Battery powered tools can be the mainstay for many RV’ers that like to be prepared for both unexpected needs and maintenance when away from home.
I carry a full complement of 18-volt Ry
obi power tools, including a drill, flashlight, reciprocating saw, handi-vacuum, and a small chain saw. Other tools such a air compressors, radios, saber saws, circular saws, and leaf blowers also operate off of the same 18-volt nickel cadmium battery pack. I find myself frequently using the drill with a socket that fits scissors jacks to quickly raise or lower the jacks. The drill also serves as an electric screwdriver that recently came in handy when the base of our bed broke apart. Both the reciprocating saw and the 10” chain saw are great for cutting gathered firewood from downed trees or limbs. Of course, you are limited to small diameter wood.
Using portable battery operated tools requires several spare batteries as well as a proper charger. If the batteries are old and weak and can no longer hold a full charge, it is time to buy replacements.
I found myself needing to replace six 18-volt nickel-cadmium Ryobi batteries at $40 each; this would amount to $240.00. I personally felt that the price was ridiculous, but having only one retail source, my choices are limited.
BTW – if you run across one of those on-line ads for information on how to resurrect nickel-cadmium batteries, don’t waste your money. The method may allow a battery pack that will not normally recharge to function, but the life and durability of the battery pack will never be as good as new batteries. If you really want to know how this is done, let me know – I’ll tell you the method for free.
I noticed that Harbor Freight Tools had 18-volt nickel-cadmium batteries for their brand of tools on sale for $10.00 each (regular price $19.99). This was a great price, but the battery pack will not fit other brands of portable tools. That was when I started thinking, “ The batteries inside this case are the same size and amp-hour rating as the ones in my tools – why not just move the batteries from one case to another and save $180.00 – THIS WOULD BE A 75% SAVINGS!”
Replacing the batteries in the Ryobi case is not a difficult task. But, you do need to understand how single cell batteries may be connected in series to provide higher voltages. Each Sub-C battery will produce 1.2 volts resting. A recently charged Sub-C cell may reach 1.4 volts. A Sub-C cell is considered fully discharged at 1.0 or below volts. As far as basic tools needed to accomplish the exchange, you will need a soldering iron, solder, needle nose pliers, Phillips screwdriver, small wire cutter, safety glasses, and a hot glue gun. A multimeter that can measure up to 20 volts DC is also extremely helpful for checking battery connections and final voltage.
The procedure I used to replace my battery packs may also be used on any other brand of nickel-cadmium powerd tool that uses the Sub-C size battery. The majority of these tools use a cell rated between 1000 to 1300 mh. My Craftsman 12-volt and 14.4 volt tool battery packs as well as one Black and Decker product use this battery to make-up their power packs. An 18-volt tool uses 15 single cell batteries, a 14.4-volt tool uses 12 single cell batteries, and a 12-volt tool uses 10 single cell batteries. If you want more power and run-time than the original batteries may have provided, you may want to spend the extra money to purchase new 2000 mh batteries like the ones shown here available from Amazon or other vendors. They should fit your original case and work with your original charger. The final cost may be more than a new battery, but you will have up to twice as much run-time and power than the standard cells.
You start by taking the screws out of both the old and new battery packs. This allows you to slip off the plastic case leaving you with the assembled batteries.
Step 2 is to take the new batteries and remove any that do not follow the construction pattern of the original battery pack. Reorient the replacement batteries so they are identical to the old battery pack. The metal straps connecting the batteries can be soldered back onto moved batteries. The hot glue gun comes in handy when repositioning spacers and temperature sensors.
These photos show how I accomplished the exchange.
Note how the original battery pack is assembled. The Ryobi 18-volt pack has a single battery that slips into the handle stub.
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This battery pack has a temperature sensor and a plastic spacer that must be reused.
These new batteries were separated from the donor pack. They will be reattached in the proper location by soldering the tabs to the next battery.
Soldering straps to batteries that have been repositioned.
A hot glue gun works well for reattaching sensors and spacers.
Key parts that MUST be salvaged and reused in the Ryobi battery pack.
Batteries are reinserted into original cases. These batteries are "like new" and should last for at least 2 years. I painted some of the cases red to easily identify rebuilt batteries.
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The old batteries should be given to someone that will accept them for recycling. Any Radio Shack store should do this for you.
Again, this can be done on any nickel-cadmium battery pack using the sub “C” size cells. This method is NOT acceptable for power tools using lithium-ion battery packs.
professor95
DIY – I was waiting for that question 🙂
In a nutshell, it works like this. The battery that will not hold a charge in this example is a 18 volt nickle cadmium. pack. You take TWO 12 volt batteries and put them in series to obtain 24 volts direct current. The negative lead from the 24 volt source is clipped to the negative on the 18 volt battery pack. Then, the positive lead from the 24 volt source is tapped onto the positive terminal of the battery pack ten times at one second intervals – you know, tap, release, tap, release, etc. DO NOT hold the positive lead to the positive on the NiCad pattery pack for more than one second at a time. Check the battery voltage – it should be very close to 18 volts. Put it in the charger until the charger shows the charge is complete. Then, totally discharge the battery – I use a 18 volt flashlight. When discharged, put back in the charger – repeat this 2-3 times to establish a new memory cycle for the battery. It actually works for some battery packs, but if 1 or more cells in the pack are weak it will soon return to a bad battery pack. You can only resurrect the pack a few times before you must either replace or rebuild. That said, I have charged battery packs, let them sit and self discharge for a couple of days then measured voltage on each cell. Those that fall at 1 volt or below are removed and replaced with used batteries that check good from another problem pack. When resurrecting 12 volt NiCad battery packs use a good 18 volt battery pack as the “cleaner” (above). For the 7.5 volt B&D Versa Cells use only a 12 volt battery.
DISCLAIMER – wear safety glasses. I am NOT responsible for any potential injury or accident from trying to resurrect NiCad battery packs. Proceed at your own risk.
DIYJunkie
So, how do you resurrect nickel-cadmium batteries?
Professor95
uhhhh… butterbean, Harbor Freight is a privately held AMERICAN company that has American stores, pays American taxes and hires American employees – even if the “stuff” is from China.
http://en.wikipedia.org/wiki/Harbor_Freight_Tools
Funny thing about the batteries – the ones in the tools I swapped out were from China too. I do like saving money but I avoid cheap stuff. You can find good stuff that is inexpensive but not cheaply made if you look around. Great $$$ saving prices on their solar panel kits, solar lights and Haul-Master RV accessories. It would be nice to have the same stuff made in America at a price us poor ol’ retired folks could afford. 🙂
butterbean carpenter
Howdy Randy,
Thanx, for the article!!! Now, if I was only intelligent to follow the directions and had an 18-volt tool I use it..
You do know that Harbor Freight is a wholly owned part of the Chinese government, don’t you… I’ve bought a lot of their products, some okay, some terrible; BUT CHEAP!!!