Turnigy LiFEPO4 packs

[sikeston34m]

OK, back on topic here.

Just received my packs, and they look good.

All cells are right at 3.33 volts and are within .003 volts of each other.

After soldering a few connectors on, I'm running a limited discharge test.

My MRC Superbrain 989 will do lead acid. Well it just happens that is a 3.6 volt per cell cutoff, just like the Lifepo4 chemistry.

These packs were nearly charged upon receipt, but I went ahead and topped them off until the charger dropped to .5 charge amps.

It's already dark outside here, so E Revo runs will have to wait until tomorrow, but I can tell you this.

On a 10 amp constant discharge, cell voltage at the balance lead, drops to 3.25 volts per cell at the beginning of the discharge cycle.

I'm using an Extrema Balancer with PC Software for voltage reporting.

Discharge at the 1000mah mark sees volts per cell at 3.21 volts after 7 minutes.

Discharge at the 2000mah mark sees 3.19 volts per cell at the 15 minute mark.

At this point my discharger is getting hot. LOL It has tapered back the amps of discharge to 7 amps. Dang it.

At 2300mah's of discharge, it tapers it back to 5 amps. The discharge side of this MRC is wimpy. LOL

At 3000mah's of discharge, 5 amp draw shows 3.15 volts per cell.

Even though it's a small discharge rate, the discharge curve appears to be pretty flat.

Spin the Clock forward to the next afternoon.

I just took my E Revo for a run. MMM ESC, Medusa 36-60-1500kv geared 22/40, being powered by 4S Lifepo4.

When I sat the truck down and stabbed the throttle, it charged off, then just stopped. I was already on the LVC, because it was still set at 3.2 volts per cell for the Lipo..........dang!

I quickly unplugged the ESC and plugged it back up. It beeped 3 times and told me that it was now counting 3 Lipo cells for the LVC.

Hmmm..........9.6 volts Total LVC = 2.4 volts per cell. Perfect!

These packs are punchy! The truck wasn't as anxious to backflip like it was on Lipo, but alot of time was spent on the spoiler and it would point the front end to the sky almost at will.

Top speed was much better than I expected, even though no gears were changed.

I zipped around the yard, pulling wheelies and slinging dirt for 20 minutes, before it got on the LVC of 9.6 volts.

At the end of the run, the cells had settled back up to around 3.2 volts per cell and were all within .004 volts of each other.

Pack temperature was barely warmer than when they were put in the compartments.

I have ran 4S2P A123 cells in the past, on similiar setup. I believe these are holding voltage better under a load.

Plans are to hook these up 4S to a lead acid charger I have. Then test their fast charge ability, while monitoring individual cell voltage.

A Typical Lead acid charger has a 14.5 volt charge cutoff. This is perfect for 4P!

Then I can charge at 20 amps. I will report more as testing continues........

[lutach]

Not bad for rejects.

[sikeston34m]

Originally Posted by lutach

Not bad for rejects.

I'm not "giving" that "other" company any of my money, but I would just about be willing to bet, these ARE the same cells.

Identical size and weight!

[Unsullied_Spy]

Originally Posted by sikeston34m

Identical size and weight!

Yeah but what about the ratings? The MA ones are rated better so they must be superior. Oh yeah, they're also factory fresh cells and made to order. And water proof

[lutach]

Originally Posted by sikeston34m

I'm not "giving" that "other" company any of my money, but I would just about be willing to bet, these ARE the same cells.

Identical size and weight!

What are you F****** serious, I said they were factory rejects and will never perform like my packs....Now go buy my packs (I'm in Jason's mode btw).

So, does anyone here have the other life pack from you know who?