When a portal is burned out in ingress, how long until it's hackable again?
According to this site, the significant time is about 4 hours.
I've found that it is 4 hours from the time of your first hack. And it is triggered after you have successfully hacked the same portal four times in four hours (e.g. the fifth hack attempt will result in the "Portal burned out!" message.
What I haven't determined is if this is a rolling four hour window.
For example, you hack Portal A at 08:00, then again later at 11:00, 11:05 and 11:10. If you attempt to hack Portal A again at 11:15, you'll get the "Portal burned out!" message. But, if you try again at 12:01, your hack will be successful (because four hours have elapsed since your first hack at 08:00.)
Now, if you attempt a sixth hack at 12:06, will it succeed because your "clock" has been reset at 12:00 and you now get a full four hacks in the next four hours? Or will it fail, because you have hacked the portal successfully four times since 11:00?
Further testing is needed.
The burn-out timer starts with your first hack as mattozan said and is
4 hours.
Hacking without mods
Hacking at 08:00, 11:00, 11:05, 11:10 will lock the portal until 12:00.
Hacking the portal at 12:01 will be successful.Hacking at 08:00 and then waiting until 12:00 will also result in refreshed timer and hack amount, meaning that 4 hacks will be available again, not only 3.
Multi-hacks
If a portal has, say, Common Multi-Hack (+4 hacks) and you hack it 3x at 08:00, 3x at 09:00 and someone destroys the multihack, portal goes automatically into burn-out state.
Likewise if a portal is burned-out and you place a Multi-Hack on it, you will be able to hack it immediately - the burn-out state gets postponed.
Heatsink
- The user who places a heatsink on a portal can immediately hack again, moreover, the hackability is completely refreshed for him and his 4h burn-out timer restarts.
- See more info on heatsink mod here
Protip: Farms
- Knowing all this can be 'exploited', especially when a farm* is planned.
Say a farm with RMH, 2x RS + turrets/force amps is planned at 12:00. All players will visit the place and hack all the portals once at 09:00. This will activate the burn-out timer, which refreshes portal's hackability at 13:00. At 12:00 players assemble again, build up the farm and start hacking. Rare Multi-Hack gives +8 hacks = total 12 Hacks. 1 hack was already made 3 hours ago, so it is 11 hacks left. After 55 minutes the 11 hacks are done and portal goes into burn-out state, however it's by the time the burn-out timer kicks in and refreshes the hackability of mentioned portals, giving players another 12 hacks.
= Total of 23 hacks with only 1 Rare Multi-Hack
*What is a farm
A Farm is a local community's 'event' at place with high density of portals. It's basically when a group of players levels up portals for the sole reason of obtaining items from them. They keep on hacking them until they burn them out, or until their inventories are full. The farm is usually of a certain level and when mentioned in chat, players use the term F8 there and there. If there are some multi-hacks or heat-sinks used, the notification could be as follows F8 2xVRMH VRHS, or when 1 last player is needed F8 1xR8 missing.
CMH, RMH, VRMH = Common / Rare / Very Rare Multi-Hack
RS = Rare Shield
VRHS = Very Rare Heat Sink
F8 = Farm of level 8 portals
R8 = Resonater level 8
A8 = Agent level 8
What are the meanings of most common abbreviations in Ingress?