Heavy add-onsHIDs/light bars, winch, air suspension, etc.
How many separate power wire runs?
Most builds run one cable. Big systems sometimes run two or more smaller cables in parallel instead of one huge one, that changes the total capacity.
1 run
2 runs
3+ runs
What gauge is each run?
If you're running more than one cable in parallel, tell us the gauge of ONE of them, not the combined size. Pick what's actually installed, not what you think it should be.
Not installed yet
8 AWG or smaller
6 AWG
4 AWG
2 AWG
1 AWG
1/0 AWG
2/0 AWG
3/0 AWG
4/0 AWG or bigger
How long is each run?
Battery to amp rack, one direction. If you're running multiple cables, this is the length of one of them (they're normally the same length). Longer runs need thicker wire to carry the same current without losing voltage along the way.
FEET, ONE WAY, PER RUN
OFC or CCA wire?
Copper clad aluminum (CCA) is cheaper but carries less current per gauge size than pure copper (OFC). Check the packaging if you're not sure.
OFC (oxygen free copper)Pure copper, best conductor
CCA (copper clad aluminum)Common in budget kits
Not sureWe'll assume CCA to stay on the safe side
Is a high-output alternator even available for your vehicle?
High-output alternator makers only build for popular platforms, some vehicles have no aftermarket option at all.
YesI've found one, or my platform is commonly supported
Not sureHaven't checked yet
NoI've checked, nothing exists for my vehicle
Could your vehicle physically fit a second alternator?
Bracket kits for dual alternators only exist for a handful of platforms, mostly trucks and SUVs.
YesBracket kits exist, or there's engine bay room
Not sure
NoNo room, no kit available
Are you open to a lithium battery bank?
Lithium performs better here, but it costs meaningfully more than AGM. This is a real budget call, not just a technical one.
Yes, open to lithiumBest performance, higher cost
No strong preferenceRecommend whichever actually solves it
AGM/lead-acid onlyWant to avoid lithium's cost
Want a recovery-time estimate?
If you run repeated demos or passes, this estimates how long your system needs to recharge between them. Optional, skip if you don't do back-to-back sessions.
TYPICAL SESSION LENGTH (MIN)
REST TIME BETWEEN (MIN)
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Battery
Alternator
Amp Rack
Est. Audio Capacity- A
Est. Music Demand- A
Potential full-output demand
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Alternator
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Battery
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Wiring
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Your Cheapest Path
Recovery Estimate
Est. battery draw per session
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Est. recovery time
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Verify It In Your Vehicle
Estimates current draw from RMS wattage, amp class efficiency, and rail voltage, then compares it against your alternator's real output, either your tested idle/driving numbers if you provided them, or your rated amps scaled by a typical RPM curve if not, minus a reserve for factory loads. Multiple alternators are treated as a combined total. Music-dynamics discount reflects the crest factor of real content vs. sustained test tones. Single-alternator recommendations are rounded to realistic product classes, and vehicles with no compatible high-output alternator or no room for a second unit get a demand-reduction/idle-up plan instead of an impossible number. Battery sizing reflects your stated lithium preference; AGM figures assume ~0.5C safe continuous discharge, lithium assumes your stated (or a conservative 1C) rating. The recovery estimate assumes recharging happens at idle and is capped by your battery chemistry's safe charge-acceptance rate (lithium ~1C, AGM ~0.3C, flooded ~0.2C). Upgrade order follows standard install practice: fix grounds/wiring before spending on batteries or alternators, a cheap Big 3 upgrade resolves a real share of "electrical" complaints on its own. This is a planning guideline built from the inputs you gave it, not a lab measurement, treat it as a starting point, not a verdict.
