Max. charge rate LiPo One Cell 150mah 3.7 volt cell 5 amps??

[Highway Hilton]

I was looking at the manual that came with my charger today (Thunder AC6) and noticed that it stated that the maximum charge rate for a single cell LiPo battery with a nominal voltage of 3.7 volt is 5.0 amps. They also recommend maximum discharge rate to be no more than 1.0 amp.

And as the cell count increases the overall charge or discharge rates decrease respectfully. For instance a 6 cell LiPo battery pack with a nominal voltage of 22.2 volts drops to 2.3 amp max. charge while the discharge rate drops to 0.2 max.

A charge rate of 5 amps seems awfully high to me for a single cell, what figure do you all charge by so your batteries aren't cooked in the process?

[tombo242]

Hi Highway,

Unless otherwise stated the max charge for any Li-Po is 1C. (Some Rhino's charge at 5C). The charge rate is totally dependant on capacity not voltage or number of cells.

Therefore, if your 3.7V cell had a capacity of 5,000mAh then 5A would be correct. However most single cell batteries are in the lower capacity region. A 400mAh battery would charge at 0.4A.

The quoted 6 cell battery would appear to have a capacity of 2,300mAh as it is charged at 2.3A. The discharge rate seems low it is usually around 1A. But this is not the "In use max discharge". That again depends on the C rating.

This rating is the proportion of an hour that the battery can safely be discharged in. So a 20C battery can be discharged in 1/20 of an hour. The higher the mAh the more amps you can draw in order to discharge in the time scale. A 20C 2,200mAh battery can give (2,200 X 20)/1,000 = 44A. Whereas a 15C 2,200mAh battery will give (2,200 x 15)/1,000 = 33A.

Confusing, but I hope this helps.

[pjdog]

hello Highway Hilton:

I charge my 3.7 volt 1-cell 120mAh 14C batteries at .3a. What's what E-Flite has recommended.

Check you manual that came with you MCX. You will see the charge rate.

Jack

[Highway Hilton]

[admiral]

This might help get your head around it :-

http://www.fmadirect.com/new_applications/CellRatingSpec_KOK1250/index.htm

[tombo242]

That's a good link from Admiral, as always right on the ball.

A "C" is a charge/discharge rating. 1C charge rate is the battery capacity replaced in 1 hour. 1C discharge is the battery discharged in 1 hour.

Assuming that your 150mAh batteries are only rated for a 1C charge, then the max charge current is (150mAh x 1C)/1,000 = 0.15A

I find it easier to convert straight to Ah:
150mAh = 0.15Ah
To fully charge in 1 hour (1C) takes 0.15A for 1 hour.
To fully charge in 1/2 hour (2C) takes 0.3A for 1/2 hour.

It's not easy at first, I think we all had to take several tries at it but we don't always admit it!

It will come I promise.

[pjdog]

Hello again Highway Hilton:

I charge all my 3.7 volt 110 mAh, 120 mAh, 150 mAh 1-cell lipo batteries @ .3a.

Again, that's what E-Flite recommends.

I've not had any problems.

jack

[rajskynetindia]

Therefore, if your 3.7V cell had a capacity of 5,000mAh then 5A would be correct. However most single cell batteries are in the lower capacity region. A 400mAh battery would charge at 0.4A. The quoted 6 cell battery would appear to have a capacity of 2,300mAh as it is charged at 2.3A. The discharge rate seems low it is usually around 1A. But this is not the "In use max discharge". That again depends on the C rating. This rating is the proportion of an hour that the battery can safely be discharged in. So a 20C battery can be discharged in 1/20 of an hour. The higher the mAh the more amps you can draw in order to discharge in the time scale. A 20C 2,200mAh battery can give (2,200 X 20)/1,000 = 44A. Whereas a 15C 2,200mAh battery will give (2,200 x 15)/1,000 = 33A.
but I hope this helps.

Enjoy...

[Highway Hilton]

[tombo242]

rajskynetindia,

Why are you quoting my post without acknowleging me. Your post above is simply a straight copy of mine from further up. In the west this is considered a very impolite thing to do and I have noticed that you have done this in other posts of yours.

PLEASE, let us have some original work of yours. I realise that it is not easy when you are not working in your first language but STOP COPYING OTHER PEOPLES' POSTS!

[tombo242]

Hi Highway Hilton,

Yes, that is correct 4.4A for a 4,400mHa battery on a 1C charge.

rajskynetindia, do NOT copy this post.

[Highway Hilton]

OK either you're pulling my leg here or one of us doesn't know how to use the quote feature. When someone makes a comment further up the line and another person making a post wants to ask THAT individual to clarify they hit the quote button (upper right hand corner) and ask the question.

I was merely asking you to elaborate.

A quote isn't intended to ruffle your feathers. If your feathers get ruffled that easy you have no business on a public forum in the 1st place.

Understand, probably not.....

[tombo242]

Hi Highway Hilton,

Please rest assured that none of my comments on copying were meant for you. Your posts have always been exemplorary.

The person "Ruffling my feathers" was rajskynetindia not you. If you check back up the thread you will see what I mean. My entire post has been pasted in as if it were his. He did not even have the decency to start with "As Tombo said" or put it in a quote as the rest of us do.

I am very sorry if this was not clear, I did try to ensure that my "Don't Copy" remarks were addressed to him and not you. My apologies to you if I did not succeed.

[NMGeezer]

Rajskynetindia has made three posts.
All three were direct copy's of another persons post made to look like it came from him, they were not quotes.
Tombo had a right to get a bit testy

[tombo242]

Thanks for the support there NMGeezer, very much appreciated.