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When I bought my Bolt I knew I wanted the convenience of charging at home. The twist: my house has 100-amp service, and there’s a persistent internet myth that you must upgrade to 200-amp service to add a Level-2 charger. That isn’t true for the Bolt — with the right approach, 100-amp service is more than enough.
Disclaimer: I’m not an electrician — just an EV owner sharing my personal experience. Electrical work can be dangerous if done incorrectly. Always consult a qualified, licensed electrician before starting any electrical project. You are responsible for ensuring your work meets local building codes and safety requirements. I am not liable for any damages, injuries, or issues that may arise from attempting to replicate anything described here.
After reading reviews and comparing features I went with the Emporia Classic. It hit the balance I wanted: not the cheapest, not the fanciest, but solid. The biggest benefit is that it's compatible with National Grid's off-peak program and can automatically schedule charging based on off peak hours. It charges reliably, has Wi-Fi and an app for scheduling and monitoring, and it offers both a plug (NEMA 14-50) option and a hardwire whip. Since my install was outdoors and I wanted a clean look, I chose the hardwire route.
Installation was straightforward because I had a lucky break: an abandoned hose spigot right above my electrical panel. I removed the spigot, mounted a single-gang outdoor electrical box, ran flexible conduit through the old hole, and pulled the properly sized wire to the panel. The Emporia hardware uses a ¾" threaded PVC conduit fitting which made connecting to the outdoor box easy and neat.
Why you don’t need 200A just to run a Bolt
A lot of people assume you need a 200-amp service for Level-2 charging — but the Chevy Bolt’s onboard AC charger limits it to roughly 32 amps (about 7.2–7.7 kW) on Level-2, so you don’t need a huge circuit to get useful charge overnight.
That was handy for me: I installed a 40-amp breaker for the charger circuit (a common choice), but I configured the Emporia to behave as if it were on a 30-amp circuit. In practice that gives me a safe buffer so the EV and the charger never try to pull the full 40A, while still topping the car overnight easily.
National Grid off-peak (what I enrolled in)
If you’re in Massachusetts and served by National Grid, they run an off-peak EV program that pays rebates for charging during designated off-peak hours. The program currently offers $0.05/kWh for off-peak charging in summer months (June 1–Sept 30) and $0.03/kWh in non-summer months (Oct 1–May 31). There’s also a one-time enrollment incentive in some rollouts. Charging must occur within Massachusetts and you generally enroll through the program portal or partner app. (Check National Grid for eligibility and the exact program window/dates — they publish full details).
A couple practical notes: confirm the exact off-peak hours for your account (they’re published by National Grid and can vary by program/version), enroll so your off-peak charging shows up in the program’s tracking tools, and set your charger schedule to charge during those windows for the rebate.
Charging math (so you can see the real overnight numbers)
Assumptions I used (conservative & realistic):
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2020-era Bolt usable battery capacity: ~60 kWh is a common conservative usable figure for many 2020 Bolts (some later replacements/upgrades push to ~66 kWh).
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Starting state of charge (SoC) for this example: 50%, so you need to add ~30 kWh to get to 100%.
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Charger/vehicle losses: account for ~10% charging overhead (heat/inefficiencies). I show results both without and with that 10% loss so you can see both ideal and realistic cases.
Power from a 240V circuit = 240 V × amps ÷ 1000 = kW.
So:
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20 A → 240 × 20 / 1000 = 4.8 kW
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30 A → 240 × 30 / 1000 = 7.2 kW
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32 A → 240 × 32 / 1000 = 7.68 kW (Bolt is limited to ~7.2–7.7 kW by its onboard charger).
HOURS to add 30 kWh (ideal, no losses)
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20 A (4.8 kW): 30 ÷ 4.8 = 6.25 hours
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30 A (7.2 kW): 30 ÷ 7.2 = 4.17 hours
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32 A (7.68 kW): 30 ÷ 7.68 = 3.91 hours
HOURS to add 30 kWh with ~10% charging losses (realistic)
If we assume ~10% loss, you actually need about 33.3 kWh input (30 ÷ 0.9):
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20 A (4.8 kW): 33.33 ÷ 4.8 ≈ 6.94 hours
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30 A (7.2 kW): 33.33 ÷ 7.2 ≈ 4.63 hours
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32 A (7.68 kW): 33.33 ÷ 7.68 ≈ 4.34 hours
Bottom line: even at the conservative 20-amp rate you’ll get a full 50%->100% overnight in under 7 hours (with losses). At 30A and 32A you’re easily done in a single overnight window (4–5 hours). That’s why the Bolt on a properly configured 30–32A L2 circuit is more than enough for daily commuting.
Practical tips from my install
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If your charger supports setting a max breaker/amps (like the Emporia), set the charger lower than the breaker to keep a safety buffer. I used a 40A breaker and set the charger to run as if it were on 30A.
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Schedule charging during off-peak hours (National Grid) to capture rebates and lower per-kWh cost — the program’s tracking and rebate make this worthwhile.
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If you’re unsure about fitting conduit/wiring or local code, hire a licensed electrician. That money is well spent for a clean, safe install.
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Double-check connector and box sizes (Emporia uses a ¾" threaded PVC conduit fitting for the outdoor box on the unit I used) so your outdoor run is watertight and neat.
Special Note for Older Panels
If you have an older electrical panel (like mine — house built in the 1920s, breakers added in the 1980s), you may notice there’s no separate ground bar. In many older setups, the neutral bus bar is bonded to the panel enclosure, which means it also serves as the grounding point for branch circuits.In this case, the equipment ground conductor from your charger would terminate on the neutral/ground bus. This is code-compliant only if your panel is wired as a main service disconnect and the neutral and ground are bonded there. Sub-panels should have separate neutral and ground bars.
If you’re not sure about your setup, have an electrician confirm — it’s important to ensure the bond exists and the panel is up to code for safety.
Final thought
If you’re on 100-amp service and thinking “I should just upgrade the main panel so I don’t worry” — you probably don’t need to. With a 30–32A Level-2 circuit and a charger that lets you limit amperage, you’ll get all the overnight charge you need for a Bolt without the expense and hassle of a 200-amp upgrade. Couple that with a National Grid off-peak schedule and you’re charging cheaply and cleanly while avoiding a big electrical upgrade.
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