Hi, I have a lot of DeWalt tools and am based in the UK. I was having particular problems with my
circular saws which are particularly demanding on batteries. My plunge saw was the most frustrating
when it stopped part way through a cut
Because of this I found a solution to providing mains power - - - - - 18v circular saws can draw
22Amps at peak.
If you're willing to do a bit of DIY on the set up and can do or know someone good at soldering then you
should be able to do it for less than $120.
You will need a heavy duty soldering iron, I was struggling (but successful) using a 170Watt pistol grip
style iron. If you can get hold of some liquid solder flux it would make the job much easier, without is
quite a struggle but still possible depending on your skill.
For approx $100 including shipping you can get the same power supply (PSU) I use from eBay, you're
looking for:
500W 18V 28A Switching Power Supply With Current Control Charger (says it's for CCTV but works
fine for me)
You will also need:
1. Standard mains lead flex of a suitable length that can handle a decent amount of current e.g. 16Amps
or more.
2. Standard flex lead that can easily handle 18v 30Amps or preferably more (keep this short, e.g. 2m
max or you will suffer too much volt drop on the lead) (I initially used too lightweight a cable and too long
and it didn't work)
Note: If you expect to use it in cold conditions use "arctic" cable
3. Cord/flex support grip for where flex passes through battery housing
4. Scrap DeWalt battery (or any other suitable make)
5. Very dense foam to fill void left by removed cells
6. Ideally a box of some sort (with ventilation) to protect PSU and its connections from damage
Procedure:
1. Dismantle scrap battery, remove all cells BUT keep the one closest to output terminals (cut away
other cells as necessary).
2. Desolder wire lead to positive at terminal connection
3. Drill hole in convenient place in battery for flex to pass through using flex grip/support allowing for
routing of cable internally
4. Strip back wiring and solder positive lead to positive terminal
5. Rough up exterior of battery cell close to the bottom (or cable will foul in housing)
6. Tin the connection point before trying to solder on wire and tin the wire
7. Whilst there is still heat in the battery apply liquid flux to battery and solder wire to battery keeping wire as flat to battery to avoid fouling on reassembly (as mentioned it can be tricky but make sure it is a good joint as it has to handle a lot of current)
8. Connect cables to appropriate terminals of PSU (make sure to link all similar voltage polarity terminals together to get full current capability)
9. Cut some foam to fill void in battery casing, you're looking to make sure battery with connections on stays up in it's correct position so you get good contact with the tool.
If you don't need such high current e.g. only for a drill then select a lower rated PSU from eBay and you can downrate cabling as appropriate and save money.
Needless to say you do this modification and use it at your own risk
Hope this helps
