First ride on lipo, awesome!! one question...

[Neo2172]

So I got my lipo order in from HK the other day and wired up a 5AH 12S pack, strapped it to the bike and went for a ride... I've gotta say that lipo is awesome! I get about the same range out of about 5 pounds of lipo vs 25 pounds of SLA! I have been charging them to 4.1v per cell, My question is at what cell voltage should I stop riding? On my ride today I stopped at 3.7v/cell. I was going from memory and I think this is what other forum members do... correct me if I'm wrong.

Also I have a Turnigy watt meter to monitor the voltage while I ride, I stopped using the battery when the under load voltage was 3.7v/cell, is this the correct method for knowing when to stop?

Cheers!

 

[spinningmagnets]

I try to not go below 3.65, but I haven't found an LV alarm I like yet. I may buy a cell-log8 when they are back in stock to try it out.

 

[AussieJester]

Use enough battery to not have to worry about lvc is the ticket Don't think i have got below 3.6v ever, before the pack was back on the charger

KiM

 

[liveforphysics]

You will be really happy for a long time if you always stop before 3.6 and charge to 4.1 or 4.15.

 

[neptronix]

Yup.. about 3.6v resting ( not while on throttle since you will get a little voltage sag )
Much below that is asking for trouble. And there isn't much in the way of power below that anyway. About 5% of your battery capacity.

If you have a celllog 8s, cell meter, or any other cell checking device, the effect in the above graph will make sense.

 

[Neo2172]

Yup.. about 3.6v resting ( not while on throttle since you will get a little voltage sag )
Much below that is asking for trouble. And there isn't much in the way of power below that anyway. About 5% of your battery capacity.

If you have a celllog 8s, cell meter, or any other cell checking device, the effect in the above graph will make sense.

So I should let all the way off the throttle, look down, and then get my reading? Would it be correct to say that my no load voltage should tell me when to stop, even if my under load voltage is significantly lower?

So lets say I'm riding along and my under load voltage is 3.4v/cell --- however with no throttle me resting voltage is 3.9v/cell --- Am I ok to keep riding a bit longer?

 

[biohazardman]

Well I guess that is one way of doing it. Another method might be to have the LVC on your controller or BMS set to stop you before you damage the batteries though makes things much easier if you set it up that way. I only use my BMS to balance charge my batts. Every controller I have purchased has shut things down reasonably close to LVC, when I was riding, so I have never had a battery damaged that way. I had to werq harder and be inventive to cause any damage. ;^)