Sunsaver MPPT & LiFePO4 Batterys

RWB

Hey I am wondering what the correct charge parameters would be with the Sunsaver MPPT 15A Soar Charge Controller if I were to use it to charge the following LiFePO4 Battery pack.

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2795

I know I can edit the Sunsaver MPPT charge controllers charging settings and was wondering if anybody knew what would be the best settings for this charger/battery combo.

Any help would be appreciated. I emailed Solar Guppy also.

Solar Guppy

Re: Sunsaver MPPT & LiFePO4 Batterys

That "battery" has its own control module

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=4879

So looks like you just feed it 13-15V and it does the rest ( battery pages suggests 13.33V )

dwh

Re: Sunsaver MPPT & LiFePO4 Batterys

Looking at that link in your post, the battery comes with a PCM which

"protects the battery from

# Overcharge (> 15.6 V)
# Over discharge (<8.0 V)"

It also says that the PCM does cell equalization.

That page also says " * Please use Smart Charger (10 A) for 12.8V LiFePO4 Battery Pack world-wide use to charge the pack with 4.8 hrs charging time "


And when you click the smart charger link that page says:

"#Rating output voltage: 13.8VDC with 3 stage charge mode

*
Stage 1: Charging current: 10.0A +/-0.5A
*
Stage 2: Charging voltage: 14.7V +/-0.3V
*
Stage 3: Floating voltage: 13.8V +/- 0.25V"

dwh

Re: Sunsaver MPPT & LiFePO4 Batterys

Solar Guppy wrote: »

( battery pages suggests 13.33V )

Actually, it says 13.33A, 40.00A Max.

Though, the 13.33A is probably a typo and should be 13.33v.

niel

Re: Sunsaver MPPT & LiFePO4 Batterys

now i'm not all that familiar with the li-ion requirements, but your own link leads to some of your answers. for example it should drop out of bulk at 14.7v and float voltage is to be 13.8v as stated for their charger. i would imagine that there would not be any eqing and i'm not sure of temp compensation as there wasn't a direct mention that i immediately saw. this is fairly pricey for that 40ah and unless you're getting a deal, i would not go this route.
edit to add- boy you guys are quick.;)

dwh

Re: Sunsaver MPPT & LiFePO4 Batterys

niel wrote: »

i would imagine that there would not be any eqing

edit to add- boy you guys are quick.;)

According to the page for the PCM unit:

"it provides equilibrium function during charging, e.g. PCM will detect each cell's voltage and trim higher voltage until other cell's voltage reach same" i]sic[/i

CraigC

Re: Sunsaver MPPT & LiFePO4 Batterys

After a little research I decided to use a modified version of what the author of the blog http://solarbodge.blogspot.com/ was using. He has a 24V system and I have a 12V. Here's the settings I'm using to charge my StarkPower SP-12V100-EP 12V 100Ah LiFePO4 (http://store.starkpower.com/12V-100AhStarkPower-UltraEnergy-Lithium-Ion-Battery-LiFePO-Energy-Storage-Battery_p_24.html with my Panasonic HIT POWER 225A;

Absorption Target Voltage: 14.00 (3.50)
Absorption (Constant Voltage) Cumulative Time : 10 mins
Absorption Time Extended: none
Float Target Voltage: 13.4 (3.35)
Float Exit Time: 720 minutes
HVD (trigger): 14.50 (3.625)
HVD (release): 13.20 (3.30)
Max Regulation Voltage: 14.20 (3.55)
Temperature Compensation: Pack -30mV/C (25C to 80C)

Anyone have any recommendation or improvements?

Thanks,

Craig

BB.

Re: Sunsaver MPPT & LiFePO4 Batterys

Make sure of the "correct units" for:

Temperature Compensation: Pack -30mV/C (25C to 80C)

It may be -5 mV per degree C per Cell (12 volt -> 6 cells for a 12 volt lead acid battery or -30mV per degree C). I am not sure which unit (value) is use for programming the controller.

-Bill

CraigC

Re: Sunsaver MPPT & LiFePO4 Batterys

CraigC wrote: »

After a little research I decided to use a modified version of what the author of the blog http://solarbodge.blogspot.com/ was using. He has a 24V system and I have a 12V. Here's the settings I'm using to charge my StarkPower SP-12V100-EP 12V 100Ah LiFePO4 (http://store.starkpower.com/12V-100AhStarkPower-UltraEnergy-Lithium-Ion-Battery-LiFePO-Energy-Storage-Battery_p_24.html with my Panasonic HIT POWER 225A;

Absorption Target Voltage: 14.00 (3.50)
Absorption (Constant Voltage) Cumulative Time : 10 mins
Absorption Time Extended: none
Float Target Voltage: 13.4 (3.35)
Float Exit Time: 720 minutes
HVD (trigger): 14.50 (3.625)
HVD (release): 13.20 (3.30)
Max Regulation Voltage: 14.20 (3.55)
Temperature Compensation: Pack -30mV/C (25C to 80C)

Anyone have any recommendation or improvements?

Thanks,

Craig

The way I have the float exit time set I'll only reach 14V once each morning and then continuously charge at 13.4v so my typical day would go as follows;

- night - battery continues to drain using about 10-12Amps running my fridge/freezer
- before controller wakes up in the morning battery is 12.5V
- Bulk/MPPT starts and runs 1-2 hours charging to 14V. Freezer kicks in a few times while charging.
- Absorption starts and keeps voltage at 14V for 1o minutes.
- Float begins and when battery voltage drops below 13.4V float starts charging maintaining a constant voltage of 13.4V until it gets dark.
- night begins and voltage drops from 13.4V to 12.5V over the next 8-10 hours running my ridge/freezer
- day over

Would it be better if the float exited sooner (after 2-3 hours) so the bulk/mppt stage would occur a couple times a day?