depleted batteries

I have neglected my camcorder batteries and have now found they will not charge. They are Sony NP-FM50's and are charged in camera. They sre Li-ion type.

Has anyone any idea if I can resurrect them. I have ordered a new one but the originals I bekieve have a sensing circuit in them.

Clive

Hi Clive

Do you have a generic charger? some users have posted videos and have found it will charge a battery that Mr Sony rejects. It outsmarts the smart (SIC) chip.

**LINK**

Regards
John

I think Johns link was trying to show a video but for some reason i cant upload a working link to it and all i got were ads .

I would hook up a variable power supply running to the positive and negative terminals and run it at the battery voltage via a 10 ohm 25 w resistor and give it a tickle - do it outside though just incase something goes belly up ! If things start getting hot turn it off ! The sensing circuit inside the camcorder is reading a voltage below its cut off threshold and won't recognise the battery until its voltage is above this .

Edited By XD 351 on 11/01/2019 04:36:49

Edited By XD 351 on 11/01/2019 04:39:23

Edited By XD 351 on 11/01/2019 04:41:08

Edited By XD 351 on 11/01/2019 04:43:20

ebay sell replacement batteries and chargers for Sony NP-FM50. They are not expensive.

Paul.

The link to a Google search worked fine here, anyway try these:

One UK one state side.

**LINK**

**LINK**

I had read of this problem with Sony before.

Yes Youtube puts an adv in front of many videos, not a bug just a pain in the a...s

Regards
John

Edited By John McNamara on 11/01/2019 07:29:41

Thank you for the prompt replies about these sensing batteries. I will buy one of those chargers in the video I think. I will report back how it goes.

Clive

Li-ion batteries should not be discharged below a certain voltage otherwise permanent damage will result.

I used to work in IT and had lots of Li-ion phone batteries that would not charge, simple slution was to apply pulses of 12v to the battery by repeatedly tapping the 12v pos to the Li-ion pos.Once you get the battery above it's minimum, the original charger would take over.

you do this at your own risk of course.

I would get a replacement battery myself if it is for camera use, plenty of batteries on ebay.

never had a problem with 3rd party batteries on any of my cameras.

Brand I use is EXPRO, not the cheapest but good capacity and fully compatable.

I saw a video on YouTube about someone with the same problem

He discharged them (if not already) then put them in the freezer for 24 hours then let them defrost well then recharge in the normal way

Then all was good (apparently)

If you can access the cells directly there are inexpensive charger modules that can safely bring them up to a voltage where the built in charger will work.

Another approach is repeatedly trying to charge, as if each time a small test charge is applied the battery may eventually recover.

Neil

Neil please tell me details about that module and from where it can be obtained. I usually follow an idea from ETI magazine (remember it) and ZAP my cells for the cordless power tools, it usually works but do get failures. John

John, how old was the article and was it for Li-ion or Nicad/Nimh. Apologies if you are already aware of the following, which isn't applicable to Li-ion;

My way for the latter was to charge up a capacitor bank and flash discharge/zap across the cell terminals, having established which one(s) in the battery pack were faulty.

This is for a different reason though; it's to fuse out the whiskers that can develop internally in each individual cell.

When charging, the charge current passes through the whisker, which effectively shorts out that NiCad cell. The surrounding cells charge up, but not that one. Zapping the cell with a short high current blast burns out the whisker, just like blowing a fuse, and the cell can once again accept charge.

Much safer than the other method I've read about where folks use a car battery to zap a cell; there's far to much reserve energy available there.

Bill

Anything based on a TP4056 chip should work, expect to pay about 20p each (normally sold in batches of 10 boards). They have a connection for the thermistor to monitor the temperature of batteries and have some excellent features. The downside is they are strictly for 4.2V packs only:

• Manage the constant current to constant voltage charging of a connected lithium battery
• Over-discharge protection - keeps your battery from being discharged below 2.4V, a healthy minimum voltage level for your battery
  • If a connected battery has been discharged below 2.4V the module will cut output power from the battery until the battery voltage has been re-charged above 3.0V (the over-discharge release voltage), which at that time the module will again allow discharge of power from the battery to a connected load. Although the module cuts output power from the battery during an over-discharge situation, it still allows charging of the battery to occur through the parasitic diode of the discharge control MOSFET (FS8205A Dual MOSFET).
• Overcharge protection - the module will safely charge your battery to 4.2V
• Overcurrent and short-circuit protection - the module will cut the output from the battery if the discharge rate exceeds 3A or if a short-circuit condition occurs
• Soft-start protection limits inrush current
• Trickle charge (battery reconditioning) - if the voltage level of the connected battery is less than 2.9V, the module will use a trickle charge current of 130mA until the battery voltage reaches 2.9V, at which point the charge current will be linearly increased to the configured charge current.

A replacement NP-FM50 battery has just arrived, I put it in the camera and it works OK. Now charging until the light goes out.

The battery casing is identical in everyway to the original Sony battery casing ! No mark of origin/maker but obviously a clone battery. The output is slightly lower at 1700 ma instead of 1800ma. That does not bother me as if I can get the other two batteries up all will be well. I will have a quick look at other suppliers to see if their batteries have higher capacity.

Thank you for the clear and concise details of charging, I will be careful. 

Clive

Edited By Clive Hartland on 11/01/2019 14:30:07

I have found that it is possible to get clone batteries for Canon cameras with much higher capacity, but a shorter lifetime, from the USA.

N.

The battery charger arrived today and I put the first battery on charge, after 4 hours charge I tested the voltage and it is no good. The battery was slightly warm. Have now put the 2nd battery on charge and will test later this evening.

Checking the life of the NEW battery i bought it has, after a full carge 123 minutes of service.Camera is working fine.

Clive

1840 hrs, the 2nd battery has been on charge for a while and I have measured 8.6 v between the terminals so I assume that one is OK.

The camera will now be able to charge it as it above the threshold voltage to charge.

Clive

PS. the 2nd battery did not get warm !  the chager is giving 500 mA

Edited By Clive Hartland on 14/01/2019 18:47:41