GSMnow
07-20-2008, 12:32 PM
After some testing on my aging (over 60 cycles) Max Amps 3000 HV packs, I have certainly noticed a little loss of performance. They are just a bit too weak to handle my Mamba Max powered XXX-4 and when I pull them out of the car at over 150F run after run, I knew it was time to get something better suited.
I have seen the Losi 2S 5000 pack going for $99.99 and figured I would take a chance on it. With a 20C rating it should take 100 amps, vs the 60 amp rating on my little Max Amps ones. When I got the pack and checked it, it was at 7.78 volts and in perfect balance between the cells. SO far so good. I put it on charge at 4 amps, a little less than 1C. It took just over 2000 mAh to top it oiff, so it was just over 1/2 charge, good job Losi. I have heard stories of other packs being delivered well under 3 volts per cell, so this was a good sign. I did a very quick shake down just to see if it had good current. Wow, it just kept spinning the slipper clutch all over the place. I topped it back up and tried to get the slipper a little tighter. I also put the data logger in the car.
The slipper is still not holding good enough, but what I saw is already impressive. NOt only was I seeing sustained 55 amps plus pulls, but at that current, the voltage was holding 7.4 volts for 407 watts. This is holding voltage better than when I run both of my 3000's in parallel (7.4 volt 2S2P 6000 mAh) which is quite amazing. I pulled the whole slipper out of the car and re-built it and tightened it down so hopefully I can hold a bit more now. When my Max Amps packs were fresh, I did top 75 amps with the 6000 setup, so it will be interesting to see if this pack can do it too.
Before I worked on the slipper, I drove it for over 10 minutes, and it was still pulling strong with no noticeable loss in power and the pack was barely warm. It took just 2600 mAh to top it off which sounds about right, I was getting 12 minutes on the Max Amps 3000's. I hope to hit the track with it today now that the slipper seems to be holding better.
I have seen the Losi 2S 5000 pack going for $99.99 and figured I would take a chance on it. With a 20C rating it should take 100 amps, vs the 60 amp rating on my little Max Amps ones. When I got the pack and checked it, it was at 7.78 volts and in perfect balance between the cells. SO far so good. I put it on charge at 4 amps, a little less than 1C. It took just over 2000 mAh to top it oiff, so it was just over 1/2 charge, good job Losi. I have heard stories of other packs being delivered well under 3 volts per cell, so this was a good sign. I did a very quick shake down just to see if it had good current. Wow, it just kept spinning the slipper clutch all over the place. I topped it back up and tried to get the slipper a little tighter. I also put the data logger in the car.
The slipper is still not holding good enough, but what I saw is already impressive. NOt only was I seeing sustained 55 amps plus pulls, but at that current, the voltage was holding 7.4 volts for 407 watts. This is holding voltage better than when I run both of my 3000's in parallel (7.4 volt 2S2P 6000 mAh) which is quite amazing. I pulled the whole slipper out of the car and re-built it and tightened it down so hopefully I can hold a bit more now. When my Max Amps packs were fresh, I did top 75 amps with the 6000 setup, so it will be interesting to see if this pack can do it too.
Before I worked on the slipper, I drove it for over 10 minutes, and it was still pulling strong with no noticeable loss in power and the pack was barely warm. It took just 2600 mAh to top it off which sounds about right, I was getting 12 minutes on the Max Amps 3000's. I hope to hit the track with it today now that the slipper seems to be holding better.