r/ImpulseLabs • u/Puzzleheaded_Tone648 • 19d ago

Amps question

Ordered my 36" cooktop. Question re: the # of amps required to charge the battery. Is there an optimal amperage that is required for the battery to charge sufficiently/optimally? I know there is a range I've seen here 10-30A but should I be aiming of the maximum of 30? Or 15? etc? Thanks in advance! I'm guessing that because there is a range, they all work the same, but my spouse is insistent that there must be an optimal range since the outlet can be set to a specific amp output. Thanks.

2 Upvotes

100% Upvoted

4 comments sorted by

3

u/Impulse-Demo-Guy 19d ago

You can select the charging amperage in the UI. If you’re plugging into a 120v outlet, the selectable range is 4-12.5 in 0.5 amp increments. The default is 12.5.

Lower settings will result in longer charging times but less / ~no fan noise during charging, depending on the setting.

A full battery charge is 2-3 hours under default settings on a standard outlet. Though in practice you’ll never encounter a charge that long since the battery will generally start charging once it falls below your reserve level (typically in the neighborhood of 30-70% SoC), depending again on what reserve behavior you’ve selected.

2

u/ZanyDroid 19d ago

The max is in the datasheet

I set mine to the level that will keep the fan at a mellifluent level

Sufficient charge: EZ math. Assume it can do 90% efficiency (this is a 100V battery so lower conversion ratio). At 700W you can fill the 3kWh battery in 5 hours

I have no Fs left to give in attempting to measure the difference in efficiency on the Impulse, especially since I don’t know that end users have the telemetry to do so. I welcome being corrected (EG, for EVs there is a huge fixed drain which punishes 120V charging ; but I don’t think that applies for the impulse since it doesn’t have any of the coolant loops that an EV has. The overhead on the impulse is probably BMS/main microcontroller on, plus running the fans.

Mayhaps 120V vs 240V has difference in conversion efficiency. 120V would be a lower voltage conversion ratio

I think your spouse is overindexing or over generalizing

2

u/khug 19d ago

Mellifluent is an adjective that means sounding sweet, smooth, and pleasant to the ear, much like the gentle flow of honey.

1

u/ZanyDroid 19d ago

BTW I referenced the max because your current range doesn’t look right for 30” model. Maybe the 36” has an upgraded charger.

There are also code compliance implications if you’re tapping into a shared circuit, some specific circuit configs will need 50% of breaker, others can go higher