lithium l batteries?
 

have just inherited a couple of sony f950 batteries. my client never used them and had them in a cupboard for about 18 months (or longer). he couldn't remember whther they were stored charged or not, so i put them on my sony charger (v700), which informed me they were fully charged...

put one on the camera today and it read something like 350mins, within 10mins it was flat.

anyone have any experience with long term storage of lithium L batteries, and what i might be experiencing?

i have put it back on the charger and will see what happens, but in the meantime, just wondering whether i'm wasting my time,

tia

leslie

I would try charging them up again and letting them run down all the way, then charge them up one more time. If they still last only 10 mins. after that then I would say they are shot.

One of the chargers I just bought had an interesting note in the instructions.
It said not to store Li Ion batteries discharged for a long period of time. That if you put a battery on the charger and it shows full but then has little or no charge in the camera, the battery is bad.

I hope this is not the case with your batteries but it sounds like it may be.

well, just left one of them on my v700 charger overnight. shows 5hr 23mins (about what i'd expect), however, wont find out till next week when i have a few days shoot. i'll put it on first and see what happens (i do have some 'good' batteries anyway).

what's the best way to discharge lithium l's, other than in the camera?

leslie

Leslie,
Sorry I don't have an answer for the best way but I have a question.
I heard that it was best to store Lithium batteries fully charged (Such as the Sony cam batteries) and that the best way to store lead acid batteries (such as some battery belts) was discharged, with the resultant need to charge them back up just before you use them.
Can anyone comment on this?
I seem to remembre deep in the past making a discharger that consisted of a 12 v light bulb and wiring and clips that you attched to the battery and let run. It seems like you weren't supposed to let the light go compltely out (total discharge) just dim considerably. I can't remember. My mind is almost totally discharged I think.

NO. Do not store lead-acid (aka starved electrolyte) batteries discharged. The lead turns to a physically weak lead sulphate when discharged and can easily be damaged. For sealed lead gel batteries, charge slowly to prevent bubbles from forming in the acid gel.

I'm no authority on lithium batteries, but I read a blog from a guy that sells batteries (sorry, forgot the link) and he indicated that lithium should be stored in neither a fully charged or discharged state. I would follow the manufacturers recommendations.

My friend recently did a literature survey for a technical university about how to prolong the usable life of lithium-ion batteries. I enclose his summary. The emphasis is on laptops but most of it holds for cameras as well. Nothing new but quite well nut-shelled.

1. Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly caused by heat rather than charge / discharge patterns.

2. Batteries with a fuel gauge (laptops) should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely.

3. Keep the lithium-ion battery cool. Avoid a hot car. For prolonged storage, keep the battery at a 40% charge level.

4. Consider removing the battery from a laptop when running on fixed power. (Some laptop manufacturers are concerned about dust and moisture accumulating inside the battery casing.)

5. Avoid purchasing spare lithium-ion batteries for later use. Observe manufacturing dates. Do not buy old stock, even if sold at clearance prices.

6. If you have a spare lithium-ion battery, use one to the fullest and keep the other cool by placing it in the refrigerator. Do not freeze the battery. For best results, store the battery at 40% state-of-charge.

From what I remember looking at on my Sony Batteries, they are the same as the li-po's I and others deal with in the hobby industry... Yes, they are different, bur as far as storage is concerned, the rules are the same. You always want to store them charged (not fully but I cannot remember the percentage). And when cycling you don't really want them to "rapidly" discharge them below 30% of their capacity....

For a cycler, I am sure you could rig one up from a cross between a hobby discharger/charger and an inexpensive sony charger. Basically you would need the hobby charger to cycle the batteries as this is built into chargers for the lithium batteries and the cheapo sony or other brand charger to make the "leads" with bananna plugs(this is the hookup for the vast majority of chargers that work with the Lipo's and higher ended batteries. The only thing that honestly I am not sure about as I only use LiPo is if they are compatable with Lithium Ion's.

Something in my mind tells me that I remember them being compatable for charging, but if your serious about creating some type of cycler you can contact Tower Hobbies or better yet, someplace like Heliproz as the guys/gals at Heliproz are nice, extremely knowlegeable and will talk to you for as long as they can and arent swamped... The lithium type of batteries are the newest craze in the hobby industry and there are tons of chargers and dischargers now on the market to play around with... I actually have two chargers. One digital and one analog. Either can charge Lithium and I use the cycler I have to charge 12volt car batteries on top of the batteries I use in my r/c equipment....

Another way to cycle the battery is simply to allow it to run down in your equipment and then charge it back up. Does certainly put wear and tear on your camera or whatever item you have it hooked to, but this is an easy way...

But they probably just need to be cycled a few times depending on how long they have been in the discharged state. You may be able to recover them by cycling....

Damon, Jyrki Hokkanen summarized Li-Ion care exactly right. In addition, only high end Li-Ion batteries have fuel gauge circuits built-in. The only reason ever to cycle a Li-Ion battery is to recalibrate that circuit. Cycling does not help in bringing an old or defective Li-Ion battery back to life. If a Li-Ion battery does not hold charge, there is no magic fix. :-(

i posted (or thought i did) a reply a couple of days ago....

well, both batteries seemed to have revived. both showing around 360mins life, and so far discharging in camera at a normal rate...

a. picked up a sony light that uses lit l batteries. don't have that much use for it, but found it gave a reasonable 'fill', with a bit of frost over it, when used on interviews.

b. interesting to note 'shelf' life. dont remember ever seeing a use by date on a battery? i would presume a lot of batteries must be floating around that still aren't bought after a year or so?

c. have been using lit l (sony originals) for the last 8 years or so - incl two original 750's which, (against all recommendations here at least), i have shot with till the camera cuts out, then fully recharged. they're still going strong...

anyway, many thanks to you all, i appreciate all the input and advice,

leslie

I have Info-Lithium batteries that I bought back when when I got my VX-1000 and that was a long time ago. I have used the same batteries on my VX-2100 and now on my V1U. While they don't have 100% of the capacity that they had when new, they still work well. I wish my Anton-Bauer batteries were as trouble free as the Sony's. I never gave my Sony batteries a lot of special care. Usually they get charged and then sit in the camera bag until needed. BTW it is Ni-Cad batteries that should be stored in a discharged state.