Question about Hilti Cordless Hammer Drill Sfh 151 A 2.0Ah

1 Answer

Battery pack failure

Wickes 18 volt battery pack, would not charge. Have investigated the cells and found what looks like a disintegrated resistor in the wire connectors, taped to the adjacent cell. Does anyone know the identity and rating of this component as a replacement would solve my problem.

Posted by on

  • 1 more comment 
  • stephanie773 Apr 20, 2009

    Thanks, but I don't think it is a thermal fuse;there are no 'remains' which I would expect to find from this type of component. It seems to relate to the charger which has two lights; Red when charging and green when charged. If I link the wires across where the component has failed I get the green 'charged' light so I guess what it should do is modify the current flow as the charge cycle completes.

  • stephanie773 Apr 21, 2009

    Thanks for the info, I shall try charging with the wires linked just to see if it takes the charge OK . The only concern I have is the green 'charged' indicator light which is permanently lit on the charger unit.

  • stephanie773 Apr 22, 2009

    Charger is fine; I borrowed a battery from a colleague to check it out. Will get around to checking individual cells after I return from a trip to Spain. Thanks for all the good ideas and assistance.

×

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Master
  • 5,568 Answers

The device you found isn't likely a resistor but a thermal fuse. These are incorporated to open at a fixed temperature to prevent cell explosions if the charger fails or cells are shorted exposing the remaining good cells to either too high of a current or overcharging. These fuses do not heal, once open, they are finished.  

If you are in the US, you can buy a low-cost digital multimeter that will let you check the individual cells; nominal for NiCad is ~ 1.25-1.4  volts after charge or about the same for NiMh cells. Any cell 10% more or less after charging is not normal. It will also let you check the continuity of the thermal fuse and this should show up as a nearly dead short - 0 Ohms.
You can buy such meters at Radio Shack or auto parts stores for under $20 and under $10 if you have a Harbor Freight Tool store in your area.  

Posted on Apr 19, 2009

  • Steve Allison
    Steve Allison Apr 21, 2009

    If I link the wires across where the component has failed I get the green 'charged' light so I guess what it should do is modify the current flow as the charge cycle completes.


    I have to disagree; the thermal fuses are generally in a 'bullet-shaped' metal tube with one end common to the case, the other insulated.
    I don't think there are any chargers made anymore that have simple current limiting to protect batteries since that doesn't work well. NiCads, NiMh both have a measureable charge characteristic that is used to drop the charge current down to a low level once a certain point on their particular voltage rise is reached.


    Shorting across that part, regardless of its nature is probably quite safe but I wouldn't leave it charging while absent; without the protection, a failure of the charger could cause cells to burst.    

  • Steve Allison
    Steve Allison Apr 21, 2009

    It would help if you had a meter at hand to verify the condition of both the battery pack and the charger for this reason:
    - The charger itself may be faulty if the green LED is permanently on. The circuit in the charger monitors the voltage rise and then switches from red to green once the terminal voltage of the battery pack drops off a minute amount; all rechargeables with which I am familiar react much the same way.
    They receive a controlled charge current (which can be constant or pulsed) and this causes the voltage of the pack (or cell) to rise but eventually 'fold back' once they have reached full charge. 
    The fast-charge type of charger actually slaps a heavy current into the battery, then reverses the pulse polarity and discharges at a rate of 10-15% of the charge current. For reasons of physics I am not cognizant of, this prevents the buildup of heat and gases that normally accompanies a high current charge.


    Having a meter available would also allow you to locate cells that are defective (they will show little or no voltage at all) and even replace them if you have some manual skills and a good quality soldering iron or station.
    I've retrieved many of my packs from the dead this way.
    Unfortunately, a failed charger can destroy a good battery and the reverse is true too.

×

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

I need to know what the output needs to be on the charger of an 18 volt jobmate cordless drill.


During the initial state of the charge, the charger operates in a fixed-current mode. This means that the current will be held at a constant rate until the battery is charged to a bit over 18 Volts. During this phase, the output of the charger will not be 18 Volts. This is done for safety and battery preservation; forcing 18 Volts on a battery discharged down to 15 Volts or less could cause the battery to overheat. If no battery is connected, the charge controller may hold the output low until a battery insertion is detected.

The exact behavior of the charger depends on the chemistry for which it is designed, whether Nickel-Cadmium, Nickel-Metal Hydride, or Lithium ion. If the output of a known-good battery is 18 Volts after charging, and it has normal capacity, the charger is working properly.

However, a bad cell in the battery changes things. If you run a Ni-Cd battery down too far, the weakest cell in the battery may begin to reverse charge from the current coming from the other cells. This usually causes an internal short circuit, and the cell will be stuck at 0 Volts. A battery pack with one shorted cell will read 16.7 -16.9 Volts when fully charged, and the drill will not have the peak power it should. The charger will give you a battery fault indication if it is equipped to do so.

Jul 08, 2017 | Drills

2 Answers

Dyson will not start


If the power cells are operational and it will not start; then either the motor is dysfunctional or something is jammed in the intake module. A conduction test with instrumentation can indicate if the motor is the problem, the power cells are not fully charged, or you have a short circuit. Check Fuses.

Feb 26, 2014 | Dyson DC44 Animal Digital Slim Cordless...

1 Answer

My 18 volt worx battery will not hold a charge


A lot of ni-cad packs have one or two bad cells. to find the bad one(s); unscrew the cover on the battery pack and use a voltmeter set on dc volt 2v full scale and test the cells one at a time. they should each have at least 1.25 volts. The bad cells can be removed and replaced with good cells from other discarded packs. If they're not too old many ni-cad cells will still work. You can also revive some cells by unplugging the vent hole in the top of the cell so it can breathe (seriously). Also, I have zapped single cells by momentarily connecting them one by one (even in the pack) to a car battery. plus to plus,minus to minus. But only for about a half second. Also, heating ni-cads will kill them.

Dec 22, 2012 | Worx Ni-Cad Replacement Battery, 18 Volt

1 Answer

How long should a fully charge battery last on WG250E Hedge Trimmer


This is the info i found on WG250 battery . It says up to 50 min below in the features. Hope it helps

Battery
The WORX WG250 hedge trimmer incorporates an 18-volt 1.7 Ah Ni-Cd battery pack. You can use this battery pack with other WORX Ni-CD PowerShare tools. The included charger takes about an hour to restore a dead battery to full charge.


Cordless Hedge Trimmer 18v Worx WG250E jQuery(document).ready(function($) { $("a[rel=product-image-gallery]").fancybox( { 'transitionIn' : 'elastic', 'transitionOut' : 'elastic', 'titlePosition' : 'over', 'titleFormat' : function(title, currentArray, currentIndex, currentOpts) { return 'Image ' + (currentIndex + 1) + ' / ' + currentArray.length + ' ' + title + ''; } }); });

dsc_9515.jpg
Features


  • Wall mount bracket
  • 3 position adjustable front handle
  • overmould soft grip for user comfort
  • Quick release handle
  • Double insulated
  • Volts: 18
  • Blade length: 510mm
  • Cutting capacity: 14mm
  • Blade action: Dual
  • Run time: Up to 50mins per charge
  • Charge time: Up to 1 hour
  • Machine weight: 3.1Kg
  • Comes with one battery and a charger

Sep 13, 2011 | Worx Wg250 20inch 18volt Cordless Hedge...

1 Answer

Wont charge


Probably the battery pack is worn out or has a "memory" problem. A worn out pack will have one or more cells shorted internally (one or more cells read 0 Volts, and an ohmmeter reads less than 1 Ohm when connected to the 0 Volt cell). If it is a memory problem, it is possible to recondition it, but not simple. You have to remove the pack, then connect a 150 Ohm resistor across each cell and let the battery sit until the cells are completely discharged. You can't just connect a resistor across the entire battery pack because the stronger cells will reverse-charge the weaker ones, which will cause them to short out.

Running the battery too far down will cause the reverse-charge problem, but not running it down at least occasionally will cause the memory problem. (Memory problem explained: the cadmium crystals grow when the battery is charged and shrink as it is discharged. However, the larger ones tend to remain intact on discharge and grow faster than the smaller ones. Eventually they block the ion flow through the battery, so the battery loses capacity. It's called a memory effect because the battery only "remembers" it has the capacity to go down as far as it is habitually used. Running the cell all the way down dissolves the over-sized crystals.)

It is possible you have a problem with the charger. Check for voltage on the charger plug. It should be about the rated output voltage printed on the charger box before messing with the battery.

Apr 23, 2011 | Dirt Devil BD20035 Bagless Stick Vacuum

1 Answer

Milwaukee tool 18 volt nimh battery won!t charge


If the battery pack is more than 2 years old its time for a replacement. The typical charge/discharge life cycle of a rechargeable cell is 500 - 700 times and the shelf life is about 3-4 years from the date of manufacture. If the charging indicator lights up when you dock the battery on to the base and still does not work after 5 hours - its due for a replacement.

Apr 08, 2011 | Dewalt Accessories Batteries 18 Volt

1 Answer

Need Bissel 1715 wiring schematic. Charging circuit has burnt resistor. Need to know resistor details.


Can not believe NO ONE could answer this.

The R1 resistor basically drops the 9V to around 5V for charging the battery pack. The resistor is a 10 ohm , 2 watt resistor. The other resistor is 220 ohm. This only limits the current to the LED.

The 10 ohm resistor burnt because the battery pack was left to sit too long without use and charging. So the cells shorted causing excessive current through the resistor when you attempted to charge the batteries.

After replacing the resistor, you will need to replace the battery pack before charging. Otherwise, you'll just burn the resistor again.

Sep 27, 2010 | Bissell 1715-G Spotlifter Bagless Handheld...

1 Answer

The PCB controlling the battery charger is overheating and the led dosen't illuminate when charging, could the led be shorted internally causing the problem. The vacuum in question is a Hoover Freejet...


The problem was caused by the failure of 7 of the 1.2volt cells in the battery pack, the other problems were symptoms of the battery pack failure. Replaced the thermal cutout a 131 degree C component on the PCB in the docking station for the vacuum when recharging, I also had to change the LED which had also failed this is a Red 12 volt 5 mm dia component observe the correct polarity when replacing. Also make sure when replacing the thermal cutout that it is secured tightly to the resistor it sits along side, otherwise it will not respond quick enough if there is another failure.

Jun 22, 2008 | Vacuums

2 Answers

Sharp Camcorder VL-NZ100E battery doesn't seem to charge


2.7 volts is too low. Usually camcorders use battery at least 6 volts. Problems with rechargeables especially NiCds and NiMH, a cell will be shorted. for 6 volts pack, there are 5 cells in series (5 pcs x 1.2 volts with load , 1.35 no load). If you are measuring only 2.7 volts, it is highly possible that 3 cells are dead. As for the charger, if the same charger is used to power the camcorder and you said the the camcorder operates using the adaptor, this means that the charger is OK. You can ZAP the battery back to life but I will not recommend. It can be dangerous. If you can buy the battery, I suggest you do it since the old battery, even when zapped, will not provide enough juice anymore.

May 22, 2007 | Sharp Viewcam VL-NZ100U Mini DV Digital...

Not finding what you are looking for?
Hilti Cordless Hammer Drill Sfh 151 A 2.0Ah Logo

551 people viewed this question

Ask a Question

Usually answered in minutes!

Top Hilti Drills Experts

Doctor PC
Doctor PC

Level 3 Expert

7733 Answers

woodzowl307

Level 3 Expert

652 Answers

John Trevino

Level 3 Expert

1388 Answers

Are you a Hilti Drill Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...