Rebuild or Replace Calculator
Compare the real cost of rebuilding a tool pack with new cells against buying a replacement.
A rebuild is only worth it when it costs clearly less than a replacement and the pack is safe to open. Tick any warning signs first, then add up the costs. Everything is worked out in your browser. Nothing is saved or sent anywhere.
1. Check the pack first
Tick anything that applies. Any one of these means don't rebuild.
2. Rebuild costs
Use real prices from a reputable cell supplier. Cheap cells are often counterfeit or rewrapped.
A 5Ah 18V pack is usually 10 cells. The Cell Layout Calculator can work it out.
0 if you're doing it yourself with your own spot welder.
3. Replacement pack
Check for kits and sales. A pack bundled with a charger can cost little more.
4. Results
How it was worked out
What this does and doesn't tell you
- This compares money only. A new genuine pack comes with a warranty and fresh electronics. A rebuilt pack has neither, and it's your responsibility, not the tool maker's.
- The verdict uses a simple rule: a rebuild under half the cost of a new pack is worth considering, 50–70% is borderline, and over 70% isn't worth the risk.
- Cells must be joined by spot welding, not soldering. Heat from a soldering iron can damage cells. If you don't own a spot welder, include a repairer's fee or the cost of the gear.
- Lithium-ion tool packs can short, overheat and catch fire if they're damaged, wired wrongly or charged on the wrong charger. Only use the maker's charger for the pack, and recycle any pack that is swollen, burnt, leaking, crushed or has been in water.
Next steps
Read Is a Battery Pack Rebuild Worth It? before you open anything, and check the cell count with the Cell Layout Calculator.