[nativepaul]

I saw the 60C rating in the title and first post and got quite excited but after reading that it is a surge rating I am not so sure.

I have some questions for Austin should he ever come back.

I have not used a maxamps product before and at the moment it doesn't look like I will at least for the time being, not because of any past experience, feud or loyalty to my chums here but simply because I don't understand the surge C rating format that you have switched to, I followed the LiPo care link that you posted hopping to have it clarified but it does not explain the surge regime there in a way that I can understand either, I understand the constant C and burst C ratings most other LiPos have, the constant C being the maximum current a LiPo can sustain for a full discharge without going over the manufactures maximum recommended temperature (I know many here think that there should be a minimum voltage worked into it too, and while I agree I am too sceptical of the manufactures data to expect it), and the burst C being the maximum pampage that can be drawn for 10 seconds without damage to the cells. but surge I am unsure of as you are the only company that I have heard of using it, is it the same as burst 10 seconds like you might use on a speed run? or a short sub 1 second spike as you might see on initial acceleration out of a corner in a car? if it is the short spike type is it just a single spike or does it allow that there will be a large number of such spikes in a discharge, and is there a base current that it spikes up from or does it go back down to nothing? for example I have seen battery graphs with a 10c constant discharge and a 1 second burst of 20C every 5 seconds, I've seen the same thing with 10c base and a 1 second 30C spike every 10 seconds, 5 seconds of 10C 5 seconds of 20C alternating, all will give different data with the same battery, the surge C rating would mean a lot more to me if I knew the regime in which it was measured.

I am mainly a boater and just have a couple of cars as sometimes I don't want to drive to the lake which is a fair distance for me and find it easier to drive in the road outside or if its raining (and I live in England so its not rare) I can chuck my buggy out the door and drive in the garden drom the warmth and comfort of my living room, the eagletree graphs of my boats are very different to those of my cars, the cars averaging about 25A but mainly in very short spikes of about 120A from a base of less than 10A, and I have 3 types of boats minis that average about 20A from a 20A base but with spikes up to 30A and down to 10A as the prop comes out of the water after a wave unloads revving the motor up then re-immerses deeper than normal loading up, endurance race boats that pull an average of 60A with peaks up to 100A and down to 40A and sprint boats that pull 120A average, spikes over what my eagletree can handle but I would guess around 200A and down to 80A How does this relate to your surge rating? would your 60C surge rated 5250 battery be up to the enduro race and sprint setups in a 1p configuration and will the 2200 take my mini setup?

You list 4 reasons continous C ratings are irrelevant in the battery care page you linked to all of which are can be overcome, most without much effort.
* Your entire run time would be less than 90 seconds.
Sprinting is 5 laps, its over in about a minute so 90 seconds is plenty of runtime

* You would melt the RC plug attached to the pack(Deans, Traxxas, Tamiya, etc).
I haven't seen a Tamiya conector for about 15 years even with modified 540motors and NiCads they were melting, I saw the last deans about 10 years ago when BL came on the scene and they started melting, dont know anyone that tried Traxxas as they look as bad as deans, I use 6mm bullets for everything and have since the high capacity 20C LiPos came out, 4mm bullets were enough till then.

* The bullet connectors on a hard case pack would melt out of the casing.
I wasn't adverse to cutting the cases of TP 40C packs when they first came out and were only available in hard cases, although this is the tricky one, you have to be very careful and its not for everyone.

* Even 12awg noodle wire would get too hot to touch.
I couldn't agree more and seeing the 12awg cable in the first post was the thing that first gave away the fact that these may not be the 60C continuous cells that I was hopping for and quite frankly I don't see a place for 12g wires on any 5Ah 20c+ battery, since the first big capacity 20C cells came out I've used Flightpower, Thunderpower, Nue Energy, Kokam, Zippy and Turnegy cells, all of them apart for the Zippys and the thunderpowers came with 8awg wires, the TPs came hard cased with no wires so I added 8awg and the Zippys I replaced the 12awg they came with for 8awg, (Kokams come with 8awg right down to the 1800s I use in my mini although I think its overkill for this size battery)

Some of us do run at high currents and I find the constant and burst C ratings useful, I often run my sprint setup which is 30C continuous with 40C peaks and occasionally run SAW which is about a 5 second burst 10 seconds of low power then a 5 second burst and another 10 seconds of low power per run which is quite close to the burst spec. so personally I would prefer that you included them as well as helping us understand the main surge rating you are now using, you mentioned that you changed the rating system not the packs, what constant and burst C ratings do these packs have under the old rating system?

I very much like the fact that you offer a warranty on batteries with a surge watt rating higher than the surge watt rating of the motor used but unfortunately I only have 1 CC or Novak motor a mamba 7700 I use with 2s A123s and I have 10 packs that I made from a pair of dewalt drill batteries so hopefully I have enough to last me a lifetime in that car, and none of my other motors have a surge watt in the documentation they came with, it says you have a list available if I call Maxamps but I have a fair few motors not all of them popular in the states, they may be hard to find on your spreadsheet or need calculating, could you tell me here what the surge watt ratings of my motors are or maybe if its a calculation you could tell me the formula and I can go through the list at my pleasure then email it back to you for confirmation? I Dont want to call as its an international call for me and I I anticipate it costing me as much for the phone call as a battery would cost. I have in order of size, motor then cell count in case you need that:-
Hacker b20/18L s3/4s
Mega 16/15/2 2s/3s
Mega 16/15/3 3s
Neu 1110/1d 2s
Mega 22/20/1 2s
Mega 22/20/2 2s/3s
Mega 22/20/4 3s/4s
Mega 22/30/2 4s
Mega 22/30/3 6s
Neu 1509/1.5d 2s/4s
Hacker 9L 4s
Hacker 12L 4s
Feigao 6XL 4s
Feigao 8XL 4s
Neu 1521/2.5d 6s/8s
Lehner 2280/11d 12s
Thanks for your time Austin.

Paul