Watts On NP-F970? at DVinfo.net

Richard Zlamany · January 11th, 2006, 10:46 PM

Hello.

How many watts is a NP-F70 sony battery?

If someone has this battery could they please check. It is written on the battery most of the time.

Kawai Sin · January 12th, 2006, 12:20 AM

it reads 47.5Wh

Marcus Marchesseault · January 12th, 2006, 12:31 AM

Don't forget that if you put a heavy load on a battery and drain it at it's specified rating that it will have lesser output. Batteries are rated for a slower rate of drain. I know, it's stupid. I didn't make up the rules.

If you have a 47W light on a 47Whour battery, it will die in less than an hour.

Richard Zlamany · January 12th, 2006, 12:43 AM

Thanks for answering.

I have a strange problem. I bought a new sony NP-F970 but when I plug it into the sony 10/20 watt light it goes out in 5 minutes. It is fully charged and works in the camera as usual but not the light. When I try another battery the light works fine. The battery is fine in all regards save the light.
Flicking the switch on the light powers it up for another 5 minutes.

I wonder why this would happen. It looks like a genuine Sony battery but I did buy it off of ebay.

It only happens when I use the light in the 20 watt mode. In the 10 watt mode the light works.

Lou Bruno · January 12th, 2006, 07:52 PM

There is a chip within the battery that causes the battery to appear to drain if overheated. Next time, take the battery out of the light and let it cool down.

Quote:

Originally Posted by Richard Zlam

Thanks for answering.

I have a strange problem. I bought a new sony NP-F970 but when I plug it into the sony 10/20 watt light it goes out in 5 minutes. It is fully charged and works in the camera as usual but not the light. When I try another battery the light works fine. The battery is fine in all regards save the light.
Flicking the switch on the light powers it up for another 5 minutes.

I wonder why this would happen. It looks like a genuine Sony battery but I did buy it off of ebay.

It only happens when I use the light in the 20 watt mode. In the 10 watt mode the light works.

Giroud Francois · January 12th, 2006, 08:40 PM

yes, in the cabling between the cell, there is a kind of thermal fuse.
since in 20w mode you are trying to get half of current and in 10W mode, only a quarter, it seems the battery is designed to drain between these 2 values. (around 12-15W).
do not forget that these high capacity batteries are supposed to power a camera for several hours.

Richard Zlamany · January 12th, 2006, 09:22 PM

Interesting.

The battery is not hot but warm. When it is warm it lasts for 10 seconds.

When I use a non sony NP-F970 battery it lasts for hours and gets hot without turning off.

What battery am I suppose to use with the Sony 10/20 watt sony light. The sony should last more than 5 minutes.

Ironically the non Sony NP-F970 battery works for hours without a hitch and cost less than the sony which works for 5 minutes.

Shouldn't the Sony battery work better than the non Sony battery?

Does anyone use the Sony NP-F970 with Sony 10/20 light with success?

Sorry this may be in the wrong forum but the light is for a pd170 as are the batteries

Kawai Sin · January 12th, 2006, 11:04 PM

Be careful of non-Sony batteries exploding.

Richard Zlamany · January 13th, 2006, 10:21 PM

I am taking the chance, since the non sony batteries operate the light longer than 5 minutes. What other choice do I have save to buy a new light.

David Ennis · January 14th, 2006, 10:20 AM

A battery rating of 47.5 watthours does not mean the NP-F970 can deliver 47.5 watts for an hour. And a rating of a Sears Diehard battery of 230 Amphours does not mean it can deliver 230 amps for an hour. These ratings really indicate how much charge the battery can store. The power at which they can deliver it is a matter of fairly involved chemistry and physics. Camcorder batteries, especially infolithium batteries also contain electronic controls that complicate the picture further.

The NP-F970 stores enough charge to power your 20W light for several hours, but is not designed to do so. It is designed to power a cam for up to 18 hours. That's more like 2 to 3 watts. If you ask it to power a 10 watt device, you're pushing it. No suprise that it cuts off quickly at 20 watts.

To get the best battery for your light, I'd go to one of the big online battery suppliers with obvious names like batteries.com, and maybe give them a call.

Richard Zlamany · January 14th, 2006, 12:56 PM

Thanks Fred. That clears it it up.

Richard Zlamany · January 21st, 2006, 09:19 PM

An update:

I bought the battery from carolgift on ebay. It didn't work with my light. So I decided to use with my camera at a reception today.

In the middle of the chicken dance song (there was a lot of children) the battery died even though 270 min remained seconds before its death.

A bad, new, genuine sony, ebay bought battery is the cause of this thread.

Sean Bouchard · January 30th, 2006, 08:00 AM

Just to give some info on video camera batteries...

The Li-ion battery packs use a very complicated managment chip inside the pack. This chip checks everything from current draw, remaining power and measures the voltage of EACH cell inside the pack.

The reason that there is a management chip is to protect the cells (and yourself) from damage. Li-ion cells must not be discharged below 2.8 volts (per cell) or they will lose capacity. Also the chip prevents the cell from being shorted (due to improper use, or battery damage) leading to overheating and possibility exploding.

Li-ion batteries have a very high internal resistance meaning that when you draw a lot of current from them (such as video lights) the cells see a large voltage drop across them. If any one of the cells inside the battery pack are unmatched (cells are matched at the factory) or have lost capacity due to manufacturing defect, age, etc... the management chip will detect the sudden drop in voltage (across a cell) and turn off the battery pack.

This is what you are seeing with that battery and the light. Basically the only thing you can do to try and get the battery to work properly is leave it on the charger for atleast 12 hours.

If the battery shuts off on you when you are using it on the camera with that much "estimated" time left, then there is something fishy going on with it, I would guess a bad cell. Li-ion batteries normally have a very linear discharge rate.

anyway I hope that wasn't too much info (I've done a lot of research on li-ion technoogy)

Richard Zlamany · January 30th, 2006, 06:34 PM

Thanks. Your post was helpful.

January 11th, 2006, 10:46 PM	#1
Richard Zlamany Major Player Join Date: Jun 2005 Location: Hamden CT Posts: 470	Watts On NP-F970? Hello. How many watts is a NP-F70 sony battery? If someone has this battery could they please check. It is written on the battery most of the time.

January 12th, 2006, 12:20 AM	#2
Kawai Sin New Boot Join Date: Oct 2005 Location: Zoo York Posts: 20	it reads 47.5Wh __________________ Kawai Sin www.rollingedit.com

January 12th, 2006, 12:43 AM	#4
Richard Zlamany Major Player Join Date: Jun 2005 Location: Hamden CT Posts: 470	Thanks for answering. I have a strange problem. I bought a new sony NP-F970 but when I plug it into the sony 10/20 watt light it goes out in 5 minutes. It is fully charged and works in the camera as usual but not the light. When I try another battery the light works fine. The battery is fine in all regards save the light. Flicking the switch on the light powers it up for another 5 minutes. I wonder why this would happen. It looks like a genuine Sony battery but I did buy it off of ebay. It only happens when I use the light in the 20 watt mode. In the 10 watt mode the light works. Last edited by Richard Zlamany; January 12th, 2006 at 01:19 AM.

January 12th, 2006, 11:04 PM	#8
Kawai Sin New Boot Join Date: Oct 2005 Location: Zoo York Posts: 20	Be careful of non-Sony batteries exploding. __________________ Kawai Sin www.rollingedit.com

January 14th, 2006, 10:20 AM	#10
David Ennis Fred Retread Join Date: Jul 2004 Location: Hartford, CT Posts: 1,227	A battery rating of 47.5 watthours does not mean the NP-F970 can deliver 47.5 watts for an hour. And a rating of a Sears Diehard battery of 230 Amphours does not mean it can deliver 230 amps for an hour. These ratings really indicate how much charge the battery can store. The power at which they can deliver it is a matter of fairly involved chemistry and physics. Camcorder batteries, especially infolithium batteries also contain electronic controls that complicate the picture further. The NP-F970 stores enough charge to power your 20W light for several hours, but is not designed to do so. It is designed to power a cam for up to 18 hours. That's more like 2 to 3 watts. If you ask it to power a 10 watt device, you're pushing it. No suprise that it cuts off quickly at 20 watts. To get the best battery for your light, I'd go to one of the big online battery suppliers with obvious names like batteries.com, and maybe give them a call. __________________ "Nothing in the world can take the place of persistence..." - Calvin Coolidge "My brain is wired to want to know how other things are wired." - Me

January 12th, 2006, 12:31 AM	#3
Marcus Marchesseault Trustee Join Date: Nov 2005 Location: Honolulu, HI Posts: 1,961	Don't forget that if you put a heavy load on a battery and drain it at it's specified rating that it will have lesser output. Batteries are rated for a slower rate of drain. I know, it's stupid. I didn't make up the rules. If you have a 47W light on a 47Whour battery, it will die in less than an hour.

January 12th, 2006, 08:40 PM	#6
Giroud Francois Inner Circle Join Date: Feb 2004 Location: switzerland Posts: 2,133	yes, in the cabling between the cell, there is a kind of thermal fuse. since in 20w mode you are trying to get half of current and in 10W mode, only a quarter, it seems the battery is designed to drain between these 2 values. (around 12-15W). do not forget that these high capacity batteries are supposed to power a camera for several hours.

January 12th, 2006, 09:22 PM	#7
Richard Zlamany Major Player Join Date: Jun 2005 Location: Hamden CT Posts: 470	Interesting. The battery is not hot but warm. When it is warm it lasts for 10 seconds. When I use a non sony NP-F970 battery it lasts for hours and gets hot without turning off. What battery am I suppose to use with the Sony 10/20 watt sony light. The sony should last more than 5 minutes. Ironically the non Sony NP-F970 battery works for hours without a hitch and cost less than the sony which works for 5 minutes. Shouldn't the Sony battery work better than the non Sony battery? Does anyone use the Sony NP-F970 with Sony 10/20 light with success? Sorry this may be in the wrong forum but the light is for a pd170 as are the batteries

January 13th, 2006, 10:21 PM	#9
Richard Zlamany Major Player Join Date: Jun 2005 Location: Hamden CT Posts: 470	I am taking the chance, since the non sony batteries operate the light longer than 5 minutes. What other choice do I have save to buy a new light.

January 14th, 2006, 12:56 PM	#11
Richard Zlamany Major Player Join Date: Jun 2005 Location: Hamden CT Posts: 470	Thanks Fred. That clears it it up.

January 21st, 2006, 09:19 PM	#12
Richard Zlamany Major Player Join Date: Jun 2005 Location: Hamden CT Posts: 470	An update: I bought the battery from carolgift on ebay. It didn't work with my light. So I decided to use with my camera at a reception today. In the middle of the chicken dance song (there was a lot of children) the battery died even though 270 min remained seconds before its death. A bad, new, genuine sony, ebay bought battery is the cause of this thread.

January 30th, 2006, 08:00 AM	#13
Sean Bouchard New Boot Join Date: Sep 2005 Location: Thunder Bay, Canada Posts: 18	Just to give some info on video camera batteries... The Li-ion battery packs use a very complicated managment chip inside the pack. This chip checks everything from current draw, remaining power and measures the voltage of EACH cell inside the pack. The reason that there is a management chip is to protect the cells (and yourself) from damage. Li-ion cells must not be discharged below 2.8 volts (per cell) or they will lose capacity. Also the chip prevents the cell from being shorted (due to improper use, or battery damage) leading to overheating and possibility exploding. Li-ion batteries have a very high internal resistance meaning that when you draw a lot of current from them (such as video lights) the cells see a large voltage drop across them. If any one of the cells inside the battery pack are unmatched (cells are matched at the factory) or have lost capacity due to manufacturing defect, age, etc... the management chip will detect the sudden drop in voltage (across a cell) and turn off the battery pack. This is what you are seeing with that battery and the light. Basically the only thing you can do to try and get the battery to work properly is leave it on the charger for atleast 12 hours. If the battery shuts off on you when you are using it on the camera with that much "estimated" time left, then there is something fishy going on with it, I would guess a bad cell. Li-ion batteries normally have a very linear discharge rate. anyway I hope that wasn't too much info (I've done a lot of research on li-ion technoogy)

January 30th, 2006, 06:34 PM	#14
Richard Zlamany Major Player Join Date: Jun 2005 Location: Hamden CT Posts: 470	Thanks. Your post was helpful.