Scan Tools That Have No Batteries but You Wish They Did
Five years ago I was hired by a tool company to be an idea guy. My job was to go to shops and locate tools that could be manufactured and sold to the automotive world. I helped a few technicians bring in extra cash for their ideas. Along with the ones I submitted for other technicians, being a tech myself I submitted my own ideas. I even was able to get my name on one patented tool called the Bluetooth Trailer Tester. It allows you to test vehicle side trailer wiring through an app on your phone. In July that ship sailed along with the fun I had gathering ideas and taking them to market.
Since leaving I have submitted ideas to the company I worked for with no resulting agreement or contract. I decided to build one of the ideas myself. If any of you use the older Blue Autologic or the new Autoland Scientech iScan III tools, you know how frustrating it is to wait for bootup. It seems you can go make a sandwich and come back and it is still booting. As time is money, I wanted a way to keep the tool booted so that it could be moved from one vehicle to another without waiting for the startup.
Another frustrating issue is when you have a sick car and every time to turn the ignition to start it starves the OBDII power causing a reset. You can add the Tech 2 and any other pass-through to that list. What I wanted to create is a product that would stabilize the output during a glitch. And what about kicking the cable? Just at that critical time the vehicle acts up, you hop in kick the cable and loose vital data. I just finished my first prototype. It is ugly and not suited for the field yet. I thought I would share. I am open to offers if someone wants to build this commercially.
The first problem to consider is the power storage. There are tons of Lithium Ion cells out there. I wanted to use the flat Lithium Polymer cells like found in many current scan tools. The trick is, the voltage does not match vehicle system voltage. Go with 4 - 3.7v cells and you have 14.8 Volts which makes charging more difficult. Go with 3 - 3.7v cells and you only have 11.1 Volts. (Advertised) Since most scan tools can function at lower voltage, I opted for the 3 cell 11.1 volt design. The batteries were going to have to function in series. This requires circuitry that will balance the charging rate to each cell. This helps to prevent a "thermal event". I found a balancing board that would also regulate the voltage.
The batteries I chose were 3.7v 4000mAh Lithium Polymer batteries. I bought 3 of them on Amazon.
I soldered the battery leads to the board in series.
I stacked the batteries and used some Scotch Sticky one sided insulating tape between each layer then taped them together.
I took the input / output leads and connected them to a male and female DB15 connector and jumping all the leads. I then cut the power and ground leads.
I soldered the ground output from the balancing board to the ground lead of the DB15. (test subject is Autoland Iscan II using DB15 connector)
The Power lead was also soldered in but with a diode so that vehicle will not draw from the battery but the scan tool and battery pack can draw from the vehicle.
Theoretically, based on the average current draw (just over 1 amp) of the Autoland, the battery pack should last between 2.5 and 3 hours.
One problem with the current design is that the balancing board requires a kick of voltage from the outside to start supplying power. This works fine when connecting to the vehicle. It does prevent the operator from starting the tool and then walking to the vehicle while booting up. I suppose the tool could be booted when connected to the charging station. I would like it to be possible to start it on it's own. I would also like to add a power switch and charging LEDs. This would let you know the state of charge at any time instead of guessing if it needs to be charged.
Thinking about this device, It would be useful when working with testing tools with undersized batteries. I am thinking of my Bosch Labscope. That battery only lasted 10 minutes when new. Adding a power pack like this or maybe even greater storage may be a good option. That would prevent picking up nefarious signals from the AC power source or from the vehicle. Some of my customers use lead acid batteries on a cart for this. Having a compact source would be beneficial. Especially if it lasted two to three hours. Having a somewhat off the shelf source for replacement batteries is nice too. Much better than getting hammered by the tool manufacturer.
Testing the Battery Pack....
The tool has been on for two and one half hours and still running. Looking at the 10.66v I expect I am getting close to usable time. It is plenty of time for the applications that I intend it for. If the iScan III has the same pinout, I will try it and see how long it can go. The end product will use OBDII connectors so that it is universal. I expect to test that in a couple of weeks when the cable ends and project cases arrive.
No sooner had I bought my own Tech2 than I read how I can damage it with a low-battery vehicle. Since nearly every car I see at the shop has a weak battery (short trip use and/or rare use) my Tech2 lives at home. This is a fantastic idea Mike.
Sounds like an awesome idea. Can't understand why tool manufacturers don't get how important a battery can be in a scan tool.
Awesome! I am WAY on board with your endeavor. Now, have it make the sandwich as well....
A link to the trailer tool if anyone wants one. I used it, love it. pro.steelmantools.com/bluetooth-trai…
Excellent idea! If you call me at the shop, I will give you my email address and send you a couple of suggestions (I do not find an private contact option here). I have thought of numerous tools over the years, but I have always seen that production on my own is nearly impossible to accomplish, and working with a tool company is almost certain to result in heartache. The company which you
Hi Michael: This is a great idea! Kudos for all of the brain power and effort! I have one comment for you to think about for enhancing the project. This project would likely be more flexible and easier to manage by using an embedded microcontroller and a few lines of software code. This would permit more I/O and a display, and the battery balancing circuit board could be eliminated by using a
Thanks Mark, You speak as a true engineer. I have to blacksmith my way through things. My electronic design skills are pretty limited. I will look into the class.
Mike, Is there a way through software or hardware configuration that you could have it tap into 4 cells at bootup and then revert to 3 cells once up and running? Bob
Hi Bob, I am sure that could be done. It is beyond my abilities to design such a circuit. The kick I mentioned is a requirement that power is applied to the output before it will function on it's own. It is a quirk of the balance board. Even with a four cell version the problem would be the same.
Hi Bob: Yep.....it can easily be done with a little hardware and software. I suspect it could be optimized after an initial build to really shrink the product and add more features without much effort. It's just hardware and software......anything is possible. Mark
Hi, I think that is a great idea and would be very useful especially for a mobile technician. I would like to make a suggestion. Do you think it would be better to work on just a cable that is designed to connect to a small compact Lithium booster pack (the small ones that fit in you pocket, most techs have one). with a spike protection circuit that also supplies a steady consistent voltage
Hi Nick, That is a good idea. I still want to maintain the boot on some of these tools which would take more current draw and storage than most small battery packs. The current prototype is not much larger than an external hard drive. With the project box it will be a little larger. Still not any bigger than a breakout box. It could even be integrated into a breakout box. See attached picture.
Hi, The small size is really important, nobody wants to be lugging around a heavy battery with their scan tool. Great Idea. Nick