I thought I would share my HPA fill set up for you guys. I bought a 88cf 4500psi airtank from Mac1 and it's so much better than a hand pump. When the tank hits 2000 psi I take it to get it filled. I wish that I could use more air that's in the tank to help cut cost of driving to get it filled every other week but all my HPA rigs are setup to run best with a 3000psi fill so at 2000psi it's time for a fill. I was searching the internet for ways to get the most out of your tank and I came across air/gas boosters and one link lead me to Mr. Hollowpoint's video. He has a air/gas booster installed on his fill setup and it allows him to boost the ouput pressure of his tanks when they get low on pressure. For example: lets say you have 2000psi left in your fill tank and your rifle loves being filled to 3000psi, if you have the air booster installed and with a little help of a shop compressor or if your tricky you can install some extra tubing, fittings and a high pressure input - low pressure output regulator you can have a free standing fill station you can bring along with you. Here's a link to Mr. Hollowpoint's video and you can see his setup and how it works.
This is my setup. I only have one tank and in the pic it's set up for using a shop compressor for the low input on the booster pump. I've got more plumbing and a regulator coming in so I can switch it to a free standing unit. I'm gonna make a portable cart for it like in the video but smaller so I can take it with me when I go camping or out shooting with buddies for the day. I'm using quick release fittings to make switching it out a breeze.
These booster pumps aren't cheep but the one I got is the cheepest I found and it's the same one that Mr. Hollowpoint has. It cost me $495.00 new shipped off of ebay. I was going to buy a shoebox but when I saw this booster I thought it would be better for me to get it first before a compressor. I can get my tank filled by my local paintball store and if the owner is there he fill's my tanks for free. Even the big 88cf tank. Man it's good to have friends!