Inexpensive 4s LiPo Comparison Sheet

[MetalMan]

Lately I have been working on a comparison chart of different 4s LiPo battery setups in the range of greater than 43amps continuous. This chart includes a number of calculations that I have made based primarily off of discharge graphs, but I have also used some manufacturers' data. These numbers are pretty accurate, or at least enough so for my purposes.

Packs with manufacturers' ratings:
-CS 14.8V 3.15Ah x2
-TrueRC 7.4V 4.4Ah x2 (most likely not very accurate for burst rating, the bold is to give my input)
-EP 14.8V 4.4Ah
-EP 14.8V 5.4Ah
-EP 14.8V 6.6Ah

The packs that have long lengths would be cut up and rewired into 2 packs.

Many of the packs/cells are/use narrow airplane-type cells, which are appealling to me right now because I could make a chassis to fit these narrow cells. People doing nitro-to-electric conversions that have considered not using battery cups might find these cells to work well, especially since compared to wider cells they will fit onto mud/rock guards better. My current personal choice is the "HypIon 3.7v 2.1Ah x8", since the price is good, the power is good, the cells themselves are common and known to be good, and it would make a lightweight pack.

Two more expensive packs were thrown into the mix for comparison purposes. They are the "TP 7.4V 4Ah x2" and "ProL 14.8V 2.1Ah x2". I feel safe in saying that the "ProL 14.8V 2.1Ah" pack and the "HypIon 3.7v 2.1Ah" are the same cells, which might be the same as the TP 2100s and several other brands.

If there are any questions at all, feel free to ask them. I'll do my best to answer them. Also feel free to ask about other inexpensive packs, since if I feel they are a viable option for this list, I will add them.

[BrianG]

Nice collection of data you have there! Must have taken some time to compile all that.

Might I offer a suggestion to make the numbers more meaningful? Enter the numbers into Excel and create graphs. As they say, a picture is worth 1,000 words. Maybe a collection of bar or line graphs to show the relative merits of each brand for a particular category. Then, maybe a scatter plot (performance on one axis and price on the other) showing the best "bang for the buck". You could easily turn this into a buyer's guide and then sticky it. :dft003:

[MetalMan]

That's possible. First, I gotta install Excel (I do have it). Then, I would need to enter all this data into Excel. After that, I would need to learn how to do graphs.

If you're wondering how this chart started: One day I thought it would be a good idea to make a chart of comparisons of different characteristics of each pack to find one that would be optimum for my budget. Over the past 2 weeks or so I've been modifying the values of some numbers, adding in new entries and removing entries that wouldn't be good choices.

[Serum]

That's one fine list MetalMan!

[coolhandcountry]

The adobe was fine for me. If you did it in excel i wouldn't have been able to look at it cause I don't have excel. Thanks metal man.

[Gustav]

Those 2.1Ah cells look impressive,particularly the power:weight.

[BrianG]

Originally Posted by MetalMan

That's possible. First, I gotta install Excel (I do have it). Then, I would need to enter all this data into Excel. After that, I would need to learn how to do graphs.

Graphing is really not that hard. The wizard steps you through many steps. As long as the user understands what the graph is supposed to represent, it will turn out fine. But yes, you DO need to install it. :dft012:

Originally Posted by coolhandcountry

The adobe was fine for me. If you did it in excel i wouldn't have been able to look at it cause I don't have excel. Thanks metal man.

I don't know what he used to create his initial PDF, but there's a cool free program called PDF995, which is just a printer driver. This means that it installs like a printer and whenever you select the 995 "printer", it prints to a PDF file instead. Of course, this assumes MetalMan is using Windows...

[MetalMan]

I use Corel WordPerfect (a Microsoft Word competitor), and it has the feature to export to PDF. So, that's what I did :). I'll work on getting it Excel'd (:)), and post what I can when I can. My English teacher hasn't been very nice lately with our work load... (then there's tennis too).

[BrianG]

Well, I'm kinda laid up right now due an ankle issue, so I guess I could take a stab at it and send it to you. I'll see what I can come up with...

Incidentally, OpenOffice has a similar "export to PDF" feature, but I'm not sure their version of Excel will do charts the same way. MS Excel uses VBA for its macros and stuff, and I'm wondering if VB is used in the graphs.

Do you know if the max amps 4 Ah cells are the same as the TP 4Ah cells (or at least the same specs)? If so, Im glad I bought them.

[MetalMan]

TP doesn't make 4Ah cells, they only parallel 2Ah cells. The Maxamps 4Ah cells are the same as Dualsky and X-Power 4Ah cells. I think there are other companies that use these cells as well, but my mind is drawing a blank on them.

I found a cell that fits perfectly into an E maxx battery compartment.
3200 mah 15c. $14.50 a cell (does not include shipping from hong kong)

Ok measurements of my IB 6 cell pack 7.2v 5 1/4" long, 1" thick, 1 3/4" wide.

These cells are (rough conversions) 5 1/4" long 135mm, 1 3/8" wide 35mm, 1/4" think 7.5 mm.

So a 3200 mah 2s would be 7.4 v and 1/2" think $$$29$$$ plus shipping
a 6400 mah would be 1" thick 2s2p $$$58$$$ plus shipping.

We need to get together and order a bunch of these to get a better rate and cheaper shipping. I used to import lipos for planes. Did this for a few years so I know how it works.(My major retailer was www.3dfoamy he still has a few if you want to check out my story Great Things batteries)

Who's in with me. I am not in this for money but to get some batteries for a little cheaper.

Or get RC-Monster to get a bunch of these.

Dan

[MetalMan]

How good are these cells? Have they been tested? If they hold up, this would be an incredibly cheap option! ($116 for 4s2p - 14.8v 6400mah 15C)

You can look for your self.
I emailed them for a discharge graph.
Part # TR7535135P15HR
I was told the 15 HR was the C rating but I am confirming as we speak.

http://www.tronicshz.com/main.php?sLAN=en

[MetalMan]

Based on how Tronics 2100mah 15C cell has performed, these cells might not be worth it. Maxamps sells the Tronics 2100mah 15C cells as their own, and many airplane users reported a large drop in performance after about 30 cycles, even at moderate discharge rates.