Hey all. I’m following this tutorial as I build my table. My wife is concerned about the power cable extending across the living room (even between the couch and the table), and I agree that it’d be nice to cut the cord.
Apparently I can’t include links in my post. I’ll try to attach them as comments?
I have a few black and decker tools that run on Lithium batteries (link above). These batteries are all 20v, and some have a “1.5AH” and others have “2.0AH” on the side. There is also a “MAX” above the (v) in 20v… i’m not sure if that’s a marketing term (To the max!!) or an engineering term (these will run at 20v max, but will also run at lower v).
Questions:
Is this possible to run the table from these batteries?
What is the expected runtime off one battery
2b. I am assuming the 1.5AH and 2.0AH specify the capacity of the battery, in “amp hours”.
Can I integrate this without modifying the instructions from the creator? (essentially replacing the power brick)
What components might I need to get this working?
Regarding Q4: I have multiple charging stations (see link to battery above) that I could use as the dock for the batteries. Are there electronics in that I need to change/remove? Can I use the cable from those and wire that directly to the power input from the instructions.
Thanks! I can give more details as we get into this!
Some of those batteries need some logic to get them to spit out the 20V. You should try to get them to power something and see what voltage it spits out. If it spits out 12V by default, then you will want to know that.
The controller and motor drivers will dictate what voltages you can use. They usually say something like 9-24VDC.
The Amp Hours is exactly what you think. If it is 2.0AH, then it will provide 2A for one hour, or 1A for 2 hours or 0.5A for 4hrs. You will get to set the current usage on each driver. You can set it pretty low, because there isn’t much risk and it doesn’t have much force. 250mA per motor is reasonable if your machine is working well.
Summary: the voltage will be determined by the battery. The amount of current it uses will be determined by the settings on the motor drivers. Expecting 0.5A seems reasonable to me. You can easily lower it or use more to have a less fussy machine.
Something else to consider: lithium Ion batteries can be dangerous when they are over discharged. In some manufacturers the discharge protection is in the tool not the battery pack.
Some of the usual suspects sell battery ‘lids’ for using power tool batteries in the way you want. You could check if there are some available for your flavour that includes protection.
It’s a neat idea. So long as you can work out the draw and you’ll get a decent runtime I see the appeal.
This looks promising, David. If we are assuming 2 motors, arduino uno with CNC shield, arduino nano, Raspberry Pi, and LED Strip, would that make any difference? The project calls for a power supply of 2A or greater, but I don’t know how many amps the completed electronics will pull…
If the battery supply is sufficient, Can we expect somewhere in the neighborhood of 10 hours of battery, plus the ability to run off wall power when needed?
I used a porter cable battery for a while. The table and all that works great for 6-8 hours I think. I have a 3’x5’ table so as soon as I added the led’s I got about an hour.
I added a voltage regulator and a battery level monitor to cut it off…I killed a battery letting it go too far.
For the price, it would be better to get something like David linked.
Totally depends on actually amp draw. LEDs and raspberry pi will burn more power. If the project really needs 2a, then a 6 amp hour battery would only last 3 hours.
If you choose a power bank that outputs 12v and 5v it also removes the need for an additional voltage regulator. I have a 20aH Anker battery that does that.
I know this is getting away from the original ‘use the batteries I already have’ concept but killing one of your 20v batteries would be a shame. Not to mention pricey to replace.