Savage Flux Eagle Tree Data

[fastbaja5b]

Considering I am using a 100 Amp Eagletree logger, I suspect there are some inaccuracies as the voltages are recorded at Amps outside the ideal range.

That said, my other Harris pack got to 6.38 in similar conditions, and a Reedy 20C 7.4V 5000mah hardcase Lipo got to 5.89 on a brief drop, so that to me reinforces the assertion that you need a battery rated for at least 125A in the Flux (given a high amp spike of 119)

I put the same Reedy battery straight into my Slash VXL (no top up charge) and got a voltage drop to 6.89 volts under a 79 Amp Load there.

It's not a perfect measurement, I'm sure the eagletree's use of fake deans doesn't help, wire lengths etc etc but it's all learning.

If anyone wants a copy of the log files just drop me a PM, happy to share!

[J57ltr]

I don't see any problems with your data, the more amps you pull the more the voltage drops. That's a lot of amps and there is no way that the voltage is going to stay at the same level. I see a 4S A123 pack drop to 6 volts @ 175 amps. Heck even on my 60 amp power supply I test amplifiers with drop voltage in short bursts 2-3 volts @ 35 amps or so, that's just the way it is. A goes up V goes down. Is it going to hurt your batteries? You haven't exceeded the 30C of the battery so I would doubt it. Your run just looks like you were just doing a few high speed runs. I don't think your eagle tree is an issue at all. I have strapped my Fluke meter set to record and gotton the same voltage values as my eagletree, and they both have about the same sample rate 100ms.

Jeff

[zeropointbug]

I wouldn't say 3.2v/cell at ~24C is fine, especially considering the rated 30C. They are obviously over rated, or my new Hyperion G3 packs are underrated, because I get 3.7v/cell at ~22C discharge, they are rated for 35C/65C.

[Mentat]

Originally Posted by zeropointbug

I wouldn't say 3.2v/cell at ~24C is fine, especially considering the rated 30C. They are obviously over rated, or my new Hyperion G3 packs are underrated, because I get 3.7v/cell at ~22C discharge, they are rated for 35C/65C.

How do you figure the true Discharge ratings? I wanted to see what my Zippy packs are doing and these Turnigy packs

[J57ltr]

Originally Posted by zeropointbug

I wouldn't say 3.2v/cell at ~24C is fine, especially considering the rated 30C. They are obviously over rated, or my new Hyperion G3 packs are underrated, because I get 3.7v/cell at ~22C discharge, they are rated for 35C/65C.

I'm kind of new to this stuff, but isn't the C (or Capacity) rating just the amount of current the pack can sustain without damage. To me it has nothing to do with how well the voltage is going to hold, rather how much current it will put out without damage. I have seen some voltage/current charts for some batteries but I haven't seen them listed for 30C and 60C rates.

The ones I have dropped quite a bit. I agree about some over rating and some underrating, but there may be some differences about what is over/ underrating. One engineer may say that at full discharge the cell must not drop past “x” value, another may specify a different value. This industry is fairly new so very few standards have been developed.

Jeff