Connect with us

What type of batteries should I use?

Discussion in 'Troubleshooting and Repair' started by Pascal666, Feb 26, 2014.

  1. Pascal666

    Pascal666

    18
    0
    Aug 20, 2012
    I only use my fiber cable test set every other year or so. Charging them the day before I need them doesn't seem to work. It looks like the batteries self-discharge over the intervening years and cannot be recharged.

    The units came with 4.8v 600mAh NiCd battery packs (4 AA cells) soldered to the PCBs inside each sealed unit and 6v 300ma chargers. The different units use two different battery pack configurations, one flat and one square.

    I'd like to replace the battery packs but am having trouble figuring out what type to use. Any suggestions?
     
  2. jpanhalt

    jpanhalt

    426
    4
    Nov 12, 2013
    NiCd's are about the worst for self discharge. Newer NiMH are very good, but after a year, you may need to charge them. I use Sanyo eneloop. There are other brands that also claim very low self-discharge.The ones in my models last for at least 6 months and are still usable, but I still recharge them before flying.

    Is there any current draw during storage? A little trickle can do a lot over 12 months.

    John
     
  3. Pascal666

    Pascal666

    18
    0
    Aug 20, 2012
    I doubt there is current draw in storage. Each unit has a power switch.

    By "after a year, you may need to charge them" do you mean they will no longer take a charge if I do not charge them yearly or they simply will have no charge left after a year?

    I don't mind the batteries being fully discharged after sitting for a couple years, I would expect that, but I need a type that can then be recharged. It looks like NiCd's can't be recharged after sitting dead for years.
     
  4. jpanhalt

    jpanhalt

    426
    4
    Nov 12, 2013
    I forget the exact details, but let's say a four-cell battery pack is made of 2300 mAh batteries. After six months storage, I recharge them, and they take something like 300 mAh, i.e., 13% loss. One could certainly use them at that point, but why risk a $1000+ model when it is so easy to recharge. They are supposed to keep charge for a year, and I suspect that is true. I should also note that even after only a week or two of storage, my charger will show a minimum of about 200 mAh added.

    I would not be concerned that they would become flat and non-chargeable after a year.

    John
     
  5. Pascal666

    Pascal666

    18
    0
    Aug 20, 2012
    Over what time frame would you be concerned?

    Would I be able to use the original chargers? Though I use the word loosely, as far as I can tell they are really just dc power supplies. Is it possible to overcharge NiMH's?
     
  6. jpanhalt

    jpanhalt

    426
    4
    Nov 12, 2013
    I am always concerned. That is why I test things before relying on them.

    Don't see why not. When I bought mine, I just bought batteries, not a charger.

    Loosely? What else are you thinking of?

    Yes, don't do it.

    John
     
  7. Pascal666

    Pascal666

    18
    0
    Aug 20, 2012
    I meant how often would I have to take them out of storage to charge them so I don't have to worry about them not taking a charge next time I need them.

    All of my other chargers monitor the charge level of the battery or battery pack and automatically shut off once it is full.

    So if I just connect the new battery packs to the dc power supplies, how will I know when they are full?
     
  8. davenn

    davenn Moderator

    13,264
    1,749
    Sep 5, 2009
    John is telling to use a proper NiMH charger

    Dave
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-