Battery Pack for 18V Ryobi Tools




This is a quick and easy way to make a battery pack that will allow you to use a Ryobi 18V tool for four times as long as with one battery. Sometimes a tool will die in the middle of an operation, this can mess up what you're trying to do and is dangerous in some cases. Speaking of dangerous! I get the impression that my little project is dangerous, so watch your back and don't get hurt, I believe in you.

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Step 1: Layout

First of all, find a board that you like. It needs to be wide enough that it is at least an inch taller than your battery when stood up on its side. It needs to be as long as all four batteries lined up like in the picture. This is the space saving method of placing the batteries.

Step 2: Drill Action

Figure out where all the +/- connectors line up with the board and drill holes there. Do this again on another board, but mirrored.

Step 3: Ensemble

Cut these two boards and another to the same length, and then two shorter boards for the ends. Screw it all together, as if it were some sort of bird house.

Step 4: Place the Batteries., Then Screw It!

Put the batteries that sit upright in first, then drive screws into the holes that correspond to them until the screws touch the leads on the battery. You can use the screws to help hold the batteries in place by tightening them a little more after they touch the leads.

Step 5: Testing

It's difficult to see if the screws hit their mark for the upside down batteries, this is a good time to have a tester. Lacking that you could run wires from each of the two screws that run to a battery and touch them together briefly to see if it arcs, don't hurt yourself. 19.80V? What sort of 18V battery are you?

Step 6: Connections

So we're trying to hook the batteries in parallel, right? I'm sure there's a better/safer way to do this but this was the first thing that came to mind. I suppose you could tape over those bare wires, or even get the correct length of screws so that they don't stick out so much.

Step 7: Plug It In

You could just attach to your tool with clip leads or something, I made this plug so it was easier to hook up and unplug. I just sanded a board until it was vaguely the same shape as the hole leading into the tool. I then stapled a strip of copper to each side and drove some screws in there so I could attach wires or clip leads or whatever later on.

Step 8: Fin

Looking good, I added a rope so I could carry it around easily. Works like a charm. Also makes a lovely purse, for all you purse lovers out there.

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    16 Discussions


    9 years ago on Introduction

    That's a kinda caveman, "does it actually work" kinda way. well does this actually work?  It's definitely inspirational.  I love my Ryobi one+ (I have the caulk gun, circular saw, reciprocating saw, and 2 drills...don't ask.), but the black/yellow batteries themselves are horrible.  They did fine when I was just running screws here and there, but then I got involved in building a deck, which involves cutting a lot of lumber.  The tools will do the job, but I suddenly find myself constantly switching batteries.  I picked up two of the low-profile battery upgrades, which are much stronger but run out just as quick under heavy loads.  Does running them in parallel give you the results it seems like it should?  The batteries would suddenly be worth having again if a four-pack got me four times the life!  I run a mobile shop out of a van, and a lot of my money goes into battery tech.
    The "good" batteries cost $90/ea at Home Depot!

    3 replies

    Reply 9 years ago on Introduction

    Works pretty much how youd expect.  I wouldnt sayit gives exactly four times the life, but at least you spend less time in limbo, trying to decide whether or not it is indeed time to swap batteries.


    Reply 8 years ago on Introduction

    I'd say it would give your more than 4 times the life, considering this causes a lower draw on the batteries which usualy gives them a higher A*H


    Reply 4 years ago on Introduction

    The power tool's amp draw is exactly the same. Now its just spread out over four batteries instead of one. Therefor in theory it will last 4 times as long.

    But odds are the batteries are old and they'e not even ryobi batteries to begin with so its not an equal comparison.


    8 years ago on Introduction

    this is a joke right? kinda defeats the cordless thing..................


    9 years ago on Introduction

    Never saw this beast before. It seems like a classic though.

    Mr. Rig It

    11 years ago on Introduction

    I LOVE my Ryobi 18volt one Plus tools. They are the best cordless tools on the market for the Non-Professional tool user. I have the leaf blower and weed eater and they. The leaf blower is kinda of weak compared to corded ones but it works fine for what I need it for. The weed eater works fantastic better than my corded Black and Decker. This ible would work well for the leaf blower, it sucks the battery pretty quick, the weed eater does pretty well, though it may benifit from this as well. I am sure the chainsaw sucks the battery down very quickly also so this may work wel for it as well. Ryobi now makes battery that last twice asd long as the preivous ones. When it comes to angle ginders I still use my craftsman corded, but there are times when I could use a cordless one. I would just hate to have to carry that box around. Perhaps you could make your cord longer so you could se it down to use it. Neat idea.


    11 years ago on Introduction

    im pretty sure those ryobi "one"s are crap. the batteries only cost like $30 get a cheap corded angle grinder for less than the cost on one of those batteries, or run that thing off 2 car batteries with a longer cord for serious power


    Reply 11 years ago on Introduction

    Corded tools are definitely always better for power, but when you're working in off the grid locations you've gotta choose between human powered and DC, and for now DC is my pick. What sort of drill do you have? I think anything under 18V for a cordless tool is just a lot of frustration.


    Reply 11 years ago on Introduction

    Or get a generator or inverter. I have a cheap 18v drill (it was $10 at menards).

    Absolutely! That's what I do usually, but the angle grinder drains batteries incredibly fast, which is dangerous when you're using the abrasive cut-off wheel, because if it's not able to chew through the steel you're cutting it kicks back towards you instead, maybe I should put a picture of my papa's destroyed hand on here to illustrate the concept. This is also better than changing batteries out because the amount of peak performance time is increased significantly.