Recelling Batteries

Hello,

I'm recelling one of my Aaton batteries. It has Sanyo Cadnica N-1400mAh Nickel Cadmium batteries, 10 of them. Well, one got fried (I suppose) since it now only reaches around 9 volts.

So I'll replace all 10 (unless someone suggests finding out which one it is and replacing that one only) but a good search on the net seems to indicate these are now replaced by 1500 mAh ones (unless I have to search more) I found a place here that stocks Eveready ones (1500) and I was told this should be ok.

Could anyone substantiate this please?

I will continue net searching and appreciate your input as always. (I'm also going to open the other batteries I have and see if they all use Sanyo Nicd)

Best regards,
John Babl
Miami

Hi…John Babl writes :

>So I'll replace all 10 (unless someone suggests finding out which one it >is and replacing that one only)

Not a good idea, it'll be out of balance, and you'll end up with some batteries charging others, taking more current, overheating, etc.

>1500 mAh ones (unless I have to search more) I found a place here that >stocks Eveready ones (1500) and I was told this should be ok.

It's fine. The battery without the cells in is just a plastic case, it doesn't care. The only exceptions are either if you recelled it with enormously uprated cells and then tries to fast charge or discharge it at a greater rate than the contacts were designed to take, or if it has an active meter in it - the meter might then (and would probably) be unusable.

Personally I'd get the biggest cells I could for extra runtime.

I did exactly this when I first bought camera gear a year or two ago. I bought a charger with used batteries (state unknown) one of which was completely shot; I recelled it, uprating it from a somewhat feeble 12V 4Ah to a much more useful 14.4V 6Ah.

Been using it for ages, no problem.

Make isn't important either. Assuming you have different charging facilities, you can even change chemistry. You could, if you particularly wanted to, recell a NiCd battery with NiMH cells. In fact, I often wish I'd just bought the knackered old PAGs for £20 a shot and built a charger from an off the shelf unit and some PAG mounting plates, I could have had lithium batteries then.

Phil Rhodes
Video camera/edit
London

>You could, if you particularly wanted to, recell a NiCd battery with NiMH >cells

I was curious about that, since the NiMH seem to be the newer types, and use the same charger? I wonder if it is indeed a better choice to use them (size has to match to fit in the case too).

The SCR designation on the Sanyo seems to indicate it's a fast charge batt.

Still searching,

Thanks
John Babl

Hi, John Babl writes :

>I was curious about that, since the NiMH seem to be the newer types.

Better power to weight ratio, basically.

>And use the same charger?

Emphatically not, most of the time. Some NiCd chargers are smart enough to do it, but definitely assume not. You can buy charger modules; whip the guts out of your existing charger and use the same case with retrofitted electronics.

Phil Rhodes
Video camera/edit
London

>I was curious about that, since the NiMH seem to be the newer types. >Better power to weight ratio, basically.

One thing about NiMH is that they have a higher self-discharge rate than NiCad, that is to say if you charge them up and put them on a shelf, they will lose more of their charge faster than the NiCads...Not usually a problem, but might be if you are shooting while on an expedition and not accessible to chargers every day.

I don't know the percentage difference in self discharge but I know it is an issue

Mark Weingartner
LA based (not shooting nature)

Mark Weingartner wrote:

>One thing about NiMH is that they have a higher self-discharge rate than >NiCad

The self-discharge rate for NiCds is about 30% per month. NiMh are about 40%, last info I have. NiMh require more stringent controls for charging and Lithium Ion's requirements are very stringent.

Good reference:

http://www.antonbauer.com/handbook/handbook.html#CELL-

FORMULATION

Wade K. Ramsey, DP
Dept. of Cinema & Video Production
Bob Jones University
Greenville, SC 29614

The self-discharge rate for NiCds is about 30% per month. NiMh are about 40%, last info I have. NiMh require more stringent controls for charging and Lithium Ion's requirements are very stringent.

Thanks and thanks for reference...I thought there was a greater disparity.

Mark Weingartner

Mark Weingartner wrote:

>Thanks and thanks for reference...I thought there was a greater >disparity.

There used to be, in my experience. The first NiMh cells I bought (AA's) would be virtually exhausted a week after charging on the shelf. The ones I have now hold most of their charge for the better part of a month on the shelf.

I don't recall where I got that data (10% more self-discharge than NiCds) but it was from some sort of battery authority.

Wade K. Ramsey, DP
Dept. of Cinema & Video Production
Bob Jones University
Greenville, SC 29614

Phil Rhodes writes:

>You could, if you particularly wanted to, recell a NiCd battery with NiMH >cells

Yes, but you'd have to determine whether your charger can safely charge NiMH’s, which are MUCH more sensitive to overcharge than nicads are.

Without a properly matched charger you could radically shorten their life.

Dan Drasin
Producer/DP
Marin County, CA

>Yes, but you'd have to determine whether your charger can safely >charge NiMH’s…..Without a properly matched charger you could >radically shorten their life.

I inevitably ended up at a few sites that sell to the R/C industry (and Hobby stores). Who else uses more Nicads and Nimh batteries? There are indeed some chargers that you can set to recharge either of them.

http://www.batteriesamerica.com/newpage3.htm

(Navigate the site to look for chargers as well, if you care to)

So the Aaton uses the fast charge SCR type batteries, Sub C size (Arris use a different type and size, I don't know them).

The fast charge batteries can take the 1 hour charge for emergency situations, but the longer the better for the life of the batt. Sanyo apparently doesn't make the 1400 mAh SCR anymore, but Panasonic does.

They make this 1800mAh SCR :

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXTT17&P=0

And since AbelCine Aaton batteries are 1,8 AH (12 and 16 volts if you want them), I could recell them with these. Sanyo has the 1250, 1300, 1700 and 1900mAh SCR's.

Any other thoughts are welcomed

Best regards,

John Babl
Miami

I have to throw a comment in here about switching over from purpose-built Aaton batteries to NP type batteries to run the XTR.

Several suppliers manufacture an adapter to allow NP batteries to be used to power the Aaton 12 volt XTR/LTR cameras. The first one I ever used was made by Robert Norgard in San Francisco in the early 80s but now they are made by several outfits.

My favourite is from Oppenheimer in Seattle. It costs a bundle but seems to fit every Aaton I've ever tried it on and is very reliable. Plus it has the advantage of having a Lemo power socket built into the adapter thus allowing you to power current-hungry devices like onboard monitors, etc. without pulling all that current through the camera electronics.

This is a great feature.

The 12 volt NP batteries run the camera with color tap and Microforce for hours and there are a bunch of good inexpensive chargers to choose from. Although it is getting harder to find 12 volt NP type NiCad or NiMH batts these days, they are still available and much less expensive than purchasing new Aaton batts or often even recelling your old ones. As fantastic as most everything else is on the Aaton I've never been a fan of their own battery system.

The NP adapter system is a great alternative to consider.

Rod Williams
Motion Picture First Camera Assistant
Petaluma, California
U.S.A.