• Login
    View Item 
    •   FFI Publications Home
    • Publications
    • Rapporter
    • View Item
    •   FFI Publications Home
    • Publications
    • Rapporter
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Sakkyndigrapport etter inspeksjon av et nikkel metallhydridbatteri som hadde vært årsak til en brann

    View/Open
    15-02397.pdf (972.4Kb)
    Date
    2016-02-05
    Author
    Hasvold, Øistein
    Metadata
    Show full item record
    Abstract
    FFI ble anmodet av IF forsikring ved Reidar Skrunes om å bidra til at årsaken til at en Apollo undervannsscooter brant opp under lading av batteriet ble avklart. Batteriet var bygget opp av 20 stk. NEXcell DD celler. Det ble sendt til FFI og inspisert i nærvær av importøren av scooteren (DACON AS, ved Tor Gundersen), IF og personell fra FFI. Lading av nikkelmetallbatterier termineres vanligvis ved at man måler en temperaturstigning på batteriet. I dette tilfellet fungerte ikke det, enten fordi temperatursensoren i batteriet feilet eller fordi kretsen i laderen som leser temperaturen ikke fungerte. Laderen ble ikke kontrollert av FFI. Overlading av et nikkelmetallhydridbatteri skal normalt bare føre til at batteriet blir ødelagt ved at cellene tørker ut og/eller kortslutter, men i dette tilfellet blåste en celle ut slik at innholdet ble eksponert mot luft. Kannen ble funnet i garasjedøren og var tom. I følge Energizer (som lager tilsvarende celler) er oppladet metallhydrid pyrofort, dvs. tenner spontant i nærvær av luft.
     
    Norwegian Defence Research Establishment (FFI) has been working on battery safety for many decades. Reidar Skrunes from IF Insurance asked if FFI could assist on a fire investigation where a battery in an Apollo DPV (underwater scooter) was suspected to be the cause of the fire. (DPV = Diver Propulsion Vehicle). The battery (24 V/20 Ah) was composed of 20 DD nickel metal hydride cells. The battery was sent to FFI and inspected in presence of the importer of the DPV, DACON AS and IF insurance. End of charge of nickel metal hydride batteries is commonly determined by an increase in cell temperature. The temperature increase is used to turn off the charger. In this case, the charging was not terminated; either because the temperature sensor did not work or the circuit in the charger measuring the temperature did not work. FFI did not analyze the charger. Normally, overcharge of NiMH only results in destruction of the battery cells from venting of gas, drying out of the electrolyte and internal short. In this case however, one cell vented violently. The cell can was found in the garage door and was empty. According to Energizer which makes similar cells, charged metal hydride burns spontaneously if brought into contact with air.
     
    URI
    http://hdl.handle.net/20.500.12242/1224
    Collections
    • Rapporter

    Browse

    All of FFI PublicationsCommunities & CollectionsBy Issue DateAuthorsTitlesThis CollectionBy Issue DateAuthorsTitles

    My Account

    Login

    CONTACT US

    • FFI Kjeller
      FFI, PO Box 25, 2027 Kjeller
    • Office Address: Instituttvn 20,
      Phone 63 80 70 00
    • biblioteket@ffi.no

    HELPFUL

    • About FFI
    • Career
    • Reports

    Sitemap

    • About cookies (cookies)
    • Newsletter
    • Sitemap

    FOLLOW US

     

     

    © Copyright Norwegian Defence Research Establishment
    Powered by KnowledgeArc