Cross not charging with powerbank



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    Thierry CHARLÈS


    Yes there may be surprises, with a PowerBank, it all depends on the state of charge or discharge of the GPS, when you connect it.

    TwoNav has evolved its specifications, initially the value mentioned was a capacity in ma/h (which is technically correct). Now it is noted as being an electrical charge value of the battery, but we do not specify a charge current in ma/h it is not a technical truth.

    Cross: 3300 ma/h
    Trail 2: 4000 ma/h

    And the load values ​​announced at the start corresponded to 0.5 x C

    Cross: 1.7A
    Trail 2: 2A

    I guess they got feedback. This being technically it is necessary to be able to provide 1 x C or 3.3 A for a CROSS and 4 A for a TRail 2

    I explain, the technology of a Li_ION battery (Reference data from the documentation of the charging component manufacturers), requires a charging cycle which has two main phases:

    1. The first with a high current, current which must be at least equal to 0.5 x C (battery capacity) i.e. for a CROSS (3300 ma/h) of 3.3 A x 0.5 = 1, 7 A (If the source can deliver 1x C or 3.3 A for a CROSS it's better, it allows the charger to recover an over-discharged battery).
    2. A phase where the current will drop rapidly and become weak

    What I observed:

    • If the GPS is very discharged (< 70%), the charge with a Power Bank of 24,800 ma/h able to protide 2.1 A  (Used with a Trail 2 batterie : 4000 ma/h) is working correctly, the charge is complete. If the GPS is charged more than 70% (approximately) when it is wired to the power bank, the Power Bank cannot charge it. It is likely that the power bank's internal logic, noting a relatively low starting current, considers that there is no more flow, either disconnects or limits the output current for internal protection reasons. And the GPS reacts accordingly.

    Do a test with the GPS at 50 or 60% it will probably work.

    However, the PowerBanks are "made in china" products, there is always a doubt about the ability of the made in china to comply with their specifications.


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    Xavier Tous

    Hello Thierry, 

    Thank you very much for your documented answer.

    I understand my powerbank fullfills the basic requirements but anyhow does not share the same logic of the Croos.

    Interesting your phrase " If the GPS is charged more than 70% (approximately) when it is wired to the power bank, the Power Bank cannot charge it."

    The result of my first attemp with GPS battery at 6% was RED led on for a few seconds.

    Today I tried the same with gps battery at 65% (close to your 70%) and the result was BLUE led on and gps went on operation. In both cases charging did not start.

    Seems to be related to the charge state perceived by the powerbank.

    Still in discussion with technical service. I will inform when I receive news

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    Xavier Tous

    No technical answer from service.

    I went to the shop to try powerbanks. I got something chineese but it works!

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