Hybrid battery repair, reconditioning and refurbishment

A Toyota or Lexus nickel-metal hydride pack is a series of modules wired together. The pack is only as strong as its weakest link, so a pack can fail because two or three modules have degraded while the rest are still serviceable.

1. 1The pack comes out and is disassembled down to individual modules.
2. 2Each module is tested — capacity, internal resistance, and how it holds voltage under load. This is the step that separates real reconditioning from a guess.
3. 3Weak modules are removed and replaced with tested modules matched to the rest of the pack.
4. 4The pack is charged, discharged and rebalanced so the modules start life together at the same state of charge.
5. 5Bus bars, connectors and the case are cleaned and inspected; corroded hardware gets replaced.
6. 6The pack goes back in, the system is reset and the car is road tested.

• The failure is clearly concentrated — a small number of blocks are dragging down a pack that is otherwise in reasonable shape.
• The rest of the vehicle is sound and you plan to keep it a few more years.
• You are trying to keep the car on the road on a tighter budget and understand the trade-off in expected service life.
• The pack has a good cooling history: clean intake, working fan, no evidence of chronic overheating.
• You want a lower up-front cost and accept a shorter warranty than a replacement pack carries.

• The whole pack has aged evenly — every module is tired, so swapping a few just moves the failure a few months down the road.
• There is evidence of chronic overheating, water intrusion, corrosion or rodent damage inside the pack.
• The pack has already been reconditioned once and has failed again.
• You drive a lot of miles, tow, or need the highest confidence for a long commute across the Valley.
• The difference in cost is small enough that the longer warranty on a replacement pack is the better value.