EV CHARGING COST LOG
VoltLog
EV Charging Cost Log
Most charging logs multiply kWh by one flat rate and stop there. If you charge overnight on a cheap window that number is wrong, sometimes by a factor of three. VoltLog prices each charge by the time it started and divides by the miles your odometer actually recorded.
14-day trial, no card.
From $1.99 a month.
Here is the whole argument, worked out. One car, one top-up of 30 kWh, doing 3.9 miles per kWh. The only thing that changes is the hour you plugged it in.
Plugged in at 19:00 — standard rate
6.3pper mile
Plugged in at 01:00 — cheap window
2.2pper mile
01
The gap between two consecutive charges that both carry an odometer reading is one leg. Distance, energy and cost are all taken from that same set of legs, so they cannot drift apart. A charge you logged without a reading still counts its energy and its spend, it just adds no miles. A reading that goes backwards, or jumps implausibly, is dropped rather than allowed to wreck every derived figure.
02
Charge in Calais and Dover in the same month and VoltLog shows you two subtotals, not one meaningless sum. Cost per mile is worked out inside a single currency, using only the legs paid for in that currency, because dividing one currency's spend by everybody's miles quietly understates the answer.
Every charge carries where it happened, and the dashboard shows the split by energy, not by number of sessions. A 3 kWh top-up at a supermarket and a 60 kWh motorway stop are not the same event, and counting them as one each hides where the money went.
Public charges take a network name, so the app can rank the average price per kWh you have actually paid at each one, cheapest first. Saved places, "Home", "Office", the Tesco you always use, prefill the network, the location type and the usual rate, which is what turns logging a charge into a few taps. They are labels you typed: no coordinates, no GPS, no location permission.
Vehicles, rates and totals in these screens are the app's built-in sample data.
SAID PLAINLY
Nominate the car's stereo as your car, and when it disconnects from the phone, which is the moment you parked, VoltLog can raise a notification that opens a charge entry with the date, the place and your odometer already filled in. You still type the kWh and the cost.
It works that way because a phone cannot see a charging cable, cannot read kWh, and cannot know what a charge point billed you. Anything on a phone claiming otherwise is reading the car's telematics account, which VoltLog does not do. The reminder exists because forgotten entries are what kill a manual logbook, and you can set how often it is allowed to prompt.
PRICING
$9.99a year
$1.99 monthly · $19.99 once, and it never renews
Fourteen days of everything on install, no card. After that, logging charges and reading your history stay free with a banner ad, and nothing you have entered is ever locked away.
Logging charges, the dashboard and everything you have already entered are free, with a banner ad. Pro adds off-peak tariff pricing, the charts and the reports: $1.99 a month, $9.99 a year, or $19.99 once. Every install starts with a 14-day trial of all of it.
No. You enter the kWh and what it cost, or let a saved tariff work the cost out from the time you plugged in. Nothing connects to a charge point, a network account or a vehicle API.
When the car you nominated disconnects from your phone, which is the moment you parked, VoltLog can send a notification that opens a part-filled charge entry. It is a prompt so the entry does not get forgotten, not automatic logging.
Yes. A tariff holds a standard rate plus any number of cheap-rate windows stored as wall-clock times, so they survive the clocks changing. The session start time picks the rate, and a session that crosses a boundary is split across both rates when you give it a duration.
Your odometer. The gap between two consecutive charges that both carry a reading is one leg, and distance, energy and cost are all taken from the same legs. A charge with no reading still counts its energy and spend but adds no miles, so the figure does not get diluted.
There is no account and no sign-up. If a subscription lapses, nothing you have logged is hidden or deleted. New charges simply go back to being priced at your standard rate.
Put in your tariff, log the next three charges with the odometer, and the number stops being a guess.