I purchased a GPS tracker from Amazon and instead of wiring it to the car battery I would like to simply attach my own power battery pack.
I am a complete noob when it comes to electronics and I attempted using a 9V battery. It worked but the GPS tracker stayed on for about two hours. It consumes at 300 mAh, I've been told.
I then attached 8, 1.5V rechargeable batteries with 2300 mAh. How long should it last? Is it simply (8 * 2300) / 300? 61 hours?
What other batteries would you recommend to get the GPS tracker to last as long as possible. No car battery or acid batteries please!
Best Answer
Do the math. You say the thing you want to power takes 300 mA at 12 V. You are powering it from a 12 V 2.3 Ah battery.
(2.3 Ah)/(300 mA) = 7.7 hours
That's of course the theoretical answer. There are a number of things that conspire to make batteries much less predictable than a simple amp-hour rating. The amp-hour rating the manufacturer quotes is usually under the most favorable conditions, so you'll likely get less. At low temperature you can get a lot less. You're probably fairly likely to get at least 6 hours run time at room temperature with fully charged batteries in good condition.