LiFePO4 direct driving XP-G - low voltage cutoff needed?

I'm thinking of driving some XP-Gs in parallel directly from a 3.2v LiFePO4 battery. Will I need a low voltage cutoff to prevent damaging the battery? If so, anybody know a source? Batteryspace only has 6.4v and higher.

Yes.

http://www.batteryspace.com/pcmprot...r1cells32vlifepo4batterypackat20alimited.aspx

Vermonter73 said:

I'm thinking of driving some XP-Gs in parallel directly from a 3.2v LiFePO4 battery. Will I need a low voltage cutoff to prevent damaging the battery? If so, anybody know a source? Batteryspace only has 6.4v and higher.

Click to expand...

No.

Not too sure if this fits the bill...
http://www.batteryspace.com/Balance-Module-for-3.2V-LiFePO4-Battery-Pack.aspx

So, do I need a cutoff or not?

You wont need low voltage cutoff, the led will stop passing measurable amounts of current and the led will not light before the lower allowable voltage of the cell is reached.

I use a 18650 lifepo4 to direct drive and xpg - gives a good 700ma to the led for the duration of the battery life :thumbsup:

Simple and foolproof

protein_man said:

You wont need low voltage cutoff, the led will stop passing measurable amounts of current and the led will not light before the lower allowable voltage of the cell is reached.

I use a 18650 lifepo4 to direct drive and xpg - gives a good 700ma to the led for the duration of the battery life :thumbsup:

Simple and foolproof

Click to expand...

This! You can think of the forward Vf as kind of a threshold. Yes the Vf will drop along with the battery voltage, but there will come a point at which the voltage won't light the LED, this could be under 3V, but you can safely discharge a LiFePO cell down to 2V without causing any reduction in capacity or doing any other damage.