Using 20v Lithium drill/tool batteries for RC.

[beavercreek]

I have come into the possession ofsome spare new WORX 20v 2ah and 4ah lithium 'powershare' batteries.
As they are not so big and heavy as the older NiCads I immediately thought about using them for making some RC installations in a few diesels.
The diesels are going to be USA Trains larger models, LGB Genesis and a couple of following wagon installs for attaching to rod steam engines.
They will all have sound (Phoenix) and will use the Crest Revolution RC control except one which will use DCC with RC
I have a couple of the WORX chargers and also a couple of power connectors that fix into the power contacts of the batteries (bought from a guy who makes them and sells on Ebay
My question is..
Fusing (in case of probs and anything else )
Fuse both power cables or just the positive?.
What level of fuse would be a good idea?

Is anyone else using drill/tool batteries (lithium) for their locos and are there any caveats?

 

[PhilP]

Fuse to suit the requirements of the loco. - Two Amps will probably be adequate.

Only charge with the correct chargers.

If the packs contain protection, or BMS boards, leave them in circuit.

All batteries have the potential (no pun) to pose a danger.
The low internal resistance of Lithium batteries, and the nature of the materials within them, can cause a slightly increased risk if things do go wrong.

PhilP

 

[beavercreek]

Fuse to suit the requirements of the loco. - Two Amps will probably be adequate.

Only charge with the correct chargers.

If the packs contain protection, or BMS boards, leave them in circuit.

All batteries have the potential (no pun) to pose a danger.
The low internal resistance of Lithium batteries, and the nature of the materials within them, can cause a slightly increased risk if things do go wrong.

PhilP

Cheers Phil,
I will use the charger that came with the WORX lithium batteries.
The USA Trains locos will probably need more than a 2 amp fuse as they do draw a fair old current when working hard (on my gradients they have to!) so I will use a 5 amp one or maybe even 6.

 

[PhilP]

Cheers Phil,
I will use the charger that came with the WORX lithium batteries.
The USA Trains locos will probably need more than a 2 amp fuse as they do draw a fair old current when working hard (on my gradients they have to!) so I will use a 5 amp one or maybe even 6.

Start at 3A, and work your way up, if necessary..

Most fuses have a rupture current of near double the value printed on them.

PhilP

 

[dunnyrail]

Do you intend mounting the batteries in the loco and removing for charging? If so this will be a real pain. If not great care will be needed on whatever means and wiring you will carry out to connect the trapped batteries for charging. Look for safety advice on what can occur if you get anything wrong.

 

[Fred2179G]

In my experience (20+ years of battery r/c with 5 yrs of Lithium Ion,) the Li battery protection modules work as advertised, and the 'problems' always seem a little over-wrought. A fuse should not be needed.
That being said, until you have more experience, do follow the above advice! Do confirm that the batteries have a protection module (BMS as Phil calls it.)

Charging through a small 5.5mm×2.1mm plug [standard power plugs for LED strings etc.,] is usually easy to set up, but make sure the charger only uses 2 pins/pads to feed the battery from the wall plug. If it has more, it may be a balance charger and you will have to charge the batteries in the original charger.

 

[JimmyB]

In my experience (20+ years of battery r/c with 5 yrs of Lithium Ion,) the Li battery protection modules work as advertised, and the 'problems' always seem a little over-wrought. A fuse should not be needed.
That being said, until you have more experience, do follow the above advice! Do confirm that the batteries have a protection module (BMS as Phil calls it.)

Charging through a small 5.5mm×2.1mm plug [standard power plugs for LED strings etc.,] is usually easy to set up, but make sure the charger only uses 2 pins/pads to feed the battery from the wall plug. If it has more, it may be a balance charger and you will have to charge the batteries in the original charger.

Most tools I have seen have connections for each cell plus a negative, so the specific charger ensures the battery is balanced during charging.

 

[dunnyrail]

Most tools I have seen have connections for each cell plus a negative, so the specific charger ensures the battery is balanced during charging.

Ah that explains the more than 2 connections on my drills, have wondered about this for ages. Not sure what this means for self made setups though.

 

[Fred2179G]

wondered about this for ages.

I have not taken the time to investigate the difference between balanced charging and just giving the whole pack a single voltage charge. I don't think it makes any difference in our application, where the batteries seldom run down to the cutoff voltage and we (me anyway) don't leave our batteries in the charger when not in use.

(One big advantage of LiIon batteries is that you can leave a loco on the shelf for a year and the battery will still be charged when you take it down again.)

I would suggest using the original charger, which will mean setting up your loco so you can remove the battery and replace it. At least you get to put in a new one and continue running.

 

[Degauss]

Most tools I have seen have connections for each cell plus a negative, so the specific charger ensures the battery is balanced during charging.

My drill battery has 3 terminals being + - T. The centre one T is connected to a thermistor.

 

[beavercreek]

Thank you boys for the info.
What I was intending is having the WORX battery permanently inside the diesel hood (or steam loco tender) with a connector slid onto the battery connector pins that would connect to another connector on the underside of the 'tank'. This would allow a double ended connector to connect the WORX charger.
This would entail the making of the special connectors

 

[beavercreek]

Hi again boys.
Well I have had a complete u-turn ( much like the many of our esteemed government I believe) and have elected to drop the WORX 20v 2AH lithium tool-battery route and continue to go with commercially available Lithium packs from providers like RS. These have just two wires for power out and charging and have onboard protection boards etc and while the brand new Worx batteries were ‘extra’ to the amount that I need for my tools, I can sell them to partially offset the cost of the RS packs.
The RS packs are only 14.8v 2.5ah but have proven to be okay for some of my locos that have lower draw( like LGB F7s, LGB Moguls, USAT NW2 and S4 and Bachmann Annie’s). I have an issue with following tenders and ‘battery cars’ due to my very heavy gradients taking their toll

The only problem is that my heavy gradients take a fair bit of the juice to overcome so running time is not huge.
For the big jobs like USAT SD70, Geeps etc I will get A 18.7v pack with higher AH.

The extra connectors etc necessary for utilising the Worx batteries to live inside the locos and be able to use the WORX charger would have needed a bit of faffing about so let’s go the simple way!

I do thank you all for your inputs!