Reply to "How I reused a Sony InfoLithium battery!"
Camcorder-battery-shop.com 2006-11-03
A customer e-mail us:"I use a Sony TRV33E and two batteries, a NP-FM30 came with the camcorder when I bought, and a NP-FM50 bought after that. Last time I used my camcorder was Feb 2 with the NP-FM50 attached, when the NP-FM50 ran out, I put the whole set to locker. Then on March 11, I tried to use it forgetting that the NP-FM50 had run out. Of course, it didn't work. But, to my surprise, it still didn't work with the adapter connected. And the camcorder refused to charge the NP-FM50 , the battery LED on the camcorder flashing. I checked the NP-FM50 with a V.O.M meter, it gave 0V. Few days later, I used a simple AC-DC 7.5V adaptor to charge the NP-FM50 . It stored some electricity and was able to light a bulb. Then I attached it to my camcorder again. When I switched the camcorder on, it said "Use InfoLithium battery only" or some thing like that. So, I thought that the Info chip of the NP-FM50 was dead. To reuse it, I bound it to the back of the NP-FM30 with adhesive tape, connected their positive and negative poles parallel, then attached the FM30 to my camcorder. Switching it on, it worked. To check if the NP-FM50 is effective, I noted the remain time reported by the NP-FM30 : 96 minutes, used the camcorder for 15 minutes, then checked the remain time reported by the FM30 again: 92 minutes. Conclusion: The NP-FM50 adds capacity to the NP-FM30 , I can use both at the same time but the NP-FM30 can't know the existence of the NP-FM50 . What do you think?"
My answer is:
One of the primary purposes of the "Info chip" in Lithium Ion battery packs is as a protection circuit that limits the charge voltage most with temperature sensing to disconnect the charge if the cell temperature approaches 194°F (90°C), and a mechanical pressure switch on many cells to permanently interrupt the current path if a safe pressure threshold is exceeded. The safety circuit is also designed to cut off the current path if the battery is inadvertently discharged below 2.50 volts per cell which can make the battery fail.
Connecting another battery pack in parallel may cause unpredictable results. Lithium Ion batteries may ignite if improperly charged.
Lithium Ion batteries like many rechargeable batteries have "vents" to prevent pressure build-up so if they are charged or discharged too quickly they can heat up and the vent will open which makes the battery useless. Lithium Ion batteries can lose up to approximately 20% capacity per year from the time they are manufactured, even when unused. Typically after two to three years the battery will have capacities too low to be still usable.
Top Sony Camcorder Batteries
| NP-F550 | NP-F570 | NP-F730 | NP-F750 |
| NP-F770 | NP-F930 | NP-F960 | NP-F970 |
| NP-FA50 | NP-FA70 | NP-FF50 | NP-FF51 |
| NP-FF70 | NP-FF71 | NP-FM30 | NP-FM50 |
