As we discussed in The ARES interface (HUD), the VOLTAGE and LOAD meters on the ARES HUD report your current power level and how fast your battery is being drained, respectively.

Power in the battery is measured in Joules (abbreviated J).

Power usage is measured in Watts, which is equivalent to Joules per second (abbreviated W or J/sec).

The power usage of ARES changes depending on what you're doing. Walking, running, and flying all have associated energy costs.

Normal usage: When idle, ARES typically uses around 700 W. Walking needs another 200, for 900 W total. Batteries are sold in different sizes depending on how long they can meet the demands of "typical" usage when brand new. A typical "two-hour" alkaline battery stores 5 800 000 Joules, or 5.8 megajoules. Thus the alkaline battery will last approximately 8286 seconds, or 2 hours and 18 minutes if you spend the whole time idle, but only 1 hour and 47 minutes if you spend that time walking in circles.

Do I have to use the power system?

Yes.

It's true that keeping an eye on your battery level can be intimidating at first, but the chance of you actually getting stranded is very low. ARES auto powers off at 5% to protect you from accidents while AFK. If you have to run out to the store or something and forget you've left SL running, you'll return to a powered-off state, but you can simply boot back up and get to a charger. You'll also receive audible and on-screen warning messages at 50%, 20%, and 10% to encourage you to develop a sense of how things are going.

Additionally, many social hubs for NS units have wireless chargers in the area. These are nodes that constantly send out pulses of power to everyone within a 10–20 m radius to keep units running. Many customers enjoy keeping their NS units 'tethered' to these safe areas by giving them extremely small batteries.

I am stranded. What do I do?

If you do get stranded, try the following:

1. If you have a friend nearby who is also an NS unit, they can donate a few kJ of power to you by sending the @zap command in local chat. This will be enough so you can boot up and get to safety.
2. (Not yet available in Beta 1) By default, the distress beacon feature is enabled. If you have an owner, they will also be alerted to your plight as soon as you shut down without power. A well-prepared owner can bring you another battery, a unit to @zap you, or a wireless charger to help get you back on your feet.
3. (Not yet organized as of Dec 2023) An official Field Robotics Group repair technician can be summoned. These are trained volunteers who reside at Eisa and take pleasure in assisting stranded units.
4. Ultimately, unless you've locked the safety bolts on ARES, you can just take it off, hurry to safety, and then try again.

Recharging

Chargers come in many shapes and sizes, including floor pads, chairs, power outlets, and wireless power emitters. You can also use repair stations and diagnostics tables (repair beds) to recharge. Having some sort of charger available to you is an essential part of being a robot.

Charging instructions

To charge with a wall outlet: Stand close to the outlet and touch it. You must be within 1.5 m or the cable will disconnect. The outlet will automatically disconnect when you are full.

To charge with a charging pad: Sit on the charging pad. If a holographic screen or other menu appears, choose the top option. When charging is complete, you may need to touch another option (disconnect) to leave.

To charge with a repair station (ARC): Sit on the repair station. It will automatically identify your power and repair requirements, and eject you when the process is finished.

To charge with a repair booth (ExARC): Sit inside the booth. The screen is located on the left side. Choose the first option to begin charging, and the last option to disconnect when finished.

To charge with a diagnostics table (repair bed): Sit on the table. Choose the first (top-left) option to begin maintenance, and the last (bottom-right) to disconnect. Some tables will not charge you unless you are below 90% of your current maximum battery capacity.

To charge with a booth or display case: Sit in the booth. It will slowly charge you over time, whether you need it or not.

To charge with a wireless charging node (WCN): Stand near the charger. WCN/2 chargers (with the ball on top) can be told to disconnect by typing /5stop, and to reconnect with /5start. Other wireless chargers, such as the WCN/3, work silently and cannot be interrupted.

While you are charging, the LOAD gauge on the HUD will change colors, indicating that the current net power usage is now a negative number. Most chargers only send power every few seconds, so it is normal for this to pulse or flash rather than remaining steady.

Degrading and non-degrading batteries

Some batteries are "entropy neutral," which means they can always be recharged fully and will never lose capacity. Metabolic and Sonofusion batteries (sold as 8 hour and 24 hour, respectively) fall into this category.

Most other batteries do degrade over time. They lose a tiny fraction of their maximum storage capacity whenever power is put back into them (e.g., during charging.) Recharge them slowly to maximize the longevity of the cell.

Batteries never lose more than 60% of their original capacity due to degradation. A worn-out 48-hour (uRTG) battery will still last around 20-22 hours.

Restoring the capacity of degraded batteries

Checking Battery Health: Click the battery icon at the right-hand side of your screen to open the battery device menu (or, equivalently, access devices... > battery from the main menu). Then, choose status from the battery menu. Typical results for a brand new battery look like this:

For a degraded battery, you will see that the capacity has fallen: Current capacity: 5770993 J

And once it's more than 1% degraded, the original capacity will be shown in brackets: Current capacity: 5720407 J (originally 5800000 J)

Battery Reconditioning: Worn-out batteries can be restored to mint condition using a diagnostics table, such as the VectorLogix or Arachne X8. (These are also called repair beds.) The whole process takes less than a minute. The instructions are the same as for charging with a diagnostics table (above), but look for a button that says "repair battery" or "recondition battery" instead.

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