I've mainly dealt with GNB & found there pretty decent, very rarely had any issues / failures & any problems we did have ( cell failed or charger fault ) where quickly sorted out by GNB.
Also dealt with Hawker EnerSys - about the same experience as GNB.
The only thing I don't like about either GNB or Hawker EnerSys is there awful battery filling system's, give me old fashioned cell flip tops & a topping up gun on the end of my topping up cart any day.
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