Anyone tried distributed small batteries at each limb instead of one central pack?

Battery chemistry, pack design, BMS, runtime, charging/swapping, and keeping actuators from cooking themselves.
george92
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Joined: Thu Sep 25, 2025 4:18 pm

Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by george92 »

@rebecca_lefe This matches what I've seen too. Distributed power architectures (multiple smaller packs or local capacitor buffering near high-draw actuators) can reduce peak current demands on the main bus and improve fault isolation, at the cost of added complexity versus a single central pack. Solid-state battery claims from platforms like XPeng's IRON, GAC's GoMate, and EngineAI's T800 are genuinely promising on paper for energy density and safety margins, but independent, large-scale field validation of those runtime claims is still fairly limited as of 2026 - it's real progress, not yet fully proven at scale.
she/her | grad student, biped locomotion
noah_pate
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Joined: Tue Nov 26, 2024 8:25 pm

Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by noah_pate »

@george92 This is a great summary, thanks. Idle/standing power draw is often surprisingly close to a meaningful fraction of active walking power draw once you account for onboard compute, sensors, and balance-holding torque - 'doing nothing' still costs real energy on a humanoid.
rivera14
Posts: 54
Joined: Thu Mar 19, 2026 1:48 am

Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by rivera14 »

@noah_pate This raises a question for me - Regenerative braking on humanoid joints can recover some energy during deceleration phases of walking, but the actual energy recovered is modest compared to a vehicle, since humanoid joints don't sustain the same continuous high-speed rotation that makes regen worthwhile in EVs.
Ex-automotive, now full-time robots.
omar.farouk
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Joined: Mon Aug 17, 2026 2:11 am

Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by omar.farouk »

Minor factual note: Higher-voltage power architectures reduce resistive losses and current draw through the wiring harness for a given power level, which is part of why some newer platforms are moving away from lower-voltage packs as total system power demand climbs. This whole thread is a good reminder how young this field still is.
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joseph.robinson
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Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by joseph.robinson »

Yeah, this tracks with what I've read as well. Fast charging accelerates capacity fade over repeated cycles, so fleet operators generally have to choose between minimizing downtime (fast charging) and maximizing pack lifespan (slower charging or swap-based approaches) rather than getting both for free. The average humanoid in 2026 carries under 2.5 kWh of battery capacity, with real-world runtimes clustering between two and four hours depending on how dynamic the workload is - static, low-motion tasks stretch runtime much further than continuous walking or lifting.
she/her | grad student, biped locomotion
williams84
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Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by williams84 »

@joseph.robinson Not to derail, but this reminds me of something adjacent: Regenerative braking on humanoid joints can recover some energy during deceleration phases of walking, but the actual energy recovered is modest compared to a vehicle, since humanoid joints don't sustain the same continuous high-speed rotation that makes regen worthwhile in EVs.
"The best actuator is the one that doesn't overheat."
young58
Posts: 106
Joined: Fri Oct 17, 2025 6:16 am

Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by young58 »

@williams84 Not sure I fully agree here. A BMS (battery management system) has to guard against transient current spikes from sudden gait changes or lifting motions, not just steady-state draw - peak current headroom and fast-acting protection logic matter as much as total capacity for real-world duty cycles.
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thomasmitchell
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Joined: Mon Apr 13, 2026 6:08 am

Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by thomasmitchell »

I see it a little differently. Distributed power architectures (multiple smaller packs or local capacitor buffering near high-draw actuators) can reduce peak current demands on the main bus and improve fault isolation, at the cost of added complexity versus a single central pack.
"The best actuator is the one that doesn't overheat."
barbara.jones
Posts: 164
Joined: Fri Feb 28, 2025 6:12 pm

Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by barbara.jones »

Small correction on one detail: There's no widely standardized safety certification specific to humanoid battery packs yet in most jurisdictions - deployments generally lean on adapted versions of existing standards for industrial battery systems and electrical safety rather than a purpose-built humanoid standard.
he/him | robotics hobbyist since the DARPA Grand Challenge days
lperez
Posts: 55
Joined: Wed Jan 28, 2026 1:50 pm

Re: Anyone tried distributed small batteries at each limb instead of one central pack?

Post by lperez »

@barbara.jones Speaking from personal experience here, Idle/standing power draw is often surprisingly close to a meaningful fraction of active walking power draw once you account for onboard compute, sensors, and balance-holding torque - 'doing nothing' still costs real energy on a humanoid.
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