We're paranoid about not running your car's battery down. When the ignition is off, we consume less than 1 mA. By itself, the Automatic Link would take 3-4 years to drain even a cheap battery.
I think it's better to break this down, because this myth of 'running out of battery' is really exaggerated
Let's say your average battery has 40AH. That means it can provide 1A for 40h (or better, the product time(h) x current(A) = 40 for a charged battery) @ 12v
If your lamps consume 24W (I'm guessing), that's 2A, it means it would go from fully charget to nothing in 20h. But of course, your battery is usually not 100% and you need a certain battery capacity to start the engine.
Even if the consumption of this device is 1W while idle (which is really an exaggerated value), the device uses around 0.084A and the battery would take 480h to go from 100% to 0% (or about 20 days)
My guess is that an unpowered car uses more than that by itself, so this dongle is not an issue, unless you're leaving it unattended, you can unplug it but will probably run out of battery nonetheless.
Car batteries don't die after sitting idle for three weeks, not in a normal car with a working battery.
At 1mA of current draw, this device is definitely not a problem. But the idea that an unpowered car uses enough power to drain the battery in less than a month is clearly ridiculous.
Weather is a factor, especially for those living in harsh winter climates. The first "C" in a battery's CCA rating is "Cold." i.e., how much current the battery can provide for 30 seconds of cranking continuously at 0F when brand new. That current rating drops significantly below zero Fahrenheit - http://www.pacificpowerbatteries.com/aboutbatts/car%20batter...
In a climate where 32F may be the highest temperature seen for months, a car sitting idle for two weeks can definitely be in danger of not starting due to the battery not being able to crank the engine after being cold-soaked at -20F all night.
Grew up in Wisconsin. Definitely an issue. I had an old Ford Aerostar that would only give you one chance to start if it was below -10F and if it started, you didn't dare let it stop for a while. :)
Well, when was the last time you left your car without powering it for a while?
If the battery is showing some age, and/or didn't go to 100%, less than a month is typical (depending on the accessories as well: alarm, stereo - some uses standby power, etc)
A few years ago, when I was traveling for about a month. Had no trouble starting the car afterwards.
An older battery surely won't do as well, but then it'll do even less well with an extra 1W draw hooked up. No matter how you slice it, a load that will drain a car battery in good condition in 20 days is a pretty big load.
The current budget for an unpowered car is on the order of 20mA, and they're specced to leave the factory such that they can be left in that state and started after a month.
If you switch the alarm on, that budget increases to something like 120mA, but you'll kill the car inside a fortnight.
I wouldn't call it a myth people have reported issues with similar port adapters, particularly bluetooth ones. If the issue doesn't apply here then great but in general people should pay attention.
My cheap chinese bluetooth obd2 device caused my battery to drain when I was ill for a week and didn't use my car over the christmas holidays. On the plus side now I know how to jump start it.
Thanks, this is good to know since I have one too. I'll have to start unplugging mine (also cheap and probably Chinese, though I got it on Amazon). But I've left it in for several months without issue, I guess maybe I just drive regularly enough that it's not an issue.
I'm not saying a cheap chinese adaptor won't drain your battery, but from what's shown I hope they thought of an energy saving system
It's possible to build it to not use excess energy.
Personal anecdote: Last year I would not use my car for long stretches (between 2 and 3 weeks), as I was traveling. 2 weeks is doable, 3 weeks I'll be certain to have a dead battery on arrival.
I'm glad you replied to this criticism. I'm very excited about your product, and I'm hoping that you are planning on a third party API so folks can build apps for your customers..... maybe that was written somewhere and I missed it??
We'd love to build an API. It's on a long list of things we want to build. The Automatic Link supports OTA updates (through the phone). So, our users can expect improvements. In fact, we think of ourselves as a software company. We built a hardware device because that was the only way we could achieve the user experience we wanted to deliver.
That's very good to hear, the reason why I didn't make talking to the obd port a regular hobby is because my wifi connector would eat the battery up in a few days.
