Quick Update: 11/4/2009 12:53 PM
So... we all know by now that I am impatient (even though I like to be methodical to a fault) so I couldn't resist just a test.
I decided to wire up 3 of my 5S 5AH 20/30C Turnigy LiPos in Parallel, Use one of Gary's balance parallel reducers (new name?) and finally connected the temperature sensor and the balance plug to iCharger to monitor cell voltages and pack temps during blind charge.
Power supply A is being used for the test, set to 20.7 HVC and effectively charging the presumed 14.6A rate into a 15AH 3P5S LiPo pack at just under 1C 14.6/3 = 4.8667 A per 5000 mah pack.
Charge process is completed now... SUCCESS !!!
Here are the specifics:
Pack Configuration: 15S1P 5000mah Turnigy Lipo - 20/30C
Pack Max Voltage: 62.25v (4.15v per cell)
Pack Min Voltage: 48v (3.2v per cell)
Pack Discharge Number: 7
Discharge Method: eBike Use
Discharge Max Current: 35 A
Discharge Amp Hours: 5122 mah
End of Discharge Pack Voltage: 52.524 v (or 17.508v per 5s segment +- .05v)
Average Cell Voltage at Rest: 3.5016v
Pack Configuration: 3P5S 15000 mah Turnigy Lipo 20/30C
Charge Max Voltage: 20.7 (should be 20.8 for 4.15v per cell but figured be safe than sorry)
Charge Current: Unknown - Educated Guess = 16.8269 A @ 20.8V Maximum
Monitor Method: Manual - iCharger1010B+ via LogView
Pack Resting Voltage: 17.508 v (remember converted 15S1P to 3P5S)
Resting Cell Voltage Range: 3.450 v - 3.559 v (already out of balance)
Voltage Maximum: 21 v @ 4.20v per cell x 5S
Voltage Minimum: 15 v @ 3.00v per cell x 5S
SOC 1% Voltage: .06v (because 6v swing from full to empty)
Beginning SOC - 17.508 - 15 = 2.508 / .06 = 41.8 %
SOC @ 15:00 - 19.247v : 19.247 - 15 = 4.247 / .06 = 70.7833 %
SOC @ 30:00 - 19.889v : 19.889 - 15 = 4.889 / .06 = 81.4833 %
SOC @ 45:00 - 20.672v : 20.672 - 15 = 5.672 / .06 = 94.5333 % almost done
SOC @ 46:20 - 20.700v : 20.700 - 15 = 5.7 / .06 = 95.0 % (this is where the supply was set to max out.)
SOC @ 50:10 - 20.751v : 20.751 - 15 = 5.751 / .06 = 95.85 % (our first cell just hit 4.159v)
At the end of chargeÃ¢â‚¬Â¦.
Cell Voltage Range: 4.149v to 4.159v
I ran my test a bit longer to ensure no damage or temperature rises happenedÃ¢â‚¬Â¦ actually I ran it about 30 minutes longer than I needed toÃ¢â‚¬Â¦ to 1:15 and more. Nothing heated up the cells actually balanced out a bit more in the end.
Next test will be logged using my new atmega based BMS PC Interface (thank god for 16x analog duplex multiplexers - monitor any cell, up to 16 with just 2 A2D pins and 3 digital IO pins (to control which cell you are sourcing analog input from) -
Some things I should mentionÃ¢â‚¬Â¦ I hope to soon determine if Nicks power supply is a knock off or off label mean wellÃ¢â‚¬Â¦
Knock Off = Lower Quality Imitation, ie Fake.
Off Label=Same Quality, Components and QC but branded to a different manufacturer for resale.
I am hoping that they are Off Label because I would love to determine how to control the output current of the supply. The thought of using FETs to switch at 63v and to dissipate 10A (the supply will be more than that) 630w of heat? NO WAY!!! With some luck his mod will be adaptable to MCU control.
Some good newsÃ¢â‚¬Â¦ there are 3 current sensing shunt resistors in the Meanwell (see the PCB pics with review) which means I can connect an appropriate voltage divider and then input the pre/post shunt voltage readings into the atmega I plan to use for control / management of this thing in the endÃ¢â‚¬Â¦ now I can calculate the current, since I know how to limit voltage by replacing the pot with a kind of digital pot controlled via atmega Ã¢â‚¬Â¦ it would be perfect to be able to manage the current produced by the power supply alsoÃ¢â‚¬Â¦ Then I could adapt to charge various chemistries and capacities (various AH) while managing the curve and use a FET just to disconnect the supply from the battery for an instant so I can sample the battery standing voltage before engaging the FET again to allow power to passÃ¢â‚¬Â¦ this would likely be checked each 3-10 seconds (configurable) to ensure battery within range and determine where we are in the charging cycle.
WellÃ¢â‚¬Â¦ the supply does what it's supposed to do and seemingly well. The outside got a bit warm but I expected that. Fan kicked on and ran for a while, until I opened the window (it's really cold here today).
All in all and assuming these units last for a considerable length of time (ie: the life of a well maintained pack, 2-3 years) and the type of abuse and use they will receive from meÃ¢â‚¬Â¦ I am very satisfied with the product and plan to purchase MANY MORE!
I am at this point pleased with sure-electronics also, and plan to place orders for several additional units of various size and capacity in the next days. I will be doing reviews on each of them also.
Complete full 15S2P charge test with manual monitoring of cells and temp, post results with video and pictures
Post schematic to provide analog 0-5v control of output voltage (interface to PC or MicroController)
Mod units to allow MCU programmable control of output voltage and monitoring of voltage and current
Get or find mod to control output current and post it with review
Adapt current control mod for MCU or PC control.
2010 Dahon Jack - GNG v1 - LYEN 6FET - 20/40A - 18S2P10AH - Nom:66.6v,1332w
2004 Hard Rock Pro Disc - Recumpence ms eDrive v4 - Astro 3220 4T - 12S2P16AH - HV110 - Left Side Drive - Gearing: 38mph
Nominal Peak Power @ 60 seconds: 5328 watts - Maximum Power: 49.8v, 120A, 5872w
2010 Downtube 8FH - Stock GNG v1 Stock Controller - EB809XC - 12-16S
2012 Downtube Nova 7spd - Stock GNG v2 - 12S2P10AH - EB809 - 12S-16S - 20A/30A,Nom VCC: 44.4, 888w