Making use of cordless power tool batteries (e.g. 18v)

[ImpatientMaker]

I have a handful of Ryobi 18v batteries for various cordless power tools, and I saw this item on Tindie, which made me think I could power an inverter with these with the right circuitry. Anyone played around with this? I'm not enough of a sparky to figure it out myself.

 

[SolarRat]

I took apart a few old Ryobi batteries. They use junk. I think they were only 1100mah cells and half of mine were unrecoverable because the factory BMS does not treat them well (allows them to drain way below safe levels). You aren't going to power an inverter without a ton of these.

 

[ImpatientMaker]

Perhaps (and thanks for your reply), but they're good enough to power the tools, and I was thinking at the very least I could connect them to my MPPT SCC and give the system a bit more juice.

 

[Supervstech]

Perhaps (and thanks for your reply), but they're good enough to power the tools, and I was thinking at the very least I could connect them to my MPPT SCC and give the system a bit more juice.

Every cordless manufacturer has a generator pack for sale that takes their batteries.

 

[Supervstech]

The issue with trying to build an inverter to use 18v batteries is the lithium ion voltages... nobody makes an inverter that accepts the voltages he batteries use... except for the tool manufacturers...

6s lithium all the 18v use is really a peak v of 25ish volts...just barely in the window for powering a 24v inverter, but voltage drops below the 21v cutoff tooquickly.

 

[ImpatientMaker]

That's why I figured I'd jam them into the solar charge controller since it takes whatever the panel throws at it

I guess I should mention I already have a 12V system that I built (scc, inverter, 100w panel, etc)

 

[Supervstech]

Ok, you want to tie lithium packs into a series arrangement and dump the stored energy into a charge controller...

someone smarter than I am should comment on this.

 

[SolarRat]

My Ryobi packs are 2ah and 4ah. That's not enough to do much. I used my drill/impact batteries on the Ryobi weedwacker and they failed from the high draw...if you want them to last for your drill, save them for your drill. They don't handle much abuse.

 

[namesgolden]

I picked up a extra ryobi weedeater at a thrift store, gutted it for parts. turned the handle into a power station

12v barrel jack output. usb output, and the trigger puts direct 18v out to the stock leads (for popping e-matches or testing stuff)

I'm going to pick up a cheap 100w inverter and see how it behaves the direct 18v.

check thingiverse for 3d printable ryobi gadgets.

 

[gnubie]

12v inverter - overvoltage lockout and/or blow up
24v inverter - undervoltage lockout

 

[JeepHammer]

I don't discount anything...

I'll go with the guys on 2 & 4 Ah not being a lot of storage, but if it's what you have, then that's what you work with.
Work with what you have.

 

[Supervstech]

I picked up a extra ryobi weedeater at a thrift store, gutted it for parts. turned the handle into a power station

12v barrel jack output. usb output, and the trigger puts direct 18v out to the stock leads (for popping e-matches or testing stuff)

I'm going to pick up a cheap 100w inverter and see how it behaves the direct 18v.

check thingiverse for 3d printable ryobi gadgets.

Keep us informed of your progress and results.

some 18v packs are really 25.2v so, a 24v inverter may be somewhat useful, but finding a 24v inverter small enough to run on 4Ah could be tough.

 

[Craig]

If you plug 18v tool batteries into your SCC just be careful they do not output too many amps and blow your SCC that is the danger in your scenario. But from my experience I think you will be . See if they show a maximum amp output rating and als I would use a amp meter the first time just make sure you are not sending too much power.