Baterai memiliki peranan penting dalam suatu gardu traksi kereta api, yang dimana ketika sumber utama dari PLN mengalami gangguan / padam, baterai berfungsi sebagai sumber utama tegangan control relay-relay pengoperasian dan proteksi yang ada di dalam gardu traksi. Pada kondisi tersebut gardu traksi tidak menghasilkan tegangan 1500 Vdc dan hanya bertindak sebagai gardu penghubung antar gardu-gardu disebelahnya. Guna memastikan kesiapan operasi baterai sebagai back up supply DC, maka dari itu dilakukan pengukuran tegangan per- cell baterai, hambatan dalam serta pengujian pembebanan guna mengetahui performa baterai di gardu traksi stasiun kalideres. Setelah didapatkan hasil dari pengujian pembebanan yang dilakukan selama 5 jam, data yang didapat kemudian diolah dengan menggunakan metode regresi linier guna memperkirakan berapa lama waktu maksimum baterai dapat memback up beban-beban DC yang ada di dalam gardu traksi hingga mencapai tegangan total minimumnya yaitu 108 Vdc. Berdasarkan pengukuran dan pengujian serta pengolahan data yang dilakukan, pada baterai leoch dihasilkan tegangan total baterai berada di atas standar referensi dan diperkirakan mampu melayani beban selama 7 jam. Akan tetapi hambatan dalam baterai berada dalam kondisi fail dan sudah nelewati batas standar referensi yang ditetapkan sehingga perlu dilakukan rekondisi / penggantian baterai. Hasil pengujian pembebanan setelah rekondisi dihasilkan tegangan dan nilai hambatan dalam per- cell baterai berada dalam kondisi baik dan diperkirakan baterai mampu melayani beban-beban DC sebesar 5,40 A selama 40 jam dengan total tegangan akhir sebesar 108,008 Vdc.

Batteries have an important role in a railway traction substation, where when the main source of PLN is interrupted / extinguished, the battery serves as the main source of voltage control for operating and protective relays in the traction substation. In these conditions the traction substation does not produce a voltage of 1500 Vdc and only acts as a connecting substation between adjacent substations. In order to ensure the readiness of battery operation as a DC back-up supply, therefore, measurements of the per cell battery voltage, internal resistance and loading tests are carried out to determine battery performance at the Kalideres station traction substation. After getting the results from the loading test carried out for 5 hours, the data obtained is then processed using the linear regression method to estimate how long the maximum time the battery can back up DC loads in the traction substation until it reaches its minimum total voltage of 108 Vdc. Based on the measurements and tests and data processing carried out, the leoch battery resulted in the total battery voltage being above the reference standard and is estimated to be able to serve the load for 7 hours. However, the resistance in the battery is in a fail state and has passed the reference standard limit set so that it is necessary to recondition/replace the battery. The results of the loading test after the reconditioning resulted that the voltage and resistance values in the battery cell were in good condition and it was estimated that the battery was able to serve DC loads of 5.40 A for 40 hours with a total final voltage of 108.008 Vdc.