Thoughts on battery storage and charging

[Signal 20]

I have recently been very busy with work and a new addition to the family, and with that occuring I have to say my cave diving has taken a backseat for a short time. So I was wondering what most of you do when you know you wont be using your Primary light and DPV for months at a time. I currently have them connected to the chargers and was thinking about leaving them on the chargers while they lay unused.

What do most of you do when your not gonna be using your lights and dpv for awhile. Does anyone have any thoughts on damage that would occur from being left on the charger for an extended perior or would it be better to not charge it and hope the battery stays good?

[hfig]

I'm not a expert by any means, but from how I understand it, the question you are asking really depends on what kind of battery you are using. ie. NiMH, L-ion, etc...

[ssmdive]

NiCad, NiMah, and lead acid are best stored with a full charge. But they will drop a little from just sitting there. They should be cycled about once a mth to keep from developing a memory.

Lipos are best left at a 50% charged state. They also will drop a bit, but at a MUCH lower rate. Lipos can be left at around 50% for a long time. Then just charge them up MAYBE cycle them once and they should be fine.

Neither battery should be left on a charger for a long period of time unless you have a charger that can read the battery and make adjustments. A constant rate charger left on a Nicad, Nimah, or lead acid can fry them... Lipos can explode.

[Jim Wyatt]

NiCad, NiMah, and lead acid are best stored with a full charge. But they will drop a little from just sitting there. They should be cycled about once a mth to keep from developing a memory.

Lipos are best left at a 50% charged state. They also will drop a bit, but at a MUCH lower rate. Lipos can be left at around 50% for a long time. Then just charge them up MAYBE cycle them once and they should be fine.

Neither battery should be left on a charger for a long period of time unless you have a charger that can read the battery and make adjustments. A constant rate charger left on a Nicad, Nimah, or lead acid can fry them... Lipos can explode.

This is what I have always understood as well. I was told by Light Monkey dudes that the Li-ions should be stored long term at 35% charge.

[ssmdive]

The exact % is up for debate.... 30-50% is the range. I use 50% because it is easier, and I am lazy.

But if the company tells you X%, X is what I would use.

Some more info:

http://www.slkelectronics.com/lipodapter/storage.htm

And see the attached sheet that has some really good info. Basically, charge state and temperature are the major factors that can hurt a lipo.

[Puttzer]

I have recently been very busy with work and a new addition to the family, and with that occuring I have to say my cave diving has taken a backseat for a short time. So I was wondering what most of you do when you know you wont be using your Primary light and DPV for months at a time. I currently have them connected to the chargers and was thinking about leaving them on the chargers while they lay unused.

What do most of you do when your not gonna be using your lights and dpv for awhile. Does anyone have any thoughts on damage that would occur from being left on the charger for an extended perior or would it be better to not charge it and hope the battery stays good?

I just charge my battery for a day to full charge after my last dive and forget about it. I charge again the day before my next dive.

My dives are frequently months apart but some times ...... weeks.

[LCF]

We have a lot of NiMH batteries that don't get used regularly. We put them on the charger the first of the month, overnight, and take them off. It seems to have worked so far.

Our LiIon batteries get used often enough that it hasn't been an issue.

[FW]

I have recently been very busy with work and a new addition to the family, and with that occuring I have to say my cave diving has taken a backseat for a short time. So I was wondering what most of you do when you know you wont be using your Primary light and DPV for months at a time. I currently have them connected to the chargers and was thinking about leaving them on the chargers while they lay unused.

What do most of you do when your not gonna be using your lights and dpv for awhile. Does anyone have any thoughts on damage that would occur from being left on the charger for an extended perior or would it be better to not charge it and hope the battery stays good?

I am pretty sure that none of the current batteries are supposed to stay on the charger all the time.

A once-a-month-overnight charge works fine for NiMH, NiCad, and SLA. I don't have any Li batteries, so I won't speak about them.

[scububa]

When my lights sit without diving, I also put on the charger once per month. I remove when the charger indicates it is happy.
One charger is solid to charge and blinky when happy.
The other is the opposite.

This is why I could never have two girlfriends (wife/mistress, etc.)
Too confusing

BTW, one of the battery packs (DR 10W HID converted to LED a year ago) I bought used (over a year old) and have had since OCT 05. I haven't done a burn test in a while, but I regularly get 2.5 hrs plus with the LED upgrade.

[saturation]

To maximize life, SLA type batteries should be stored fully charged. It should be topped up every 3-6 months, depending on the self discharge of your particular model. Leaving the battery discharged will cause sulfation and shorten the life of the battery quite a bit.

http://en.wikipedia.org/wiki/Sulfation

The Genesis batteries self discharges very little. I need not top it up for at least 6 months, the longest its sat unused, and it still registers a full charge.

http://en.wikipedia.org/wiki/Lead-acid_battery

NiMH can be left uncharged, charge and discharge cycles reduce its overall life especially if you fast charge them. It self discharges quite noticeably, at least 1% a day if not more, so 'topping' up a battery pack and then not using it really reduces its overall life since it will self discharge while it sits unused.

To reduce self discharge, put it in a refrigerator, or keep it cold but do not freeze them.

http://en.wikipedia.org/wiki/Nickel_...ry#Discharging

In 10 years, I've used up 2 NiMH packs for an HID light, and in excess of 600 dives on them. I discard them when the burn time is 2.5 hours, because that's my typically dive time. A new pack burns for at least 4 hours using HID. For LED, I hope it will last longer.

I have no personal experience with Li batteries, but Wikipedia can help:

http://en.wikipedia.org/wiki/Lithium...attery#Storage