about Battery

  • Erm...
    I'm sure it's not so good to press 2A into the device. ;)

    High charge voltages, excessive charge rate and extreme load conditions will have a negative effect and shorten the battery life. This also applies to high current rate lithium-ion batteries.

    Keep the lithium-ion battery cool!! Avoid a hot car!! For prolonged storage, keep the battery at a charge level of 40%!
    When you don't use it, you can keep it into you refrigerator! (No joke!!) [Keep it dry! ;)]

    You can use this for charge:
    [Blockierte Grafik: http://img207.imageshack.us/img207/3360/imageresizersx1.jpg]
    1000mA :)

    The best is, when put it over night on your USB-PC-Port. :) [500mA]

    I'found this:
    [Blockierte Grafik: http://img207.imageshack.us/img207/77/parttwo34xh2.gif]


    Einmal editiert, zuletzt von JaKe2kOnE ()

  • Again: Current is never pressed into device! It's an offer.

    The charge circuit determines the max charge current in dependence of capacity of used lithium-ion battery.

    Important is the voltage of 5V. Lithium-ion cells are charging to 4.2 volts. Overloading above 4.3V causes the cell to heat up.

    Your selected device is very suitable and perfect for our 7934...

  • Okay, I have to correct my statement:


    I'm sure it's not so good to "press" 2A into the device.

    Damnit, I thought here are no nitpiker. ;) :P
    I'm just a stupid electronics technician for communication technology, I don't have to know it.

    And I still claim you'll destroy your battery in the long run, using this charger.
    And, I'm sure 5V @ 2A are used by 4-Port USB-HUBs.

    Too much for charging, if the device will get/take it, or not.

    The negative effects by using a (too) high charge voltage, charge rate or load conditions are facts and cannot be argued away.


    Normally a fast charge, rather than a slow overnight charge, will result in a shorter battery lifespan.



    Capacity improvement or Quick charging will always decrease the number of cycles.


    Einmal editiert, zuletzt von JaKe2kOnE ()

  • We don't have NiMH or NiCd, we're using lithium-ion-cells!

    The internal charge circuit of 7934 is the only one which controlls charge technique and nobody said, that this works in so called fast-charger-mode.
    (BTW: this mode doesn't exist)


    or german:

    Increasing the charge current does not shorten the charge time by much. Although the voltage peak is reached quicker with higher charge current, the topping charge will take longer.

    Some chargers claim to fast-charge a lithium-ion battery in one hour or less. Such a charger eliminates stage 2 and goes directly to 'ready' once the voltage threshold is reached at the end of stage 1. The charge level at this point is about 70%. The topping charge typically takes twice as long as the initial charge.

    2 Mal editiert, zuletzt von RolloS60 ()

  • Sorry guys, I do not wanna cause a "forum war" ;)

    In back there is:

    ZUM BEISPIEL FUR\FOR EXAMPLE FOR : Garmin i3, TomTom v2, Becker 7988 , etc...

    Now I have more doubts... take it and try it or not ??? ?(


    Ehm...my opinion was : respect output 5V ! ...rest is just minus charging time (with no other WRONG effects)

  • Zitat

    Original von jobocu4
    Sorry guys, I do not wanna cause a "forum war" ;)

    Don't worry. Jake is my 'Buddy' and friend...really

    Take it and you'll be happy...i'm using a similar device with 5V 2A ... it works like a charm.

    Einmal editiert, zuletzt von RolloS60 ()

  • I have to correct myself!
    I'd used wrong sources, they was not for li-io. I thought they are generally, but my engineering data reference book is too old. :gap

    But, there is a contradiction: Higher charge rates releases more heat. We are seeing eye to eye that heat is counterproductively, right?

    So in every way, it's better to charge gently. :gap

    btw: Rollo is my "board fellow". :D Never fear!

    Einmal editiert, zuletzt von JaKe2kOnE ()

  • ...All we need is love...papparapparàààààààààà :D

    I know boys we are all a great community :) and good guys with good suggestions :D


    So in every way, it's better to charge gently. :gap

    So... in conclusion.... I will take it :) but I think is better to disconnect when the recharge is done and NOT to let it more connected, in way to avoid heat when there is no much more need. ;D

  • Ok here I am again :)

    With GREAT collaboration by RolloS60 I post some simple conclusions about battery point by point:

    1) Typical recharge Li-Ion = about 3 hours (see upper diagram)

    2) No memory effect

    3) USB (500mA) is not the "proper" method (= just a little bit longer) for recharging because it has a long STEP1 ...but obviously is a right one.

    4) Respect always 5V !!

    5) 5v 2A (AC\DC) devices (ex. HAMA) are "faster" in re-charging time because they "ignore" STEP 2, so that 70% is reached in approximately 1 hour and is useful to let BECKER work properly..... ----------- BETTER SAY :

    - 7934 has its own internal circuit (as others Li-Ion) to let the recharge going properly, and these "fast" AC\DC are quite an illusion...however they give a stable V for a good recharge.

    Thanks :D

    Einmal editiert, zuletzt von jobocu4 ()

  • Das ist ja ein langer Thread, nur zu diesem kleinen Thema!
    Nun setze ich noch eins drauf: Ich habe ein Ladegerät, dessen Stecker und Werte zum Navi passt, kann ich im Umkehrschluss das Auto-12V-Netzteil des 7934 zum Laden meines Handys benutzen?

  • Das Becker-Kfz-Adapter-Netzteil setzt die 12V intern nochmal auf 5V um.
    Wenn dein Handy mit Mini-USB ( Pin1 +5V, Pin5 GND ) geladen werden kann, wirst du es problemlos einsetzen können.

    I don't agree with pt. 5. So called "fast charging" is only controlled by internal circuits of Li-Ion-batteries and circuits inside our 7934.

    Einmal editiert, zuletzt von RolloS60 ()