For direct P1 replacement pack (brick) I use Hobby King Turnigy 20C 2200mAh. They can ship from USA and usually cost me about $10ea. Last 2qty were a little over $26 shipped.
https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=59014
Great battery for the money and fits P1 with plenty of room to spare. I dunno about all the battery compartment mods. I just run stock P1 with 2.2Ah bricks for now.
I’m new to P1 but very experienced with RC Lipo and here’s my thoughts about longevity:
Puffing is never good and I don’t recommend pricking the pouch to remove the Hydrogen gas. Remember the Hindenburg? Same stuff inside puffers. I’ve done it and it’s worked but there’s just so many ways a person can go wrong I can’t recommend doing it.
If mildly puffed, try placing it in the freezer (around storage charge or lower will help) and it should improve puffiness? If it does, while it’s cold wrap the brick with fiber reinforced packing tape. Use layer of clear (Saran) plastic wrap underneath the tape.
In fact, applying reinforced packing tape when new is not a bad idea either. It can help maintain compression which is inherently difficult with any pouch cell format.
However, you can do a lot to prevent puffers by avoiding deep discharges and being mindful of storage charge.
Deep discharge - we all wanna fly as long as possible but when RC Lipo is @ low SOC (state of charge) you easily can cause/waste a lot of excess heat which = irreversible damage. My personal habit is to best minimize current draw after about 1/2 normal flight time.
Know your flight times with various payloads. Better yet, ditch the little toy charger that comes with these birds and buy a real RC Charger so you can actually know how much capacity your packs consume per average flights.
Once you have those numbers established set a timer whenever you start the motors. Don’t hesitate to bring the bird in and swap out for a fresh pack when you’ve reached a conservative flight time.
Another advantage of a real RC charger is that you can recharge at much higher rates. High rate charging is nowhere near as bad on the cells as over discharge and storage @ full SOC. You can safely recharge a healthy brick in almost the time it takes to empty 1-2qty in flight. 4-5qty bricks and you can fly all day if you want.
Storage charge should definitely be applied if you won’t be using the bricks in an upcoming 24 hr period. It’s not too bad to leave ‘em full SOC for a day but any longer you should drain them down to around 50%. Leaving RC Lipo @ nearly full SOC for more than 24 hrs is asking for significant cell deterioration. This is often a reason for puffing, IMO.
Here’s the safety deal about puffing. If/when they swell up like a balloon or inflated rubber glove there’s a very real risk of cell tabs shorting and creating sparks which then causes internal heating, more puffing and can quickly result in very nasty consequences.
Dramatic puffing is most likely how Lipo fires get going in storage with no equipment draining or charging them. I’ve taken a lot of 5Ah bricks apart and reworked them - it’s easy to see how the cell tabs can short once the pouch goes balloon shape.
Take puffers seriously and remember the Hindenburg? Now imagine the Hindenburg with it’s own source of ignition (sparks) and hot Toluene solvent to keep burning after the hydrogen is quickly consumed?
Yeah, they’re awesome cells and revolutionized the RC world but take them very seriously. Store only where you would build a fire. Get some good charging equipment and better understand what all the voltage, amperage, IR parameters really mean. You’ll be glad you did….