Modular tool battery charger wall

Several people have made wall-mounted cordless power tool battery charging stations, but none so far has been modular, and most so far have been pretty small because most people don't have tools of many brands. Also, none so far has incorporated any cooling or advanced power management features.

At Protospace we have cordless power tools of several brands. These all of course have their own proprietary batteries, which all of course have their own proprietary chargers. Up to now we've just had a tall, narrow shelf unit with the chargers and batteries piled on its 3 tiny shelves, one of which is at floor level. This is really clunky, so I want to wall-mount the chargers. For now I'm just going to screw/strap the ones we actually use to a board and screw that to the wall, probably without even offsetting it and running the power cords behind it. But what I really want is something like the following:

Each tool battery charger is mounted on a small plywood pallet of standardized size. Some pallets are multiples of the standard size, to accommodate larger chargers. The pallets can mount vertically (i.e. with their plywood parallel to the wall) on the frame, which is mounted to the wall, to assemble a two- dimensional array of chargers. Each pallet has the screws or straps appropriate to hold the charger to be mounted on it, as well as an appropriately placed hole for the power cord, so the cords can be hidden in the back. Each pallet can also have a printed and laminated piece of paper, or other signage, affixed to its face underneath or beside the charger. (Other signage options would include laser marking, hand woodburning, writing with a marker, etc., but printed and laminated paper looks pretty good and is accessible to just about everyone.) The pallets mount to the frame with some mechanism that locks them in place, so that they don't risk falling off of the frame when you apply the force necessary to slide a tight battery upwardly or forwardly off of a charger, as would be the case with e.g. French cleat mounting. (The locking mechanism could be something simple like the lock peg used in pallet racking, or a whole-rack-at-once lock/unlock lever mechanism…)

Once you've mounted the chargers to the pallets, you can mount the pallets to the frame in any arrangement you like, and rearrange them whenever you want. For example, I want the ones at Protospace to be alphabetized by brand name, so it's easy to find the one you need even though you probably don't use the shop every day. When we get a new one or get rid of an old one, we'll can* rearrange the chargers to maintain alphabeticity** without having to unscrew, rescrew, move straps, make new holes for cords, etc., and we'll don't* end up with a board with a bunch of ugly holes all over it from old arrangements.

Over the front of the frame, set sufficiently far forward to avoid hitting any batteries on the chargers, is either a clear door that can be closed between accessing the chargers or a set of transparent flexible plastic flaps hanging from the top that move out of the way as you reach between them. The purpose of this is to keep the air inside the charger frame separate from that outside. At the bottom of the frame is an air filtration unit, providing clean air into the charger frame. This is to cool the batteries and chargers and keep them clean, and the warm air flows out the top (which is provided with a cover like a chimney-top to keep out dust when the fan isn't running). These air handling features provide a nice environment for the chargers and batteries so they last longer and so they don't have to spend as long cooling before charging can begin, especially those battery/charger systems that use forced air flowing through the battery itself to cool the battery before charging. (We don't have any of those yet, but we probably will soon.)

Another feature is the switching system. A tool battery charger and battery left plugged in unattended can pose a small but nonzero fire hazard, especially if they are old and/or in a dusty environment. Therefore, to avoid having to unplug the chargers or turn off the power strip manually, there's a switching system that consists of: an individual relay for the outlet into which each charger is plugged, a button on each pallet to activate the mounted charger (with an indicator light next to it), and a timing device that keeps track of how long each charger has been on and turns each one off after a programmed time interval.

(It would also be possible to monitor the current being drawn by each charger and turn them off after they stop drawing much current, but it would be hard to get that to work properly for each charger model, and that would still allow a charger to remain on indefinitely if it never stopped drawing current due to a fault. On the other hand, that approach would be able to mitigate the shortcoming of the button-and-timer system that it will turn off a charger partway through the charging of a second battery if you swap batteries after the first one is charged but don't repress the button. But that could also be solved by flashing the indicator light next to the button during the latter half of the timer's interval, to remind you to press the button again if you're swapping batteries.)

Finally, at the bottom, there are shelves for batteries. At Protospace, I'm imagining there being three: dead batteries waiting for open chargers, full batteries waiting to be used, and bad batteries waiting to be repaired or salvaged. Maybe a fourth to store battery adapters to use batteries and tools from different brands together, if we get around to making any of those. Also, since some tool battery chargers have USB ports, there could be a phone shelf to put your phone on when charging it from one of said USB ports—this would might* require a small cutout in the door or something like that, for the cable. Alternatively, a pallet carrying a tool battery charger that has a USB port could have a small shelf attached directly to it.

*Why not?

**Wiktionary has it.

N/A [2019-09-18]