4-Pack of 3.7 volt - 180mAh 45C Lipos for Blade mCX, mSR, and mSR X

Although not made for it, I bought these for my Blade-MCX2 Helicopter. They are a little longer than the factory battery, but work perfectly & give about two to three minutes (roughly) more run time. I've had them for several weeks or more now & they are still going strong. I'd buy more of these if I wanted even more spare batteries, but five total (4 of these plus the stock battery) are enough! The optional, four-port, E-Flight battery charger also works good with these batteries. No Complaints, but I did glue the edges ("side-flaps") of each battery down (to make installing them quicker & easier), using hobby grade super-glue. A tiny drop on each side was all I needed. The batteries came with some velcro pieces that I cut up and used as "stops" to keep the helicopter balanced. I put one short piece on the top & bottom of each battery. I have them set so that the battery goes in & just touches the back of the front body work (opening). This seems to keep the helicopter well balanced with these slightly longer (about an eighth of an inch longer) batteries. The electrical connector matches perfectly.

Use these in my UMX planes/heli's. Work good at first, but after a year they are ok in planes, but can't handle the Blade Nano S3. Not sure any of these small 1s last longer than a year tho.. I'll keep buying these, worth it for the price.

One of the plugs on one of the batteries was a little iffy and wouldn't completely connect, but mostly only mattered when I "landed" a little hard as it would pop off. After a few runs it seems to have adjusted itself and seats ok now.These batteries are performing great so far (maybe ten flights each so far) and charge easy in my  Hitec X4 Micro Ac/dc 1-cell Lipo Charger (44212) . They are *slightly* heavier and larger than the stock battery, but not enough to feel and since the quad has a gyro it effectively auto-corrects for any imbalance that the different shape might cause. Hitec X4 Micro Ac/dc 1-cell Lipo Charger (44212)

I'm using these packs in a stock nanoCPx. Packs are a bit of a tight fit in the little battery holder, but the connector is perfect. I've flown a few cycles through them at this point and they are working great. Flight times are longer than stock for the type of flying I'm doing.I'm still running the stock motors, so do not know how they work with upgraded brushless motors. Do not hesitate to buy these for your nanoCPx

Purchased for use in a Blade Nano QX. A lot cheaper than the B1501S45, but much flatter motor performance. Doesn't last nearly as long either. I flew these batteries back to back. There were some aggressive passes I was making with the e-flite battery at partial throttle that these batteries could not pull out of scraping the ground at full throttle. Fun for screwing around with, but not the best for flight performance or flight time despite the 180 mAh rating.Edit: I just weighed the batteries. The E-Flite 25C weighs 4.2 grams, E-Flite 45C weighs 4.3, Lectron 4.5 grams. All weighed on a kitchen scale good to plus or minus .1 I would venture to say that .2 grams wasn't effecting it's ability to climb and more it's current output.