On Saturday, November 28, 2015 at 9:52:42 AM UTC-8, Soartech wrote:
On Tuesday, November 24, 2015 at 12:15:55 PM UTC-5, Richard wrote:
On Tuesday, November 24, 2015 at 8:38:46 AM UTC-8, Jonathan St. Cloud wrote:
Any idea if I had a solar panel for charging would I need some sort of controller to charge these LifePO4 batteries?

If your old "Sealed Lead Acid" (SLA) needs replacing, here is an opportunity to get a 12 Volt 9 Amp hour LiFePO4 battery. I have been using these for several years and would never go back to SLA's.

Lots of RAS threads on LiFePO4 if you need more convincing.

These are a direct drop in replacement to your old 12V 7A battery but weigh only 2.6 pounds. Here's the link.

http://bioennodepot.com/bioenno-powe...lf-1209ws.html

Craggy Aero also offers the same discount.

http://www.craggyaero.com/lifepo_battery.htm

Richard
www.craggyaero.com

Jonathan,

Yes it is absolutely necessary to have a controller specific to the LiFePO4 batteries. If you charge at the higher voltage that solar panel outputs you will fry the battery.

Richard
www.craggyaero.com

You will not "fry" the battery because the battery has protection circuitry built-in.
From the specs:
"Includes built-in PCM (protection circuit module) which provides balancing of internal cells, and protection from overcurrent, undervoltage (overdischarge), and overvoltage."

If the voltage is too high it will simply prevent it from charging. All that is required is a simple regulator like an LM317 to keep the voltage from the solar cell at ~15 Volts. Most solar cells rated for 12V will put out around 18 Volts in strong sunlight.

Soartech,

I agree on the protective circuit BUT it will not protect higher voltages for extend periods of time.

I had a LiFePO4 vendor send me the wrong charger 24 volts instead of 12v.. Fried 3 LiFePO4 batteries. They got big and leaked. You would not want this happening in your nice glider with solar panels. Solar panels can deliver 22 to 24 volts. Please use chargers that also have the protective circuits and around 12 to 14 volts. That is what is recommended by the manufactures of the LiFePO4 batteries.

Richard
www.craggyaero.com