Old Crow
Searching....
I installed a CTEK CTX Battery Sense gizmo in my Hawk's battery compartment yesterday to see what I can learn from it.
It's a $50 device you attach directly to a battery's terminals to monitor its state of charge (SoC). The device (the 'sender') collects data for retrieval via your phone (or tablet) running a free companion app (CTEK Battery Sense).
I know many Wander The West members run Bogart or Victron-brand monitors and I may eventually get to that. But at this point my needs are relatively simple (no solar, no fridge, single battery) so I wanted to try this.
I ran into a few small problems, the most significant being the size of the terminals on the wire-ends of the device. They're only 1/4" (M6 metric) so I made up a short length of wire with larger terminals. I got lucky here in that I had wire and terminal lugs leftover from my recent DC-DC charger install. I chose to make an extension rather than cut off and replace the old terminal in case I needed to return the device.
The other minor problem was finding the app on the App store. A search didn't find CTEK at all. And since I was using an iPad (Mini4), I had to change the filter to 'iPhone-only' for the search. (The iOS version of the Battery Sense app is an iPhone app). And even then a search for Battery Sense returned many other battery-related apps. I finally found it after scrolling down 22 lines of other apps. It downloaded and started up with no other issues.
When the app starts the first time, it asks for an 11-character identifier string from the sender unit. I had already zip-tied the sender in place so cut it loose to read the string. (Tip: the ID string is also printed on the outside of the box it came in.)
So on to the display:
Once the sender connected with my iPad, the app did something interesting. It put up a screen showing 80 amp-hours. I don't know if that's a default value or something it calculated. I entered the published amp-hour rating -- 105ah (and will discuss that further below).
On that same screen the app had an optional opportunity to add a photo. I ignored it at that point but later came back and took the photo you see using the app (after it asked for permission to use the camera).
So we see from the detail screen that the app is telling me my battery is 83 percent full. Yet it shows a voltage of 12.62, a voltage I typically think of as close to full. I know, for example, that the resting voltage will be something like that after any of my various battery chargers declare it full.
Offhand, I'm inclined to believe the 83% number. My battery is over seven years old and its days of being a 105 amp-hour battery are long gone.
The other interesting thing is it shows me a graph of the battery's state of charge over time. I'll be interested to see how that graph changes as I use and recharge the battery.
Other notes:
Voltage and temperature are not shown by default. I had to turn them on in the Tools screen. I also had to change Centigrade to Fahrenheit....
The sender communicates with my iPad over Bluetooth. I have the sender zip-tied above the battery and this morning I was happy to see I could get the battery's voltage reading from the driver's seat of the truck. What I DIDN'T expect was to be able to get a reading from inside my house (with the rig in the driveway). It must be approaching the limits of Bluetooth as it won't update with my home's window closed but will if I open the window.
I also like seeing the temperature in the battery compartment.
-Old Crow
It's a $50 device you attach directly to a battery's terminals to monitor its state of charge (SoC). The device (the 'sender') collects data for retrieval via your phone (or tablet) running a free companion app (CTEK Battery Sense).
I know many Wander The West members run Bogart or Victron-brand monitors and I may eventually get to that. But at this point my needs are relatively simple (no solar, no fridge, single battery) so I wanted to try this.
I ran into a few small problems, the most significant being the size of the terminals on the wire-ends of the device. They're only 1/4" (M6 metric) so I made up a short length of wire with larger terminals. I got lucky here in that I had wire and terminal lugs leftover from my recent DC-DC charger install. I chose to make an extension rather than cut off and replace the old terminal in case I needed to return the device.
The other minor problem was finding the app on the App store. A search didn't find CTEK at all. And since I was using an iPad (Mini4), I had to change the filter to 'iPhone-only' for the search. (The iOS version of the Battery Sense app is an iPhone app). And even then a search for Battery Sense returned many other battery-related apps. I finally found it after scrolling down 22 lines of other apps. It downloaded and started up with no other issues.
When the app starts the first time, it asks for an 11-character identifier string from the sender unit. I had already zip-tied the sender in place so cut it loose to read the string. (Tip: the ID string is also printed on the outside of the box it came in.)
So on to the display:
Once the sender connected with my iPad, the app did something interesting. It put up a screen showing 80 amp-hours. I don't know if that's a default value or something it calculated. I entered the published amp-hour rating -- 105ah (and will discuss that further below).
On that same screen the app had an optional opportunity to add a photo. I ignored it at that point but later came back and took the photo you see using the app (after it asked for permission to use the camera).
So we see from the detail screen that the app is telling me my battery is 83 percent full. Yet it shows a voltage of 12.62, a voltage I typically think of as close to full. I know, for example, that the resting voltage will be something like that after any of my various battery chargers declare it full.
Offhand, I'm inclined to believe the 83% number. My battery is over seven years old and its days of being a 105 amp-hour battery are long gone.
The other interesting thing is it shows me a graph of the battery's state of charge over time. I'll be interested to see how that graph changes as I use and recharge the battery.
Other notes:
Voltage and temperature are not shown by default. I had to turn them on in the Tools screen. I also had to change Centigrade to Fahrenheit....
The sender communicates with my iPad over Bluetooth. I have the sender zip-tied above the battery and this morning I was happy to see I could get the battery's voltage reading from the driver's seat of the truck. What I DIDN'T expect was to be able to get a reading from inside my house (with the rig in the driveway). It must be approaching the limits of Bluetooth as it won't update with my home's window closed but will if I open the window.
I also like seeing the temperature in the battery compartment.
-Old Crow