Can I top off 14500's?

SO, Im curious. I have been playing with my new toys lately and have a question about charging. I have the nitecore i4 V3 charger, and use eagletac 18650 3400mah, and Zebralight ZL14500's on it. Now, so far I have not been using the batteries all the way down at all. In fact, after using them a decent bit at nights mostly, it seems the batteries are still very charged. I mean, i usually top them off until solid led lights on the charger before I leave the house for the night. But is this bad if lets say, the batteries were still almost a full charge? With my SC52, i use the thing all the time and it just never seems to drain the batteries. Should I wait until the "volt meter 4 clicky thing" reads less than full?

I don't know if Im explaining this right. When i use the 4 click thing to tell me how low the battery is, its almost always 4 blinks, or full. But, to be safe I like to get a full charge before I go out in case I use the light more than usual. Is this ok?

Or, can I hurt the batteries by topping them off instead of waiting until they're dead before charging them again?

Thanks for any help in advance. I love my new lights so much. I am so happy I found this forum.

dave

Sorry guys to make another thread about this, but my last post was moved to the 18650 thread, and I would like to know if its okay to top off my zebra light 14500 840mah batteries, like EVERY DAY. Does this hurt the battery? I know its okay to top off a lot, but every day charging I would think is something else.

Thanks again, for all the help. And, sorry again for posting again about this, I just want to be safe.

dave

Keeping average voltage high will reduce service life. If I was going to top off every day after a shallow discharge, I would use a lower charge voltage like 4.1 to minimize the stress on the cell.

Typically, what voltage are you reading at the end of an average day of use, on your 14500s? Maybe you can go two, or threee days between charging? I try and recharge when I'm below 3.9v, even going down to 3.6-3.7v.

If you're running them down through the course of a single day, charge them up nightly, but expect to go through that cell in probably a year's time.

Chris

Trying still to locate my voltmeter. I know its around somewhere. I think I'll report back when I found it I suppose. As of now, no voltmeter, just using the 4 click "test" on the sc52, and usually blinks 4 times meaning battery still at top charge.

Lithium-ion batteries like the 14500 can be damaged if they drop below 2.7V and EXPLODE the next time you try to charge it.
Always top them off after use, NEVER let them run down.

LEDninja said:

Always top them off after use, NEVER let them run down.

Click to expand...

That's a bit of a sweeping statement. It takes me several days of normal use to get the cells in my TM11 down to around 3.7V. If you simply check regularly and make sure your cells don't ever drop below say 3.2V-3.5-V, you should be fine.
With that said, topping off regularly is totally okay too, your cells might just not last as many years that way.

LEDninja said:

Lithium-ion batteries like the 14500 can be damaged if they drop below 2.7V and EXPLODE the next time you try to charge it.
Always top them off after use, NEVER let them run down.

Click to expand...

No expert here, but I think that there's a 'time component' that your equation is missing. If you do discharge them down, like HKJ does, to 2.8v-ish, you'd probably want to charge them back up right away to prevent those copper molecules from migrating and creating shunts/shorts.

I actually ran a Sanyo 840 down to 2.78v (upon 3 min. rebound) the other day and charged it right back up with little worry.

If I had left it alone for a month, I might be sweating things a bit.

Chris

Thanks for the replies, but now I have another question. What you guys are saying about time, does this mean you can't leave these batteries without being used for an extended period of time or they can blow up? I have protected cells, but don't know if this matters here. If I, lets say, didn't use the lights for a month or two, i need to make sure they are fully charged first? Can you elaborate on this time issue with Li-ions that you are speaking of? Thank you
dave

LEDninja said:

Lithium-ion batteries can be damaged if they drop below 2.7V and EXPLODE

Click to expand...

2.7V is arbitrary in 2 ways.

1. Check the datasheet for the particular cell (note: not the marketing blurb from the company that rewrapped the cell i.e. AW, Xtar, Eagletac, Keeppower, etc. if it's a rewrap, but the actual datasheet from the cell manufacturer, i.e. Sanyo, Panasonic, LG, Samsung, Sony, etc.) The datasheet will always specify what the cutoff voltage is. In many cases it is not 2.7V - popular cells vary from 2.5 to 3.0V cutoff.

2. Cutoff voltage is under load. In general, important voltages for Li-ions are specified while current is flowing and are not resting voltages, both charge and cutoff. If a cell was discharged until the resting voltage was near cutoff and the load was not very light, the voltage could have been much lower under load, potentially causing damage.

d.weglarz13 said:

Thanks for the replies, but now I have another question. What you guys are saying about time, does this mean you can't leave these batteries without being used for an extended period of time or they can blow up? I have protected cells, but don't know if this matters here. If I, lets say, didn't use the lights for a month or two, i need to make sure they are fully charged first? Can you elaborate on this time issue with Li-ions that you are speaking of? Thank you
dave

Click to expand...

Li-ions cells self-discharge very little, but certain flashlights (especially those with electronic switches and voltage displays) do tend to run them down over time. Make sure you always fully lock-out your lights.

Ok, I will do that. Is it better to just keep the batteries out of the light when resting for an extended period of time? Thanks

d.weglarz13 said:

Ok, I will do that. Is it better to just keep the batteries out of the light when resting for an extended period of time? Thanks

Click to expand...

Just lock out the tail caps. Twist the cap off until the light doesn't turn on, if it's off, or turns off, if it's on.

Parasitic drain is the term. Some lights have it slightly, some have it in spades and some don't have it at all, but just lock out your tail cap and you can still keep the battery in place.

That's how I do it anyhow.

Chris

Thanks again for all the help!