Power tool batteries ??

[DickyC]

As i got such usefull answers from my last posting i have another question for all the micro electrical engineers out there.

I have in the shed some older power tools, The tools themselves have given up the ghost quicker than the batteries (own brand cheap crap with mainly the plastic breaking or mechanism and have never throw away). An example being a screwfix hedge trimmer with a nice recharger, battery pack etc. If and why not is the battery (perfectly usable and hardly used) from this ideal for converting for loco power ? you could even re use the mounting system in a seperate trailer and have the ability to slide it on and off for recharge as you do with a drill or such like ?

Will this fry the circuits and motors (this has been discussed on RC car forums) ? and if so why ?
picture of a spare battery attached

,

 

[PhilP]

You should be OK with that battery..

18V will be plenty. The 1500mAh will be adequate.

NOTE!

The labelling infers this is a Lithium-Ion battery.
DO fit a suitably rated fuse.
DON'T use anything but the correct charger!

PhilP

 

[Cobalt6700]

You will need some form of low voltage cutout (LVC) / protection to use a lithium battery. This is to prevent the cells going below thier minimum voltage.

You will damage a lithium cell by going below minimum voltage, just have a Google for li-ion safety.

Typically with li cells you don't want to discharge past 3.2V per cell. This is above the limit where damage occurs. Being a 18V pack, this will contain 5 series cells, or 5S. The min voltage you should discharge this too (to keep the battery heathly) is 16V.

As PhilP has said, you will also need to charge with the proper charger.

It may be that the pack has its own in-built protection, however this is usually found in expensive batteries. The cheaper stuff (and some of the expensive) usually has the LVC built in to the tool.

 

[JimmyB]

Both the above posts have brought out the most important things, fuse, and correct charger, I can only reinforce these statements, otherwise have fun

 

[The Shed]

One of the Lads up this way has been working on ways to reuse tool battery packs, including 3D printing adapters to utilise the tool battery packs.
He did mention in passing that he was considering penning an article on the subject, I'll give him a nudge as a gentle reminder.

Power Tool Battery Pack Adapters


Have previous form on Tool Battery Packs.........

Picture below, batteries were salvaged from a GTECH Air Ram Vacuum Cleaner, practicable and feasible, usual provisio ONLY attempt if confident and competent!

 

[dunnyrail]

Shed solution a more viable option if you need to save money for using old tool batteries of whatever sort. My big issue is connection if you do not pull them apart, you effectively need a way of connecting the charger to the battery, a real pain if you need to take the battery out of the locomotive each time you need to charge it. Personally I see this as a penny pinching way to get battery power that could easily end in tears, or a trashed locomotive or possibly even house if some of the fires seen on ebay by escooters are to be believed. Yes the batteries have been used in power tools for ages, but with proper precise connections for charging, something not to be messed with.

 

[Paul M]

As Jon and others have said, be careful! TBH, if the tool was that cheap, I'm surprised the batteries have lasted longer. Usually it's a shed full of good tools made worthless because replacement batteries for them cost more than a new tool

 

[KBR]

As Jon and others have said, be careful! TBH, if the tool was that cheap, I'm surprised the batteries have lasted longer. Usually it's a shed full of good tools made worthless because replacement batteries for them cost more than a new tool

I second that warning: some years back I had just parked my car under a beachfront high rise apartment at the southern end of the City of Gold Coast when I noticed the building manager running for he exit with a smoking cardboard box retrieved from the car boot of a vehicle parked across the driveway from my parking spot. He had removed a lithium battery which had shorted. The burning battery belonged to a model plane flyer.
For years now have I been working with a low power [18v DC 24Wh Li-Ion (1.3Ah)] Ryobi One+ tool battery plugged in to the base of an dismantled first model Ryobi torch to power a clam shell LGB Stainz via an early LGB esc device, fuse protected, and all housed in 2 axle open wagon, so far so good. Minimum skill required to connect together this well manufactured group of products, may be a little expensive at today’s prices.

 

[Paul M]

Minimum skill required

The problem is that minimum skill covers a lot of bases.