New PowerCubes - Should I save them for special jobs?

[Robert Starling SOC]

My new rig came with two PowerCubes. The rest of my batteries are IDX E10's.

 

Rather than put the new PowerCubes into regular rotation with my other batteries and start the wear of cycling them, I was thinking it may be prudent to shelve them and only use them for special jobs where there are high amperage requirements. I think those jobs/cameras are going to be few and far between here in the Las Vegas market which seems to consist of F900 and Varicam work.... or until such time our Governer outlaws all the migrant Steadicam operators in LA from coming over here to shoot all the nice film jobs :rolleyes: or I begin to move myself up the food chain and get more experience.

 

What would you do... about the batteries that is.

 

Thanks!

[pauldudeck]

My new rig came with two PowerCubes. The rest of my batteries are IDX E10's.

 

Rather than put the new PowerCubes into regular rotation with my other batteries and start the wear of cycling them, I was thinking it may be prudent to shelve them and only use them for special jobs where there are high amperage requirements. I think those jobs/cameras are going to be few and far between here in the Las Vegas market which seems to consist of F900 and Varicam work.... or until such time our Governer outlaws all the migrant Steadicam operators in LA from coming over here to shoot all the nice film jobs :rolleyes: or I begin to move myself up the food chain and get more experience.

 

What would you do... about the batteries that is.

 

Thanks!

 

Robert,

 

The biggest issue with li ion batteries, no matter who manufacturers them, is the life span. Whether you use them or not, they will go bad. As with any re-chargeable battery, you should use them. The more they are used, the better off they are. One major drawback of li ion batteries is the fact that is has "irrecoverable self-discharge", which means if you leave it off of a charger, and it loses cacpacity, you can never get that lost capacity back again, unlike NiCad and NiMH which will charge up to 100% again.

 

Li ion typically has a self-discharge rate of approximately 1% per month. So, technically if you leave a battery sit on the shelf for one year, you will only be able to use 88% of the batteries capacity. The 12% that you lost is gone forever. This is true for ALL li ion batteries, which is why you get a shorter life span on the cells.

 

In my opinion, use the batteries to their potential!!

 

Regards,

Paul Dudeck

[WillArnot]

I find this kind of response extremely helpful, and notable in that Paul reps Anton Bauer. It is the kind of info that we ops need to know about, and I think it's great that Paul rises above the partisan politiking of competitive manufacturers to shed such light on battery technology.

 

Many thanks for your constructive input here Paul. This is the kind of attitude and knowledge that I seek to do business with. Good question Robert!

 

Will

[Alec Jarnagin SOC]

I started with Anton Bauer on my Model 2 then my 3a by modifying them because Anton Bauers could be found worldwide and were the best batteries around. As the competition has gotten much stiffer and other mounts (notably the V-Lock) have caught on, I still find myself sticking with Anton Bauer. In part because I still like the product but a lot of it has to do with Paul. He has always been there for me. Again, customer service wins clients.

 

Oh, and Robert, if you don't need the high draw batteries at this time, you may be able to get something great in trade for them around these parts.

[Erik Brul]

One major drawback of li ion batteries is the fact that is has "irrecoverable self-discharge", which means if you leave it off of a charger, and it loses cacpacity, you can never get that lost capacity back again, unlike NiCad and NiMH which will charge up to 100% again.

 

In my opinion, use the batteries to their potential!!

 

Regards,

Paul Dudeck

 

I thought it was the other way arround ! I Mean, the "irrecoverable self-discharge or memory effect ", i have seen this with my formely used Nicad and Nimh batteries. Mostly with the NP1 in the old days.

So i thought buying only Li ion batts will not have this kind of problems.., :(

 

Erik

[pauldudeck]

One major drawback of li ion batteries is the fact that is has "irrecoverable self-discharge", which means if you leave it off of a charger, and it loses cacpacity, you can never get that lost capacity back again, unlike NiCad and NiMH which will charge up to 100% again.

 

In my opinion, use the batteries to their potential!!

 

Regards,

Paul Dudeck

 

I thought it was the other way arround ! I Mean, the "irrecoverable self-discharge or memory effect ", i have seen this with my formely used Nicad and Nimh batteries. Mostly with the NP1 in the old days.

So i thought buying only Li ion batts will not have this kind of problems.., :(

 

Erik

 

Erik,

 

"Memory" was a term that was used a while ago. Many people have the wrong impression of what it really means. A battery cannot get "memory". It is impossible to do. In fact, what it really "refers" to was the very antiquated chargers that were used way by when. These chargers strictly used one type of charge "cut off" to determine when a battery was fully charged. This "minus delta v" cutoff is ok, but is not 100% accurate. As a matter of fact, there is no "one" perfect charge termination for any battery out there. Add the fact that the charger used a sole charge determination, with the fact that the cells in the battery were never balanced properly and most old chargers were "timers", so they would just charge a battery for a certain period of time. Well, that would be OK if the batteries were completely discharged every time you went to charge it. If the battery was half fulll, then you would overcharge the battery by up to 50%, thus causing alot of heat build up with the cells. What is the number one killer of batteries? Heat! Couple these phenomenons with a few more, and you get this so-called ?memory" effect.....

 

If you want to read more about stuff like this, Anton/Bauer publishes the Video Battery Handbook, which is free. Just send me an email at pdudeck@antonbauer.com and I will be happy to send anyone a copy. This talks in general about charging batteries, cell technologies, lighting and more....

 

Anyway, to get back on track, "self-discharge" is when you leave a battery sit off charge for a period of time. The longer it sits, the more it will self-discharge. A NiCad or NiMH will self-discharge at a rate of about 3% per day. But, this self-discharge is 100% recoverable. If you use Anton/Bauer batteries and chargers, you will notice the "Balancing" mode, or flashing green LED on the charger. One of the features of the Balancing mode is to compensate for self-discharge and ensure that all of the cells in the battery are fully charged. Going back to my original post, a li ion battery may only self-discharge at a rate of 1% per month, but once it self-discharges, it is gone forever.

 

Li ion has two main advantages over NiMH and NiCad: 1) weight and 2) a very low self-discharge rate.

 

I hope this helps.

 

Paul

[chris fawcett]

I hope this helps.

Thank you Paul, it does.

 

Best Regards,

 

Chris

[Brad Smith]

Thanks Paul, it's a real bonus of this forum that we can hear from the people and businesses that shape our industry...... Just one more question?! Is the net of all you've said that, If you've got Li Ion batts, the best way to store them when they're not being used, is on the charger to keep them topped up? Thus eliminating self discharge?

 

Best,

[pauldudeck]

Thanks Paul, it's a real bonus of this forum that we can hear from the people and businesses that shape our industry...... Just one more question?! Is the net of all you've said that, If you've got Li Ion batts, the best way to store them when they're not being used, is on the charger to keep them topped up? Thus eliminating self discharge?

 

Best,

 

Brad,

 

Yes, ideally, the best way is to keep them on the charger.

 

If you are leaving li ion batteries off of charge, then the best way to store them is to discharge them to approximately 40% of charge and let them sit that way. Don't ask me why the 40% number, it is just the number that the cell manufacturers give to us. There must be some scientific formula, with this 40% number, that helps to either prolong the self-discharge or deter it in some manner.

 

Regards,

Paul

[Alfeo Dixon SOC]

If you are leaving li ion batteries off of charge, then the best way to store them is to discharge them to approximately 40% of charge and let them sit that way. Don't ask me why the 40% number, it is just the number that the cell manufacturers give to us. There must be some scientific formula, with this 40% number, that helps to either prolong the self-discharge or deter it in some manner.

Does this still hold true? I was told to try and never let my Li Ion batts discharge more than 20% and to completely charge them before putting them alway... its a bit impractical for us to try and discharge our batts to 40% when we literally don't know when our next day will be. So what is the best way to handle this????

 

My original question upon finding this thread was to find the best solution on my battery rotation (especially in 24v or 12vParallel)? Should I use two older batteries together and two newer batts together or new and old at the same time?

 

 

[pauldudeck]

If you are leaving li ion batteries off of charge, then the best way to store them is to discharge them to approximately 40% of charge and let them sit that way. Don't ask me why the 40% number, it is just the number that the cell manufacturers give to us. There must be some scientific formula, with this 40% number, that helps to either prolong the self-discharge or deter it in some manner.

Does this still hold true? I was told to try and never let my Li Ion batts discharge more than 20% and to completely charge them before putting them alway... its a bit impractical for us to try and discharge our batts to 40% when we literally don't know when our next day will be. So what is the best way to handle this????

 

My original question upon finding this thread was to find the best solution on my battery rotation (especially in 24v or 12vParallel)? Should I use two older batteries together and two newer batts together or new and old at the same time?

 

Hi Alfeo,

 

Yes, this will always hold true for lithium ion batteries. Like you mentioned, it is virtually impossible for you to know exactly where 40% is, but do your best to be around the 50% mark. As far as the "20%" that you were referring to, I don't know where that came from, but I highly don't think that is true. For all intents and purposes, a lithium ion battery will only self-discharge around 1% per month, so you would need to let it sit around for 18+ months to let it self-dishcarge 20%. Now if someone is telling you not to use the battery for more than 20%, then that is really out of the ballpark. How would you be able to really use your battery if you cannot use it more than 20%? The other best way to store the battery is on the charger.

 

When we are referring to discharging a battery to 40% and leave it off charge, this is typically for a situation where you will not be using the battery for extended periods of time.......say 6 months or more. So, this is not an everyday thing to do.

 

As far as batteries of different ages, I would try and keep the same aged batteries together when using them. Most pieces of equipment do not know the age or run-time of each individual battery and will only draw from the battery/batteries based on the voltage. An older battery will have a lower voltage and the voltage will drop off quicker, so the piece of equipment would pull power from the stronger battery most of the time, until the voltage levels meet.

 

Hope that helps.

 

Paul

[Alfeo Dixon SOC]

As far as the "20%" that you were referring to, I don't know where that came from, but I highly don't think that is true. For all intents and purposes, a lithium ion battery will only self-discharge around 1% per month, so you would need to let it sit around for 18+ months to let it self-dishcarge 20%. Now if someone is telling you not to use the battery for more than 20%, then that is really out of the ballpark. How would you be able to really use your battery if you cannot use it more than 20%? The other best way to store the battery is on the charger.

I guess I used the wrong terminology... what I meant to say, is that I was told that it is bad to keep using your batteries below 20% of charge until completely drained.

[pauldudeck]

Hi Alfeo,

 

No, this is not true and if a battery company is telling you this, then you are paying for a battery that you can only use 80% of. All Lithium Ion batteries should have a low voltage shut-off circuit in them, usually around 10-10.5V. This will prevent the battery from over-discharging. If you did not know already, if you over-discharge a lithium ion battery one time, you can kill it. This is another one of the disadvantages of lithium ion. A NiCad or NiMH cell can be over-discharged, for all intents and purposes, many times without affecting the run-time or life.

 

Regards,

Paul