Solar charging LiFePO4

oil pan 4

Has any one tried putting together a small 4 cell stack (13.2v) solar power system?
What is a good OCV panel voltage to look for? For lead acid I know you want at least 17ocv and 18ocv is better.
Whats a good or an adjustable charge controller that is 4 cell LiFePO4 compatable? (cuts off some where around 14.8v)

mike95490

Re: Solar charging LiFePO4

There are no solar - LiFePO4 compatible chargers that I know of. You could look for one of the more sophisticated chargers that allow you to tweak the voltage settings, and come close.

oil pan 4

Re: Solar charging LiFePO4

Thanks,
That is what I was worried about after I searched around and didn't find any.

oil pan 4

Re: Solar charging LiFePO4

I sent off a few emails asking about solar controllers for LiFePO4 banks.
I will post results when I get them.

oil pan 4

Re: Solar charging LiFePO4

Morning star didn't have anything.

stephendv

Re: Solar charging LiFePO4

There's a guy on another forum who's using a morningstar controller to charge his 400Ah 24V LiFePO4 bank: http://www.navitron.org.uk/forum/index.php/topic,8368.msg187946.html#msg187946
His blog: http://solarbodge.blogspot.com/2012/02/more-settings-tinkering.html

oil pan 4

Re: Solar charging LiFePO4

stephendv wrote: »

There's a guy on another forum who's using a morningstar controller to charge his 400Ah 24V LiFePO4 bank: http://www.navitron.org.uk/forum/index.php/topic,8368.msg187946.html#msg187946
His blog: http://solarbodge.blogspot.com/2012/02/more-settings-tinkering.html

Thanks a lot for that.
Interesting he did what I have been considering, using a lead acid charger with a time delay that cuts off the whole system.

Siljaars

Re: Solar charging LiFePO4

mike95490 wrote: »

There are no solar - LiFePO4 compatible chargers that I know of. You could look for one of the more sophisticated chargers that allow you to tweak the voltage settings, and come close.

At genasun.com I know of gv-5, gv-10, and gv-boost exist.The efficiencies for these LiFePO4 MPPT charge controllers look great to me, but certainly not low cost.
http://genasun.com/products-store/mppt-solar-charge-controllers/mppt-for-lithium-batteries/

BB.

Re: Solar charging LiFePO4

We have had a few posts here about Genasun:

Google Search for Genasun on site:wind-sun.com forum

I am not sure anyone has used them yet here and posted a review.

-Bill

gww1

Re: Solar charging LiFePO4

http://forums.energymatters.com.au/solar-wind-gear/topic3936-60.html#p30990

http://www.outbackpower.com/forum/viewtopic.php?f=29&t=7087

Maby these post would fit here?
gww

CraigC

Re: Solar charging LiFePO4

Does anyone have recommended settings for the Sunsaver MPPT to charge the following battery?
Model No. SP-12V100-EP
Voltage: 12V
Capacity: 100Ah, 1280Wh
Chemistry: LiFePO Life Cycles: 2,000 @ 80% DOD
BMS YES (Internal)
Max Charge Voltage: 14.6V
Discharge Cut-off Voltage: 8.2V
Max Charge Current: 50A
Max Discharge Current: 100A
Max Starter Current: 300A
Operating Temperature: -22°F to +140°F, (-30°C to +60°C)


thanks!

mike95490

Re: Solar charging LiFePO4

Find what the BATTERY charging profile is, then look for a charger that matches it. Most solar chargers are designed only for lead acid chemistrys.

spacevoyager

Re: Solar charging LiFePO4

ECS has developted a solar charge controller for LiFePo4. The charge controller can work with a BMS System called LiPro1-1
See http://www.ecs-online.org/Charge-controller:::1.html?language=en

Regards
Tom

BB.

Re: Solar charging LiFePO4

Tom,

This link to the BMS (Battery Management module) is probably of most interest regarding Li chemistry folks:

http://www.ecs-online.org/BMS:::2.html?MODsid=262l8cjvp66t299crmuc0q07r0

It looks like you have software that you can put on a PC and communicate with the BMS units?

www.ecs-online.org/media/content/DATENBLATT_LiPro1-1_EN_REV0_3.pdf

Interesting.

-Bill

SandyP

Re: Solar charging LiFePO4

Another link to a BMS system for LiFePo:

http://www.ev-power.com.au/-EV-Powerpak-Custom-LFP-Batteries-.html

mtdoc

Re: Solar charging LiFePO4

Any solar cc that allows you to program a LiFePO4 compatible charging profile will work. I know that the Midnite Classic will work and I've read about people using Outback and Morningstar as well. Since solar ccs are generally designed for 12,24 or 48 volt battery banks, your LiFePO4 pack will need to have a nominal voltage near to that (as yours does).

As others have mentioned, you will need a BMS to ensure individual cell balancing.

papa

Re: Solar charging LiFePO4

Solar charging Li-ion?.... easy....

Just grab one of these: http://www.hobbyking.com/hobbyking/store/__6478__IMAX_B6_AC_Charger_Discharger_1_6_Cells_GENUINE_.html

... and feed it 11-18vdc from any source. This example accommodates from 1 to 6 cells. Many others to chose from so look around.

unicornio

Re: Solar charging LiFePO4

papa wrote: »

Solar charging Li-ion?.... easy....
Just grab one of these: http://www.hobbyking.com/hobbyking/store/__6478__IMAX_B6_AC_Charger_Discharger_1_6_Cells_GENUINE_.html
... and feed it 11-18vdc from any source. This example accommodates from 1 to 6 cells. Many others to chose from so look around.

i have one of this, it is a very good, very versatile and precise charger, but i use it for charge lipos for RC helicopter. but i thing we are speaking about other scale of batteries...;-)

papa

Re: Solar charging LiFePO4

After reading the battery's description this time, it appears that this model has an on-board BMS. They also claim that it's a "drop-in" FLA replacement that needs the typical 14.6v charge voltage. Reads to me that the OP can use nearly any CC that accommodates FLA.

At 900 bucks a pop, and blessed with only a 1 year warranty, I wouldn't even consider it.

http://store.starkpower.com/12V-100AhStarkPower-UltraEnergy-Lithium-Ion-Battery-LiFePO-Energy-Storage-Battery_p_24.html