November 17, 2013

Cap Boosters: What charges to load?

Eve is full of under-explained topics.  As a pilot who likes to fly Gallente ships for PVP with the heaviest blasters possible I often end up fitting cap boosters.  I also then get stymied by what cap charges to put into the booster.  There is rarely a integer number of charges that fit into a particular booster, so which to use. So lets look at that and the two goals of your cap booster: maximum sustained capacity and maximum instantaneous boost.

Medium Capacitor Boosters and their Charges
Here are the medium capacitor boosters you might consider and the standard (not Navy) charges you might consider.

Cap Charge100150200400
Cap BoosterCapacity
Medium Meta 432800 (8)
8.33/s for 96s
750 (5)
12.5/s for 60s
800 (4)
16.67/s for 48s
800 (2)
33.33/s for 24s
Medium Tech 2401000 (10)
8.33/s for 120s
900 (6)
12.5/s for 72s
1000 (5)
16.67/s for 60s
800 (2)
33.33/s for 24s

So if you fit the Meta 4 Electrochemical Capacitor Booster I you have a capacity of 32 m3 and the Cap 100s are 4 m3 each, neatly fitting 8 of them.  Which means you'll get 8.33 GJ/sec until you hit the reload.  Both of these have a 12 seconds cycle time, so that will happen after 96 seconds.

Lots of numbers, I know.  So what does all that mean.  Let's think back to why you fit these things anyway.  In general you have a tradeoff between consistent sustained capacity and maximizing the instantaneous boost you get.

Max Sustained Capacity
In this case you want to keep your capacitor running for those hungry modules like the Heavy Neutron Blaster IIs on a ganked-out Thorax.  You only need the capacitor running long enough for the either opponent to be melted or you've been gunned down.

EFT or Pyfa will give you how long you'll be able to run your ship and that's fine.  Depending on how much you've overloaded your ship you may need to run into the bigger sizes and will have a shorter run time or you can go for the smaller ones and even hit cap stable if you really want.

Max Instantaneous Boost
I didn't really think about this part as much until I was chatting with a friend after an encounter with a neuting opponent.  Maybe you've also watched some of the great Eve videos out there by the likes of kil2 (now CCP Rise).  Under neut/nos attack (or "cap pressure") the constant flow of smaller charges may be sucked away as soon as they land. Notice that the Medium Unstable Power Fluctuator I also has a cycle time of 12 seconds and will pull 180 GJ out of your ship.  If you're using Cap 100s or 150s you won't be able to make any headway.  A charge of a Cap 400, however, may give you enough to pulse that AB and your guns one more time.  Yes, you'll hit reload sooner, but at least you can do something.

So in the past I've only loaded one set of cap charges into my ships.  After going through all this I'm tempted to store up a few of the bigger ones to swap to if I'm getting into combat with a ship that is likely to have neut/nos capability.

Cost - and Navy Charges
More expensive, but what do you get for that?

Medium Meta 41000 (10)
8.33/s for 120s
1050 (7)
12.5/sec for 84s
1000 (5)
16.67/s for 60s
800 (2)
33.33/s for 24s
Medium Tech 21300 (13)
8.33/s for 156s
1200 (8)
12.5/sec for 96sec
1200 (6)
16.67/s for 72s
1200 (3)
33.33/s for 36s

Right now in Jita: Cap 400 - 3,300 ISK, Navy Cap 400 - 115,000 ISK

I used to shy away from the navy charges.  But considering that I'm about to risk a ship around 50M ISK, I figure the 1M I might spend on the navy cap charges are worth it for the substantial increase in the length of time I'll have before the booster goes into cycle.

I'm sure there are some advanced topics but they build off of this that I'm not familiar with - for instance I understand faction/pirate boosters handle heat better even if they have the Meta sized capacity, so you can run them harder.  If you have some other uses for boosters, please do post a comment and share.


  1. From what I recall, the rule of thumb is to load the biggest cap booster charges which will fit into the cap booster, unless the boost will grossly exceed the ship's maximum capacitor capacity. The idea is that it is better to get a big boost of energy now, rather than two small boosts which might not let you power everything at once.

    Navy booster charges are almost always worth the price premium.

  2. Navy 400 can fit in a T2 small cap booster. It slow, but the reload time isn't too bad. If you only need short bursts, its a good option for cruisers.

  3. You're missing navy 800s on your second chart. For the larger charges (400s and 800s), reload time is going to be much more of a significant factor. So to calculate a sustained GJ/s value, factoring in reload time, you get these figures:

    meta 4 booster w/ navy 400s = 23.5 GJ/s
    T2 booster w/ navy 400s = 26 GJ/s
    either booster with a single navy 800 = 36.4 GJ/s

    If you have anything cap-intensive (such as an armor rep, guns, etc), if you're not using navy 800s, you're likely doing it wrong. The only time where it might make more sense to use smaller charges is if you've got something that just needs a bit more cap stability, like a kiting caracal. Navy 200s would give you a bit more flexibility in that situation.

    1. Thanks - that sounds like it fits with the other feedback I've been getting on and off the blog. And yeah, I didn't put the largest and smallest caps on the table since it'd blow out the horizontal direction on the blog - and the blog was more about exploring the relationships between the factors.