20Ah SCiB LTO Battery Banks: Capacity and Current Sharing
The 20Ah label describes an individual Toshiba SCiB cell. It does not describe the capacity of every bank built from that cell. For car audio, the useful questions are how many cells are connected in series and parallel, how much current the bank must supply, and how quickly the charging system can replace the energy used.
Cell capacity versus finished bank capacity
Connecting cells in series adds voltage while retaining the amp-hour capacity of one cell. Connecting matched cells in parallel adds capacity and shares current. In a 6S4P arrangement, six series groups each contain four parallel 20Ah cells: 24 cells in total and 80Ah of bank capacity.
| Bank capacity | Arrangement | Total cells |
|---|---|---|
| 60Ah | 6S3P | 18 |
| 80Ah | 6S4P | 24 |
| 120Ah | 6S6P | 36 |
| 160Ah | 6S8P | 48 |
| 200Ah | 6S10P | 60 |
These capacities are listed in our 20Ah-cell SCiB battery-bank range. The series/parallel examples explain capacity; they do not establish charging compatibility with a particular vehicle.
Read the current rating with its conditions
Evolution Lithium’s product calculations use a 12C continuous cell rating for this range. The calculation is 20Ah × 12C = 240A per cell, or 60Ah × 12C = 720A for an ideally shared 60Ah bank. That is a cell-rating calculation, not a guaranteed continuous rating for every completed installation.
The allowable current also depends on cell condition and temperature, busbars, connections, cable, fuses and the bank’s specified limits. The product’s 30C burst designation must not be treated as a continuous rating; confirm the permitted pulse duration and conditions before using it for system design.
What current sharing changes
At an illustrative 600A bank load, three parallel cells in each series group would ideally carry 200A each: 10C for a 20Ah cell. Six parallel cells would carry 100A each: 5C. More parallel capacity reduces the load on each cell when the total bank current stays the same.
Actual sharing depends on matched cells and balanced, low-resistance connections. This example explains the maths; it is not an instruction to apply a 600A test load.
There is no universal rule that doubling capacity makes a 20Ah-cell bank equivalent to a smaller-cell bank. Compare capacity multiplied by the applicable continuous C-rate, then check voltage, usable energy and the finished bank’s limits. Compare burst capability separately.
Capacity does not replace alternator output
Extra amp-hours provide more reserve for a given current deficit. They do not remove that deficit. If the audio system and vehicle together draw more than the alternator supplies, stored energy continues to fall, however large the bank is.
For longer demos, measure charging output at the engine speed you actually use and record voltage at the bank and amplifier under load. The product page’s amplifier-support table uses 14.8V and 80% Class D efficiency. Its figures are estimates of electrical support, not promises of amplifier output or listening duration.
Confirm the exact cell and charging setup
A capacity label alone does not establish cell voltage limits, internal resistance or service life. Use the exact cell identification and the supplied bank instructions. Toshiba’s high-energy cell specifications give manufacturer data with stated test conditions; those cell figures are not a vehicle installation approval.
Do not assume that a 6S bank can be directly paralleled with the existing starting battery or charged by any factory alternator. Confirm the bank’s charging range, vehicle compatibility and amplifier voltage limit before connection. An active balancer helps manage cell-group voltage differences; it does not set the alternator’s charging voltage.
What to provide when choosing a bank
- Amplifier RMS ratings, intended speaker impedance and measured current if available.
- Alternator output at idle and cruising speed, plus the measured charging voltage.
- Whether listening is mainly engine-running, engine-off or extended demo use.
- Available boot or rear-cabin space, cable route and the existing starting-battery arrangement.
Mount the lithium bank securely in the boot or rear cabin, never under the bonnet. Protect terminals and use cable and fusing rated for the installation. For the connection sequence, use the two-battery wiring guide. Send your build details through the contact form to discuss a suitable bank.
Ready to size a 20Ah SCiB LTO bank for your car audio system? Review the 20Ah SCiB LTO battery-bank options for high-current car audio, then send your amplifier RMS, alternator output, charging voltage and installation location through the Evolution Lithium configuration contact form for a practical recommendation.
