I actually would be in favor of lightly increasing the cost of the t2 turret and then applying ammo across the board with the turrets. Make t1 turrets cost like it does now, and able to kill 3 tanks or 6 bots before stopping for reload. Make t2 turrets cost a bit more, have a threshold of 14 tanks or 14 bots (higher damage shots) before reload. Make t3 turrets have unlimited ammo with t2 damage, possibly a cost increase, and even though it becomes the impenetrable one, it can be hit long-range by then. Man that would be nice, I liked the new idea with the turret range but couldn't help but feel that would encourage t1 beats tzero, t2 beats t1, and t2 range beats t2. I liked the range idea because one could always add a new turret to an old turret and combine their firepower while updating their usefulness. I like the tower idea because it literally gives it a threshold for how big an army it could kill, and having an army in reserve even gives you reaction time to move the army in while the turret holds them off just long enough. Walls still need a mild price increase with this too lol. Even with grenadiers, walls should not stop everything else, and the health is fine it is just the repair speed due to their low cost of health per metal, you barely spit nanolathe at it and refill thousands of it's health, if it costed more than it's health would cost more and it's repair speed would be hopefully smaller than the damage speed of 2 tanks? Ammo regeneration increase on combat fabber's target, well that would be useful but only balanced if the rate was literally 5-10%. That still means 10 combat fabbers increase ammo by x2, but you have to be careful of that. You need to make sure the combat fabber costs more than just sticking up another unit.
I think some of the experimental balance changes are attempting to fix this problem, like the grenadiers, and increase range of tanks.
If you use the ammo system as currently in PA, the turrets would basically have 2 different DPS values. When the turrets are fully loaded they would have a higher DPS value. Once the ammo is depleted they would have a lower DPS that is dependant on the rate of recharging ammo. You can basically set those 2 DPS values entirely independent from each other by adjusting the recharge rate of ammo.
I like the idea of batteries. I also like the idea of having to build energy supplies next to them in order to keep em juiced. Disable the energy and the turret will eventually run out of juice.
Don't do adjacency bonuses... Adjacency bonuses are bad, m'kay? Just have turrets chew through energy. They don't need an "ammo" system per-say, they need to interact with your total storage a bit more.
I'd like to see the TA style energy usage (immediate deduction from current storage, can only fire if enough is stored) used in addition to current charge-up style ammo system for different units in PA. They function differently, and using both allows more diversity than just one.
I like the idea of ammo system, or use of energy for turrets. I just hope we don't end up with too many arbitrary designations of what will have ammo or use energy, which will just cause confusion for some players.
I don't like the TA style system. You either have enough energy to supply your defenses or not and if you don't have enough energy you can turn off other energy draining sources to power your defenses for the few seconds that you need to supply your defenses with the extra energy during major enemy assaults. The energy demands from defenses have to be huge if this is supposed to actually have an effect on strategy.
I liked it for the big bertha and stuff, it really gave a feeling like it was the top-of-the-line weapon shooting, like, nuclear bolts of energy. For PA, i think the problem is that you'll notice a huge drain on your energy but you have no clue where it's coming from. I think it's better to leave the ammo system as-is, allowing you to defend and having the cost be in the recovery (of ammo) and not in the defense itself. After all, that's the point of storing ammo.