Using 18V DeWalt Battery with 14.4V Tool

[Joelk]

Has anyone done this?

If so, what were the results?

How long did the tool last?

 

[shoot summ]

The 18v battery wont fit in the 14.4 tool(I just tried it).

 

[Joelk]

It will if some modifications are made to the 14.4V Tool.

 

[scarney1988]

My 18v dewalt charger will charge a range of packs from dewalt (so the label says). I used jumper wires to charge various 12v packs from B&D and Skil. In short, I have had success charging non-18v Dewalt packs (as long as they are nicad) with my 18V dewalt XRP charger.

Good luck.
sean

 

[Joelk]

I want to use 18V DeWalt Batteries in my 14.4V DeWalt Tools.

I have several 14.4V DeWalt Tools, but all of my 14.4 V Batteries are now bad. I don't plan to buy more so I am probably going to modify the tools so that I can use my 18V Batteries in them.

I have modified one of the 14.4V Tools and the 18V Battery now plugs in(I am using a bungee to hold it in place) and runs the tool.

The tool seems to run normally, just faster than it did with a 14.4V Battery. It does not seem to be overheating or anything, but I have only run it for a few seconds(with no load) so far, so I don't know the long term effects.

 

[Joelk]

Anyone?

 

[Mickey O]

It's illegal, punishable with up 5 years in jail and a $2000 fine, don't do it.



I don't see a huge problem with doing it (keeping in mind that the motor was most likely designed for lower voltage and might burn out prematurely) other than having bungee cords on your tools. I'd just get a new cordless set or rebuild the 14.4 volt batteries.

 

[Joelk]

I just thought I would provide an update in case someone else might consider doing this.

I have used the 14.4V impact wrench with the 18V battery several times now and so far so good. It runs faster and seems to have more power than when run on 14.4V. No signs of overheating or other issues.

I am holding the battery onto the tool with some 1/8" shock cord(bungee cord material) and it works very well. It is small enough that it still lets the tool stand up by setting it down on the battery.

 

[AV tinker er]

As this isn't as severe as plugging say a 110 vacuum into a 220 line (it will work really well for a few seconds) you will burn up the components prematurely (as previously stated). The batteries should last linger per charge though, so you have that going for you.

 

[firebox40dash5]

It's illegal, punishable with up 5 years in jail and a $2000 fine, don't do it.



I don't see a huge problem with doing it (keeping in mind that the motor was most likely designed for lower voltage and might burn out prematurely) other than having bungee cords on your tools. I'd just get a new cordless set or rebuild the 14.4 volt batteries.

I modded a friend's kids' Power Wheels with a 530-size RC motor and a Makita LXT battery. I think the original motor was rated for something right around 12v, the new one IIRC was about 14.4v, and both motors lasted longer than all the parts after it. That thing would pop a wheelie without a kid on it, or break a gear with one.

I wouldn't doubt, as old as those designs are, that the lower-voltage tools are still able to take the voltage of the 18v battery. What I remember from looking for RC motors was motors made for pretty wide voltage ranges. Not to say that B&D couldn't or didn't spec their own motor, but it seems plausible they'd either use an off the shelf motor and/or use one motor for more than one voltage to reduce inventory and get a better deal.

 

[Joelk]

Just an FYI.

It has been over 3 years since I converted the tool and it is still going strong.

It is stronger/faster than at 14.4V and no signs of impending failure.

If I ever find Dewalt 18V - 20V Max adapters cheap, I will probably permanently mount one on it and go to newer 20V Batteries as my supply of 18V batteries is now getting low.

 

[gdocktor3]

Wow that's surprising

 

[Provincial]

Not DeWalt, but Hitachi. The 14V tools have a lug cast into the battery guide slot that I removed with a wood chisel. Then the 18V batteries slipped right in. I did this to two drills and they work well on 18V. I don't notice a difference in power, but the batteries have twice the amp/hours so they last much longer. I notice a little more ozone smell when they work hard, but I've been using them for four years now with no ill effect.

P.S. I have recently added Lithium and Ni-Mh batteries to my NiCads with no difference in performance of the drills other than related to the batteries themselves.

 

[Joelk]

Well the day of the cheap(<$15) 18-20V adapters has arrived.

I bought one from Waitley and attached it to the bottom of a 14.4V tool with a sheet metal screw.

It seems to be secure and working great.

If anyone knows of an adapter that is even better(better price or better quality for similar/lower price) than the Waitley version, please let me know. I have other 14.4 tools that I will probably convert now that cheap adapters are available.

 

[Grimly]

It's interesting to read of the longevity of 14.4V tools on 18V. I'm in the same position - I have several good old Makitas that normally take Ni-Cads and NiMHs of 14.4V, but I also have a universal charger that will charge 18V Makita Li-Ions, so I've been wondering for some time if it's worth the risk... an adapter for the physical fitment is easily available, for around 25 quid on ebay, but the adpater is intended for the use of Makita 14V Li-Ions on older tools. However, I'm fairly sure the 18V batteries will slot in.
If I try this and the smoke stays in, there's a lot of useful life left in these tools. Might be a bit shorter life, but nothing ventured, nothing gained.

 

[Technophiliac]

Just an FYI.

It has been over 3 years since I converted the tool and it is still going strong.

It is stronger/faster than at 14.4V and no signs of impending failure.

If I ever find Dewalt 18V - 20V Max adapters cheap, I will probably permanently mount one on it and go to newer 20V Batteries as my supply of 18V batteries is now getting low.

Just found your thread, much appreciated thank you as I am considering doing similar, in my case with a 15.6V Metabo Drill using AEG 18V Li-ion Batteries.

I Figure the motors / electronics are over engineered to cover repeated stalled drill scenarios (Max Load Drawn then) so a little jump in voltage will give more power and cause more current drain, however I reckon it will be safe until one repeatedly maxes out the drill - when risk of motor / electronics burn out will increase. Your experience supports that view, perhaps you can comment on how heavily you have used your 14.4V drill / 18V Battery combo?

In my case I am considering using an old Metabo Battery case with the defunct battery stalk cut off and gluing and screwing an AEG USB Adapter to the Metabo Battery stalk to essentially make my own battery adapter between the old style Metabo Battery and New AEG Lithium cells.

 

[Joelk]

I really have not used any of my converted 14.4 Dewalt tools for a lot of high exertions activities, but they continue to perform just fine.

 

[rsanter]

Look on Eparts for the part number of the motors in the 14 and 18 volt version. It may be the same motor and different gears that set the RPM.

I used to work for B&D and years ago on a previous line of their cordless tools I converted them by buying the replacement housing for the higher voltage tools and installing that.
I was able to reuse the motor,gearbox,switch, wiring...all of it and just changed the plastic housing. Used it for years with no problems

 

[Bacon!]

^ Same motor seems unlikely, but it might matter what generation it was. My 14.4V Dewalt (DW991, IIRC they weren't making 18V at the time.. but I could be wrong) is very strong for a 14.4V, must have used a higher current motor to get there.

There's no way that any 18V drill operating at 14.4V would have as much power, I notice that easily when my 18V drill batteries drop voltage that much. If it just used faster gearing to achieve similar RPM then it wouldn't have the torque it does. I expect it would burn out at 18V if under a high load.

For example, suppose your motor has avg (at high load) 0.9 ohms at 14.4V so 16A or 230W. Now at 18V, that's 20A or 360W, overdriving it by about 57% which is a lot. It might be down closer to 50% because you'd have higher cell voltage sag/depression at the higher current.

This will mostly be a factor when it is bogged down, because then the fan in the motor is spinning slower, and the motor is pulling more current.

 

[jgromada]

I am wondering if everything you are talking about is are NiCd batteries?

I have kind of lost interest in NiCd but i have modified some tools to operate with LiOn batteris. I had a really small saw from Makita 9.6 v 3.5 in. It works but i am looking for an appropriate battery management system(BMS) . Right now i can't use it for long because i don't want my 12v Milwaukee cells to get to too low a voltage.

 

[Joelk]

I am wondering if everything you are talking about is are NiCd batteries?

If you are referring to me, I started the thread before the 20V Max batteries were the norm and I used the 18V NiCads, for quite a while. I now use a "permanently attached" 20V-18V adaptor and use the 20V Max batteries.

 

[Technophiliac]

^

There's no way that any 18V drill operating at 14.4V would have as much power, I notice that easily when my 18V drill batteries drop voltage that much. If it just used faster gearing to achieve similar RPM then it wouldn't have the torque it does. I expect it would burn out at 18V if under a high load.

Hey Bacon many thanks for jumping in. I agree with all you've noted except the bit I've quoted, can you confirm you have said what you intended to say, because this thread is about higher voltage batteries for lower stated voltage tools.

Also commenting on the battery type, in overview, the battery type is relevant to the extent each type of battery has different characteristics, I do not wish to set all that out, beyond observing the voltage is the voltage where-ever it comes from, but secondly the ability of the power source to maintain that voltage under increasing load is IMO highly relevant. Which in writing this makes me realise where we are over volting a tool there may be some advantage (that is risk reduction) in using the LOWER power pack versions, that is a 2 A hr 18V battery has less capability of damaging a tool than a say 6 A hr 18V pack which under load will pump more current and tend to maintain the voltage, the power, the wattage and the heat going through the tool, which is usually what kills parts - too much heat in the wrong places...

Also I would make clear that the charger for any over volt battery will need to match that pack, and not generally be the original tool's charger, unless the original charger covers the higher volt cell as well, for example my Metabo ICS 10 charger charges NI-cd and NiMH to 18V but not Li-ion batteries so it could not be used for the AEG batteries I was considering but could be used for a NiMH 18 battery pack.

As has been suggested I searched for information on my motor type and cannot verify it is also used in 18V drills. Also the electronics in my drill uses the "impuls" electronic pulse technology and again seems limited in use to the 12 and 15.6V versions of my drill. If I fry the tool through overvolting that will really kill the tool with availability of replacement parts difficult at best. Therefore I've decided given the special case of this drill I am better to just replace the existing cells with NiMH batteries. The impuls function works well so I wish to preserve that drill so hereon I will "baby it" to more lighter and special duties.

My decision should not stop others over volting non impuls drills especially where replacement parts are available and or confirmation the motors are in any event designed for the higher voltages.

 

[Bacon!]

^ It seems like you are heavy on words and short on understanding. There is very little "pump more current", it is purely a function of the battery voltage.

As I already stated, I think my 14.4V would burn up if put under heavy load at 18V, but if you (or I) operated it at lesser load at 18V, it would survive. It's not life or death so if you've got one lying around and are dying to experiment, why not?

Even so, there are many ways to skin a cat. Dewalt batteries are notably expensive so they don't seem to be the most cost effective way to arrive at a solution unless you already have them. Either way, you can monitor the tool and heat under your most demanding use.

It's not like this is a heart monitor, your tool, your gamble, in some cases it will work.

 

[Technophiliac]

^ It seems like you are heavy on words and short on understanding. There is very little "pump more current", it is purely a function of the battery voltage.

As I already stated, I think my 14.4V would burn up if put under heavy load....

Hmmm your next quoted sentence contradicts your first sentence - does it not?

As you note "heavy load" determines current..... pump more current....

Using your own words I reject the assertion I am short on understanding.

 

[Bacon!]

^ Using a lower mAh pack won't matter that much. There is going to be more voltage depression on a pack using a single series of cells, if the higher capacity pack had two more more paralleled series, which it necessarily would with current tech making it impossible to achieve 6Ah with only a single series, but the resultant voltage will still be substantially higher because the cells chosen are designed for high current.

Further, back in the 14.4V era, packs were practically never designed with paralleled series of cells, so this droop was already accounted for and a higher current motor sized with that in mind to achieve the target performance level.

If you had that concept in mind then I misread your post, but otherwise we'll have to be content to disagree.

 

[jayemm]

If you were ever to look up the specs for the motor by researching the manufacturers website- Johnson and Mabuchi are two popular manufacturers- you would find these DC motors have a voltage range,sometimes quite wide.Your 14.4 V drill may have a motor with a range from 12v to 25 v for example.The part number is stamped on the side of the motor.These spec sheets usually also give torque and current and efficiency curves on a graph.I 'd run 18v in a 14.4 drill.As others said,more power.

 

[Technophiliac]

By chance I took a reading from a 15.6V Metabo clone Nicad fresh from the Metabo 4.8 to 18 Volts charger. Wow! 19.0 Volts! This is an old nicad near the end of its life - that is it is short on puff and staying power! Puts a whole new perspective on things for me!

The tool must have been designed to cope with that starting voltage, so using an 18V pack should really be of little concern.

However we must be mindful a 18V 6.0 Ahr AEG Li-ion pack straight off the AEG charger reads, as I have just done, 20.17 Volts!

{I understand this evidence the marketing speak of 20V batteries which I understand to just represent the fully charged 18V pack to claim some advantage which I am not sure exists}

 

[retDAC]

I am wondering if everything you are talking about is are NiCd batteries?

If you are referring to me, I started the thread before the 20V Max batteries were the norm and I used the 18V NiCads, for quite a while. I now use a "permanently attached" 20V-18V adaptor and use the 20V Max batteries.

Thank you so much for the followups! Wish everybody did that.

 

[David1811]

A bit late to the game here, but about 15 years ago I bought a DeWalt 14.4v combo tool set. I find the 5-3/8” trim saw (DW935) to be extremely useful as it’s light and left-bladed (I‘m right handed). Anyway, my NiCad batteries started dying out and I wasn‘t too keen on investing into any more XRP batteries, especially since I had for the most part moved on to the Makita LXT system (18v) after a few years.

However I found myself in a position where I needed to make a ton of half-lap and cross-lap cuts in a lot of pressure treated 4x4’s and I really needed that saw. I charged up the old XRP batteries and literally was getting three to five cuts before each battery died.

After a bit of searching, I found an adapter on Amazon which would adapt LXT batteries to the DeWalt XRP tools but only at 18v. I bought one, and was determined to make it work. After a bit of grinding away (at
the adapter, not the tool), I got it to fit snug. I then mounted the adapter to the DW935 with a screw and now use 18v LXT batteries on my 14.4v saw. The saw runs faster and has more power. So far I’ve not experienced any problems and there’re no indications that it’s about to give up the ghost running at the higher voltage. The adapter also worked with the 14.4v drill, recip saw, and work light, but it was the trim saw that I used most heavily.

Based on my experience, I’d say it’s fine to run DeWalt’s 14.4 tools at 18v (at least the trim saw for sure ). Logically, tool longevity might suffer down the road, but my XRP tools weren’t seeing much use otherwise anyway and it’s nice to breathe some new life back into them.

 

[johninct]

My Snap-On 14V batteries died so I have been using my 18V batteries. They have more power but spark more.