David Maffucci Review of Maxamps MV Packs
 

Dear MaxAmps.com,

Just wanted to drop you a note about how pleased I was with the performance of the new MV5250 LiPo battery pack. I was racing at my local track during one of our points series races recently and a representative from MaxAmps.com showed up with a slew of the new MV5250 cells in a variety of configurations. He was letting us racers try them in our own vehicles under real race conditions to see how they compare to what we are used to running. Since I run Electric 1/8th buggy and truggy I figured it would be a perfect test of the packs. I quickly and easily assembled the MV cells into a 4S configuration. I was very impressed with the cells themselves as well as the connectors, gauge of the wires and soldering of the battery connector. Once assembled they were a perfect fit into the stock battery tray on my Losi 8e 2.0 buggy and Losi 8Te 2.0 truggy. There were no clearance issues with the buggy body, something which has been an issue on some other higher capacity packs. When assembled in the 4S configuration, they were really no bigger or heavier than other packs of similar capacity that I run. Matter of fact, they felt very compact and light for a 5250mah capacity pack. I strapped them in and headed out for a qualifying race.

As great as the packs looked and felt what really makes a pack special is the performance. Our qualifying races are only 6 minutes long so I knew I had plenty of capacity. I headed out and ran as many warm up laps as I could before the racing began. No matter where I was on the track, I had the power to clear every jump, roost out of every corner and scream down the front straight. I ended up TQ'ing buggy with the MV packs. The main race was when I really pushed the MV5250's to their limits. We run a 12 minute A-Main but I was confident in the MV5250's so I took a few warm up laps and lined up for the start. At the tone the power was everything I expected. As the clock ticked down, during those last few minutes, with some packs I have trouble clearing the big triple on our track but powered by the MV5250, my Losi 8e 2.0 had no trouble clearing that jump from the first lap to the last. I'm happy to say that I sailed to a win in buggy with the MV packs providing the juice, finished a close 2nd in truggy too.

After the races I was able to watch the MaxAmps.com rep balance and then charge the packs. It was simple, effortless and foolproof. Seeing the same cells used in different configurations for different vehicles really made a lot of sense. With one purchase you could run 2S in your Short Course, 3S in your 4x4 Unlimited SC and 4S in your electric 1/8th buggy or truly. I was very impressed by the quality of the build, the ease of assembly and of course the best part, how well they worked out on the track under real race conditions. Keep up the great work and thanks for continuing to offer solutions to make RC better!

David Maffucci

http://www.maxamps.com/newimages/mvbatteries.jpg

Thought it interesting to posts as he's a regular on here...

The RC Driver review from David Baker also came out very positive on these...

Its looks like the connection design looks like it has been improved - I think that these could work very well for advanced users but am concerned about how the cells will cope over time as they get out of cycle with each other.

Also worried about the charging method - reconfiguring to parallel for charging risks combining a discharged and charged cell together. I'd hate to see someone someone mix cells together that are at different levels. Rapid equalization of cells like that is going to be very dangerous.

In addition people need to be aware of their chargers limits with this setup - Most chargers have a 5, 6 or 10amp limit. So if you now have a 1p 20kmah pack and a 5amp charger its will mean you can only charging at .25C (4 hours) vs 1C as a 4p 5k mah pack (1 hour).


*** Comments about pricing or general bashing will be deleted ***

I hope MA didn't patent the connection theory. To me its a first step towards a reconfiguable pack, and hopefully, an easier method of changing out packs in the trucks.

looks like they dont have balance taps, so your only option would be to charge them in parallel if you wanted any kind of balance between the cells. not very efficient and kind of slow as well. not to say it wont work, but what happens when a discharged cell is paralleled with a partially charged cell? like the idea but i want to see how it plays out in the long run.

I can understand the parallel thing for simplicity of the wiring. But some sort of plug in balance harness is needed really. How else are you going to be able to recognize a bad cell? Definitely not for the inexperienced user.

Actually, a selling point told to me by Austin is that he has taken a fully discharged cell, and fully charged cell, hooked them in parallel, and within 5 minutes they were in balance with each other with no harm done. Or so he claimed.

I was the winner of the slash 4x4 because I guessed that this product was coming out the first day he posted it on RCU. (of course he didn't tell me till they were released). He also included a 2S configuration of these packs.

I've broken 1 of the series connectors, and 1 of the plug adapters. They were superb and sent me replacements of each, as well as the updated parallel charging adapter (much better than original).

I run it in my 2wd slash since I sold the 4x4 to help fund a savage flux. Is the battery pack good? yes, it is very good. Can I tell a discernible difference between it and my turnigy or my zippy? no. It does fit very nicely, and their support has been awesome and same-day.

They stay perfectly balanced all the way to the end, and charge up nicely. I use a lipo sack for a little bit of added safety since I live in the dorms at a university. I have to say the parallel charging is tough to fit in my small one, but not bad in the larger one I have. They nice to store in them without wires though.

I wrote a review on the site as Austin wanted me to, but since I wasn't super enthusiastic and solely praising them it was never added :whistle:


Hooking them up in parallel balances them. But I wouldn't want to have one go bad or something and then hook it up to some good ones in parallel....might not be pretty. I would agree that these probably shouldn't be for a beginner, but anyone with electrical experience should be pretty well off. Of course there is that ever so lacking common sense thing that really helps too....

I'm not familiar with the + & - plugs (the photos don't show enough detail for my feeble eyes either) but one would hope it's not possible to cross wire them...

In winter, most if not all running I do is at night, I'd hate to create my own light source by shorting cells...

I'm RCM smart(best of the best!) and I will avoid the MV packs because of their complexity.

One would have to constantly rotate cells and log their use to keep cycle numbers even.

I feel if you can't afford a dedicated pack for each vehicle you have too many vehicles!

I am glad that MA is trying new things. Their next idea might be a winner!

Problem is they are still of no use for me. Too many different sizes and needs to fit what I have. Plus, the premium paid and the effort to properly manage these cells outweighs any benefit I see the bringing.