Lipo Question/help

[Flying Scotsman]

More googling found this...

"For example, two 1,000 mAh Lithium Polymer cells with 15C continuous discharge ratings that were wired in parallel would create one 3.7 V pack with a 2,000 mAh capacity and could support an application where the total current draw was up to 30C (30 Amps). "

Link <-- Pulled directly from a lipo battery website!!

Again, it contradicts. Please show your sources for your info.

That is exactly what I stated!!!!

When you parallel 2 2S1P 20C 1000 mah 20C batteries = 40 amps @ 7.4V
2S = 7.4V........2X3.7V
2x20 amps=40 amps

Please note that you should not draw 40 plus amps continiuously for 2S2P 1000mah 20C on your set up as battery will go poof in a short time. Do not use Max amps of your motor as a guideline for Battery and ESC max because if you overprop your boat the amps will be way higher.

Doug

[Diegoboy]

That is exactly what I stated!!!!

When you parallel 2 2S1P 20C 1000 mah 20C batteries = 20 amps @ 7.4V
2S = 7.4V........2X3.7V
2x10 amps=20 amps

Please note that you should not draw 40 plus amps continiuously for 2S2P 1000mah 20C on your set up as battery will go poof in a short time. Do not use Max amps of your motor as a guideline for Battery and ESC max because if you overprop your boat the amps will be way higher.

Doug

Thank you Doug. It's just that I was looking for a cut & dry answer. like "Yes, SJFE was right" or "No, SJFE was wrong" The link almost states that when it said 15C + 15C in parallel = 30C. Coming from a Lipo retailers website makes it concrete, rather than just an opinion.

[Mich. Maniac]

has anyone heard from Mr. Hill or battlepack. he used to be great at these questions

[Flying Scotsman]

I got my figures wrong. Please see corrected amp rates or C for two 2S1P in parallel. As in my post prior to previous answer

Doug

[SJFE]

He is the first preson to tell me this. I just couldent remember the exact formula he gave me..and lost the text file.

[NorthernBoater]

More googling found this...

"For example, two 1,000 mAh Lithium Polymer cells with 15C continuous discharge ratings that were wired in parallel would create one 3.7 V pack with a 2,000 mAh capacity and could support an application where the total current draw was up to 30C (30 Amps). "

Link <-- Pulled directly from a lipo battery website!!

Again, it contradicts. Please show your sources for your info.

Note that when they are saying 30c in that quote, they are referring to the 1000 mah pack. Do not get that confused with the 2000 mah later in that quote.

[SJFE]

Do not get that confused

Oh it's way to late for that my friend

[Flying Scotsman]

Note that when they are saying 30c in that quote, they are referring to the 1000 mah pack. Do not get that confused with the 2000 mah later in that quote.

Northern Boater you are wrong the google statement is correct as are the figures I have stated.

Doug

[NorthernBoater]

More googling found this...
Please show your sources for your info.

Here are two packs, one is 3s1p and the other is 3s2p, note that they say the same c rating for both.
3s1p -- http://www.maxamps.com/Lipo-3000-111-Pack.htm
3s2p -- http://www.maxamps.com/Lipo-6000-111-Pack.htm

[Diegoboy]

what you posted is based on the cells in each pack.
We are discussing running multiple packs of the same rating.
Take 2 of either pack you posted, run the two in parallel, you will double the total "C" and the voltage remains the same.
Take 2 of either pack you posted, run the two in series, you will double the total Voltage, and the "C" will remain the same.

[NorthernBoater]

what you posted is based on the cells in each pack.
We are discussing running multiple packs of the same rating.
Take 2 of either pack you posted, run the two in parallel, you will double the total "C" and the voltage remains the same.
Take 2 of either pack you posted, run the two in series, you will double the total Voltage, and the "C" will remain the same.

The 6000 mah max amps packs are just the 3000 mah packs paralleled. If you assume that you double the total "C" when paralleled, then you can not say that you doubled the mah capacity.

[Diegoboy]

"Parallel Configurations – Multiple like Lithium Polymer packs, unlike NiCd and NiMH, can be wired in parallel to effectively create one, larger pack with the combined capacity of both packs. This also has the beneficial effect of splitting the current draw between each pack and thus enabling a higher current draw."

That is a direct quote from the previous mentioned link.
It clearly says effect of splitting the current draw between each pack.
It also says enabling a higher current draw

Show me otherwise in black and white. not just 2 different packs. When combining multiple packs in parallel.

EDIT: Wait a minute... That quote is also talking about cells wired internally. Maybe you're right!
I don't know, I'm just standing on the shoulders of giants... que my signature!

[Doug Smock]

The 6000 mah max amps packs are just the 3000 mah packs paralleled. If you assume that you double the total "C" when paralleled, then you can not say that you doubled the mah capacity.

FORGET about Max amps and THEIR C rates on 2p packs for a second. It is confusing you. And I see how it could.

Now, go back and reads Doug's post. He is correct, as was SJFE and Diegoboy.

When YOU (KEY WORD) parallel cells. The capacity and C rate double.

Its dark on the darkside huh?? LOL


Doug

[SJFE]

Crap yeah it is...All I know is i'm about 30 minutes off buying 8 of these packs. If it works I'll have found a cheap way for some great sport running. If it don't...I'll have takin one for the team...someones gota do it. I just needed a check on my math. Thanks fellas.

[Diegoboy]

Thank you Doug (both of you) for clearing that up. I was beginning to get confused! lol