LiPo Drone Batteries Reuse: Project 1 - Portable Power for Soldering Iron

Introduction

Whoever has a drone for a long time knows that their batteries don't last several years, mainly if you don't use them often. That is my case. I have a drone since 2013 and 5 of its 6 batteries just can't be used to fly anymore. Even after complete charge the drone alarms low battery as soon as it takes off.

The LiPo batteries are the best for drones because they can hold more power in a light weight compared to other battery types and mainly for its high discharge rates, meaning that they can supply high power in a short time period. The "discharge rate" is one of the features one can evaluate when buying those batts. It's interesting to highlight this feature, because the drone really needs it, but a lot of other stuff don't, so, even when they can't anymore give enough current for a drone to fly, they can still power up a lot of other things.

In this tutorial I will show you one of the most simple ways to reuse them, just making a new connector to use them as the source power for a TS100 micro controlled soldering iron.

The TS100 is a very good soldering iron IMHO. When I first saw a review of this product I thought it was a "must have" product for those who use a soldering iron frequently. After starting to solder plastic, as I've shown in this other instructable, I've bought around 5 new irons to try new types. This is now my preferred one. It is lightweight, small, powerful, micro controlled and programmable. I've never seen before a soldering iron in which we could upgrade the firmware lol. For an IT guy like me this is awesome!

Finally I would like to ask everyone to correct any misspelled or misused words as I'm not a native English person. Just make a comment and I will fix it. Thanks!

Ready made solution

Well, just after publishing this tutorial I've found some sellers at this site selling this cable already made and at a variety of prices. I probably would still have done the cable myself, as I already had the things needed to that. Also it would take months to arrive to my house coming from China. Brazilians will understand me. I've also found some at Amazon.

What you might need

1. A dc male connector 5525 (5.5mm x 2.5mm) to the TS100 side - common on notebook's power sources
2. A XT60 male connector (depends on the battery used)
3. Electric cable to link connectors

Optional

1. A LiPo tester low voltage buzzer
2. Heat shrink tubes
3. Instant glue (I have used just after some use to fix the cheap connector I've bought)

Comments on materials

In my case I had already a XT60 with a cable to 4mm Banana Plugs T0650, so I've used it (last picture).

Before thinking of cutting the XT60 connectors to make a direct link, know that you may need to keep the original connector to recharge the battery. Usually common chargers will require them.

The LiPo tester is totally optional. I wouldn't buy one just for this. The TS100 soldering iron will turn off on voltages lower than 10V by default and you can program this threshold between 9-12V. The risk is to permanently damage the LiPo. This battery type can't be fully discharged, so the LiPo tester is just an extra monitoring protection. After many uses I've already stopped using it.

Heat shrink tubes are wide spread, but if you don't know them, take a chance to test, they are far better than tape IMHO.

So, these are the steps I did:

1. As I've used a cable with other connectors (banana plugs) I had to cut them off
2. Then I've soldered the cables to the 5525 connector. Don't forget to put the heat shrinking tube on the cable before. Attention to the polarities.
3. Put some heat to shrink the tube and that's it!

4. The other edge already had the XT60 connector

5. After some use I've noticed that the connector started to bend on it's screw, so I've put some instant glue there to enforce it.

Other possibilities

1. Working with batteries with a different number of cells

A friend asked here what he could do with 1S batteries (batteries with only 1 cell, which gives 3.7V DC).

1.1. Serializing them

One possibility to use them with the TS100 soldering iron is to put them in series. You would just need more cables and connectors. The positive cable of one should be connected to the negative cable of the next and so on. You would need at least 3 cells to run the TS100.

1.2. Batteries with more than 3 cells

Just remember that the TS100 can work with up to 24V DC, so you can use even 6 cells to run it. If you have more than 24V you can then use a circuit board to convert it to 12-14V like this ready made one.

2. Other uses

One of the most used voltage nowadays is 5V DC, to charge cell phones and many other USB based electronics, as audio boxes, etc. You can use a DC-DC step up boost circuit module to convert a 3.7V batt to 5V. Some of these circuits even come already with the USB port. If the battery have more cells there is also a circuit board to reduce it to 5V, called "step down" converter.

And with the regulated one mentioned at the 1.2 item you can expand the range of different uses.

Important note: I haven't done an instructables on using this ready made circuit boards yet, but I've already used them with these batteries. Be extra careful with consumption with them. Remember that these batteries can't be fully discharged or it will permanently damage them. I have damage one just letting it connected to the LM2596 with dual USB ports. For those uses that buzzer would be useful.

Thank you for reading this instructable!