we have a few cordless metabo's (three off) that get heavy use, all have had new motors plus batteries and one a case (it was dropped) plus one a new trigger/speed control assembly. Parts are easy to get though.

I see no issue with re-celling a battery pack, I have done a fair few, you can work out the type by measuring the external dimensions.

[chrisgixer]

Nice one thanks for the input Mark.

Having emailed the guy in the link re repairs he's decided not to take on the rufurb, due to li ion added circuitry. There's a couple of sensors on this particular pack, having had it apart. I can't see why the 6 solder connections can't be undone and all the electrics lifted onto a new pack. I guess he has his reasons, but the point being li ion does have some extra complications that aren't really necessary for us lot on here.

This is something I've learned since purchasing the hitachi set. I think its a grat set, but would go ni cad next time.

...actually the charger is designed to take any of the cartridge style batteries, so ni cad might be a more suitable replacement.

Anyway, point is, there's options when these bats pack up. Which is good to know. I'll happily continue adding tools to this set. 450nm impact wrench next maybe.


 

[Marks DTM Calib]

I ment to add about the LiIon cells.

There a very complex technology and to ensure they are safe from explosion (over charge one and see what happens!) inside the pack are cell monitors and on most its a circuit board which monitors each individual cell , some also support load balancing etc.

If a single cell starts to go down then the pack will be stopped from charging (Li Ion cells often go short, get one or two shorted cells in a pack and the others see more volts and hence the explosion risk goes up fast!).

The cell failure is stored on a memory device and hence the issue, I am not aware of a way around this (unless you got hold of a non OE battery charger which did not interogate the batterr monitoring circuitry) and there is likely to be multiple devices (the likes of LT, Nat Semi etc do numerous IC's for this)

[chrisgixer]

So it's worth replacing early? Before the circuit board sees a fault? Both batteries are fine, but not sure if it's the same one, every now and then I plug one into the charger and it refuses to charge and the led blinks continuously signifying a fault.

The way round this is to plug the other battery in, get the charger running then swap the other "bad" battety back in. All is then fine.

Repair guy recond it was a duf sensor. The connector tabs on the battries are clean. So good contact seems likely. There's actually 6 contacts on the battery male end that plugs in

[Marks DTM Calib]

Me thinks your repair guy is over simplifying it.

There will be an internal temperature sensor but I susepct the fault will be a failing/failed cell.

Also be wary as you need the same cell type (not just size), quite a few of the aftermarket ones are based around laptop tech which are not fast charge/high discharge tolerant.

[hoofing it]

Another thought, are there better cells I could use?

Best cells to use is a truck battery(s)12-24v.
Here's how. The auto spark at my work bought a brand new top of the range snap-on impact driver minus the i-on battery (18 volt)for £50.00 from the snap-on rep he then attached a 6 metre flex to the terminals inside the gun and put clips on the other end and all he has to do is connect it to either 12 or 24 volt set up (truck,bus or van etc).
When I asked him how it worked he said great best £50 he ever spent he said that because it's 18v and has a forward reverse function on it,it doesn't matter how you connect it to the battery and you get away with running it on 12v or 24v. This also works with normal battery drills and he recommends only doing it on a 18v or more drill.   

[Marks DTM Calib]

Hes bloody lucky its still working sticking 24V plus through an 18V motor......as that poor motor is running at double the wattage.

[Taxi_Driver]

I ment to add about the LiIon cells.

There a very complex technology and to ensure they are safe from explosion (over charge one and see what happens!) inside the pack are cell monitors and on most its a circuit board which monitors each individual cell , some also support load balancing etc.

If a single cell starts to go down then the pack will be stopped from charging (Li Ion cells often go short, get one or two shorted cells in a pack and the others see more volts and hence the explosion risk goes up fast!).

The cell failure is stored on a memory device and hence the issue, I am not aware of a way around this (unless you got hold of a non OE battery charger which did not interogate the batterr monitoring circuitry) and there is likely to be multiple devices (the likes of LT, Nat Semi etc do numerous IC's for this)

I have a couple of Li on's that wont charge (could be just the one tho.....as charged in pairs)
As far as i can see....the charger for them charges them to 4.2v (they are TR18650's 3.7v 3800mAh) after 3-4hrs they reach the 4.2v and the charger says done.....however put them in a 3800 lumen torch and they give up after 5 mins.....i carnt see how the charger monitors the pcb inside batteries  as they are just like AA batteries, except bigger.....

[Kevin Wood]

I ment to add about the LiIon cells.

There a very complex technology and to ensure they are safe from explosion (over charge one and see what happens!) inside the pack are cell monitors and on most its a circuit board which monitors each individual cell , some also support load balancing etc.

If a single cell starts to go down then the pack will be stopped from charging (Li Ion cells often go short, get one or two shorted cells in a pack and the others see more volts and hence the explosion risk goes up fast!).

The cell failure is stored on a memory device and hence the issue, I am not aware of a way around this (unless you got hold of a non OE battery charger which did not interogate the batterr monitoring circuitry) and there is likely to be multiple devices (the likes of LT, Nat Semi etc do numerous IC's for this)

I have a couple of Li on's that wont charge (could be just the one tho.....as charged in pairs)
As far as i can see....the charger for them charges them to 4.2v (they are TR18650's 3.7v 3800mAh) after 3-4hrs they reach the 4.2v and the charger says done.....however put them in a 3800 lumen torch and they give up after 5 mins.....i carnt see how the charger monitors the pcb inside batteries  as they are just like AA batteries, except bigger.....

3.7V is just a single cell, so no problems with charging other than monitoring the cell terminal voltage, which can be done across the normal terminals. Put a few cells in series and you now have a monitoring problem. They still do quite often have an extra pin to a temperature sensor or smart chip, though.

[chrisgixer]

Pic of sensors, in between cells on the left is the white thing with two white wires.

[chrisgixer]

...and the board. I guess they don't want anyone getting in there, going by that black stuff painted all over it.

[Taxi_Driver]

I ment to add about the LiIon cells.

There a very complex technology and to ensure they are safe from explosion (over charge one and see what happens!) inside the pack are cell monitors and on most its a circuit board which monitors each individual cell , some also support load balancing etc.

If a single cell starts to go down then the pack will be stopped from charging (Li Ion cells often go short, get one or two shorted cells in a pack and the others see more volts and hence the explosion risk goes up fast!).

The cell failure is stored on a memory device and hence the issue, I am not aware of a way around this (unless you got hold of a non OE battery charger which did not interogate the batterr monitoring circuitry) and there is likely to be multiple devices (the likes of LT, Nat Semi etc do numerous IC's for this)

I have a couple of Li on's that wont charge (could be just the one tho.....as charged in pairs)
As far as i can see....the charger for them charges them to 4.2v (they are TR18650's 3.7v 3800mAh) after 3-4hrs they reach the 4.2v and the charger says done.....however put them in a 3800 lumen torch and they give up after 5 mins.....i carnt see how the charger monitors the pcb inside batteries  as they are just like AA batteries, except bigger.....

3.7V is just a single cell, so no problems with charging other than monitoring the cell terminal voltage, which can be done across the normal terminals. Put a few cells in series and you now have a monitoring problem. They still do quite often have an extra pin to a temperature sensor or smart chip, though.

Ah right, thanks