HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 30, 2010, 06:16 PM
Registered User
Joined Dec 2009
42 Posts
Quote:
Originally Posted by SteveM732 View Post
" A capacitor on the output of the power supply would help clean up that noise" .
Steve - Can you recommend the specs for a capacitor that will do the job.

Thanks!!
drsmith751 is offline Find More Posts by drsmith751
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 30, 2010, 06:18 PM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,634 Posts
Quote:
I wasn't planning on using the batteries as the sole power source - just using them inline with the PS to help buffer the demand from the PS. Still a bad idea? (essentially what drsmith751 was going to do)
You are talking about pulling approx. a 7 amp. load on a battery rated at 7Ah .and I bet that 7Ah rating is based on a 20 hour discharge rate. Chances are at 1C discharge rate it is less than 2Ah and for decent cycle life should never dischaged more than around 2 Ah. if that. Your 24.7 V power supply will not evev charge the Pb over approx. 40% state of charge so you really have perhaps 3Ah at best and you are starting off with them below the level they should ever be discharged to.

Specs.. on a 12V 7Ah I happen to have here.
Charge to
Standby use 13.5 to 13.8
Cyclic (what you are proposing) 14.0 to 15.0 volts initial current 2.1A max.

Chart here: Colored about 3/4 down

http://www.windsun.com/Batteries/Battery_FAQ.htm

12.3volts indicates approx. 70% charged

Charles
everydayflyer is offline Find More Posts by everydayflyer
Last edited by everydayflyer; Aug 30, 2010 at 07:55 PM.
Reply With Quote
Old Aug 30, 2010, 10:16 PM
Registered User
United States, WI, Milwaukee
Joined Sep 2008
777 Posts
Have been doing some charging since I got the PL8. Been charging 3S 2250 25C batteries. I have tried generic accurate charge and generic faster charge using Auto 1C charging. Like I have read on here it definitely under charges at about 1.4A per pack, both as single packs and parallel (2-3 packs).

I don't charge plugged into the computer since I prefer to charge outside in a fire safe container. But when I went to work on a custom preset, I got warning messages about stored errors that all reported over-voltage. I sent that on to FMA.

After reading on here, instead of creating a custom fuel table, I'm going to make a preset using manual charging. I am going to use the "generic high power" as my base to work from and copy that to a preset.

My questions are:
1) The best way to limit the voltage of the cells to indicate a charged state to the charger? Since there appears to be over-voltage charging on the packs I want to alter the "full charge" voltage to lower than 4.199.

My thought for the answer is to "check" the "Advanced Properties" for my new preset (my copy of "high power") go to the "fuel tab" and alter "fuel table 100%" from 4.199V to something lower like 4.15V (or possibly lower and creep up on a higher value later). Does this seem like a correct solution?

Another answer may be for me to change the "C/?" Termination setting on the "Termination Tab"?

2) When setting the manual charge current, am I setting it per pack since it asks if I'm parallel charging and how many packs OR should I be doing the math (2.2 Amps * #of packs)?

My thought here is to use the "per pack current" (i.e. 2.2 Amps in this case) and then tell it how many packs I'm charging. (this assumes that if I'm charging let's say 3 packs in parallel then by specifying a current of 2.2A and 3 for number of packs it will charge at or near 6.6A).

Thanks in advance,

Mike
Brownie433 is offline Find More Posts by Brownie433
Reply With Quote
Old Aug 30, 2010, 11:23 PM
President, FMA, Inc.
Tim Marks's Avatar
Joined Mar 2008
1,051 Posts
Quote:
Originally Posted by Brownie433 View Post
Have been doing some charging since I got the PL8. Been charging 3S 2250 25C batteries. I have tried generic accurate charge and generic faster charge using Auto 1C charging. Like I have read on here it definitely under charges at about 1.4A per pack, both as single packs and parallel (2-3 packs).

I don't charge plugged into the computer since I prefer to charge outside in a fire safe container. But when I went to work on a custom preset, I got warning messages about stored errors that all reported over-voltage. I sent that on to FMA.

After reading on here, instead of creating a custom fuel table, I'm going to make a preset using manual charging. I am going to use the "generic high power" as my base to work from and copy that to a preset.

My questions are:
1) The best way to limit the voltage of the cells to indicate a charged state to the charger? Since there appears to be over-voltage charging on the packs I want to alter the "full charge" voltage to lower than 4.199.

My thought for the answer is to "check" the "Advanced Properties" for my new preset (my copy of "high power") go to the "fuel tab" and alter "fuel table 100%" from 4.199V to something lower like 4.15V (or possibly lower and creep up on a higher value later). Does this seem like a correct solution?

Another answer may be for me to change the "C/?" Termination setting on the "Termination Tab"?

2) When setting the manual charge current, am I setting it per pack since it asks if I'm parallel charging and how many packs OR should I be doing the math (2.2 Amps * #of packs)?

My thought here is to use the "per pack current" (i.e. 2.2 Amps in this case) and then tell it how many packs I'm charging. (this assumes that if I'm charging let's say 3 packs in parallel then by specifying a current of 2.2A and 3 for number of packs it will charge at or near 6.6A).

Thanks in advance,

Mike
Hi:

If you have been using a different charger to charge these LiPo's before you got the PL8, then chances are the over-voltage safety codes you received are due to the fact that the other charger over-charged the cells slightly. The PL8 is factory calibrated to be accurate to within 10mV. Just saying, that's one possibility.

Reducing the full charge voltage on the fuel table will not prevent the safety code you have seen. This safety code is based on the actual per-cell voltage measurement and does not have anything to do with the fuel table value.

C/? termination would also not be a way to fix an over-voltage error.

My guess is if you simply use the presets of the PL8 as is, and perform a few cycles with PL8 only, you won't get the over-voltage error messages any more.

But if you are still looking for a solution to prevent an over-voltage error, the parameter you would want to adjust is the "Charge Voltage" parameter on the Charge tab. Set it to something lower than 4.20V default.

Yes, if charging 3 packs in parallel and you want 2.2A per pack, the current should be set to 6.6A total.

Tim Marks
Tim Marks is offline Find More Posts by Tim Marks
Reply With Quote
Old Aug 31, 2010, 02:55 AM
Registered User
SteveM732's Avatar
United States, OR, Beaverton
Joined Feb 2008
1,976 Posts
Quote:
Originally Posted by drsmith751 View Post
Steve - Can you recommend the specs for a capacitor that will do the job.
Without knowing the magnitude of the voltage ripple, not really. What you want to do is use a large electrolytic capacitor to dampen the voltage just like the lead acid battery did. I have a couple 15,000uF caps handy that I would try if it were me, but I'd also dig around and find something in the 1,000-2,200uF range to see if that was enough. Also, make sure they are rated for about twice the highest voltage you expect them to see.

I have a pair of Mean Well 600W 15V power supplies that I have run flat out on the PL8 with no trouble whatsoever. I know nothing of the Iota supplies, but it looks to me like they may be fudging their datasheet numbers a bit as they claim to have 3 times less ripple and noise than my Mean Well. Unless of course it is due to the Mean Well SE-600-15 having 3 times better load regulation than the Iota DLS-55.
SteveM732 is offline Find More Posts by SteveM732
Reply With Quote
Old Aug 31, 2010, 06:47 AM
Registered User
United States, WI, Milwaukee
Joined Sep 2008
777 Posts
Quote:
Originally Posted by Tim Marks View Post
Hi:

If you have been using a different charger to charge these LiPo's before you got the PL8, then chances are the over-voltage safety codes you received are due to the fact that the other charger over-charged the cells slightly. The PL8 is factory calibrated to be accurate to within 10mV. Just saying, that's one possibility.

My guess is if you simply use the presets of the PL8 as is, and perform a few cycles with PL8 only, you won't get the over-voltage error messages any more.

Yes, if charging 3 packs in parallel and you want 2.2A per pack, the current should be set to 6.6A total.

Tim Marks
Thanks Tim, I'll try doing the a few cycles on the battery and go from there.

Would you recommend discharge down to 3.30v per cell during cycling?
Brownie433 is offline Find More Posts by Brownie433
Reply With Quote
Old Aug 31, 2010, 07:23 AM
Mis-guided heli guy
Jeff_edge540's Avatar
Austin, TX USA
Joined Mar 2007
1,470 Posts
Quote:
Originally Posted by everydayflyer View Post
You are talking about pulling approx. a 7 amp. load on a battery rated at 7Ah .and I bet that 7Ah rating is based on a 20 hour discharge rate. Chances are at 1C discharge rate it is less than 2Ah and for decent cycle life should never dischaged more than around 2 Ah. if that. Your 24.7 V power supply will not evev charge the Pb over approx. 40% state of charge so you really have perhaps 3Ah at best and you are starting off with them below the level they should ever be discharged to.

Specs.. on a 12V 7Ah I happen to have here.
Charge to
Standby use 13.5 to 13.8
Cyclic (what you are proposing) 14.0 to 15.0 volts initial current 2.1A max.

Chart here: Colored about 3/4 down

http://www.windsun.com/Batteries/Battery_FAQ.htm

12.3volts indicates approx. 70% charged

Charles
Gotcha. Thanks for the info and thanks for the link to the FAQ. Lots of useful info there.
Jeff_edge540 is offline Find More Posts by Jeff_edge540
Reply With Quote
Old Aug 31, 2010, 08:55 AM
President, FMA, Inc.
Tim Marks's Avatar
Joined Mar 2008
1,051 Posts
Quote:
Originally Posted by Brownie433 View Post
Thanks Tim, I'll try doing the a few cycles on the battery and go from there.

Would you recommend discharge down to 3.30v per cell during cycling?
Hi:

End of discharge voltage is dependent on the cells and everybody has his or her own opinion about it. I won't make any recommendation other than to say that 3.30v is likely safe for any LiPo. Some may take issue with that.

Tim Marks
Tim Marks is offline Find More Posts by Tim Marks
Reply With Quote
Old Aug 31, 2010, 11:42 AM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,634 Posts
Quote:
If you have been using a different charger to charge these LiPo's before you got the PL8, then chances are the over-voltage safety codes you received are due to the fact that the other charger over-charged the cells slightly.
Agree but the only time I have ever seen this happen is after charging on another charger and then doing a topping off(?) charge on the CellPro 10 or POWERLAB8. IMO it should not require any cycling to correct this jus a discharge as in using it or just discharging to Storage with the PL8. Next charge should be fine.

Charles
everydayflyer is offline Find More Posts by everydayflyer
Reply With Quote
Old Aug 31, 2010, 12:01 PM
President, FMA, Inc.
Tim Marks's Avatar
Joined Mar 2008
1,051 Posts
Quote:
Originally Posted by everydayflyer View Post
Agree but the only time I have ever seen this happen is after charging on another charger and then doing a topping off(?) charge on the CellPro 10 or POWERLAB8. IMO it should not require any cycling to correct this jus a discharge as in using it or just discharging to Storage with the PL8. Next charge should be fine.

Charles
Hi Charles:

True!

Tim Marks
Tim Marks is offline Find More Posts by Tim Marks
Reply With Quote
Old Aug 31, 2010, 02:14 PM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,634 Posts
OK I tried my PL8 on my Iota DLS45 and same issues as others. I could only manage a 10A charge on a 6S 6600 (really 4ea. 3S 3300s).

Used two of my IBM 235s 24V / 30A power supplies and no problem charging at 20amps.(see first attachment) however there were some amp. swings at start of charge and fans pulsed on and off.

Added two attachments with one IBM 235 ps being used..

Lesson learned today. PL8 works better with server power supplies than with Iota power supplies.

Charles
everydayflyer is offline Find More Posts by everydayflyer
Last edited by everydayflyer; Aug 31, 2010 at 03:00 PM.
Reply With Quote
Old Aug 31, 2010, 03:57 PM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,634 Posts
PL8 two hp ESP114 ps 6S @ 30A

Two hp ESP server power supplies in series 24V / 55A .

PL 8 chargeing 4ea. 3S 3300 as a 6S 6600.

Charles
everydayflyer is offline Find More Posts by everydayflyer
Reply With Quote
Old Aug 31, 2010, 04:21 PM
Registered User
gww528's Avatar
United States, FL, Jacksonville
Joined Mar 2008
818 Posts
Quote:
Originally Posted by everydayflyer View Post
OK I tried my PL8 on my Iota DLS45 and same issues as others. I could only manage a 10A charge on a 6S 6600 (really 4ea. 3S 3300s).

Used two of my IBM 235s 24V / 30A power supplies and no problem charging at 20amps.(see first attachment) however there were some amp. swings at start of charge and fans pulsed on and off.

Added two attachments with one IBM 235 ps being used..

Lesson learned today. PL8 works better with server power supplies than with Iota power supplies.

Charles
FYI, I am running two Iota DLS-55's in series and there is no problems whatsoever.
gww528 is offline Find More Posts by gww528
Reply With Quote
Old Aug 31, 2010, 07:51 PM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,634 Posts
What is the highest LiPoly cell count you have charged at 30 amps.?

The last attachment above was 24V at 30A into the 6S or 720 watts PL8 output but that was with 24V / 55 A available from a pair of hp serever power supplies.

Charles
everydayflyer is offline Find More Posts by everydayflyer
Reply With Quote
Old Aug 31, 2010, 07:54 PM
Registered User
SteveM732's Avatar
United States, OR, Beaverton
Joined Feb 2008
1,976 Posts
Quote:
Originally Posted by gww528 View Post
FYI, I am running two Iota DLS-55's in series and there is no problems whatsoever.
What is the highest current draw from the DLS-55's have you had without experiencing any problems?
SteveM732 is offline Find More Posts by SteveM732
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Sneak Peek! 2, 1:8 scale scratchbuilts ooby Scale Boats 31 Jul 24, 2011 08:30 AM
Discussion Proposed schemes for 2010 season RAF BAe Hawk display-sneak peek! Matt Halton Electric Ducted Fan Jet Talk 3 Dec 20, 2009 03:11 AM
Discussion Sneak Peek at the New Creation Museum Miami Mike Life, The Universe, and Politics 38 May 30, 2007 05:01 PM
Hey Mr. Lin, how about a sneak peek at the Hellcat? splatman GWS (Grand Wing Servo) 1 Jul 05, 2003 04:43 AM