Originally Posted by SteveM732

" 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!!

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

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

Originally Posted by Brownie433

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

Originally Posted by drsmith751

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.

Originally Posted by Tim Marks

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?

Originally Posted by everydayflyer

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.

Originally Posted by Brownie433

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

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

Originally Posted by everydayflyer

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

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

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

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

Charles

Originally Posted by everydayflyer

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.

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

Originally Posted by gww528

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?