Topping off battery from inverter?

Is it possible/practical to top off the battery using a vehicle inverter or portable generator with inverter? I know the inverter built into my pathfinder is no where near powerful enough, but I see 1100 and 1500 watt inverters on Amazon and small gas generators with 2000W+ inverters on them.

You can use the SP140 charger with a generator or an inverter as long as it can provide at least 1100W continuous. I’ve recently fully charged my SP140 battery on a portable generator and it worked fine.

Thanks. The website mentions “Fast-charger compatible battery (Charge up in 1 hr with aftermarket charger)”. Do you have any recommended fast-chargers?

I’m just curious if I could pair up a 4650w generator + fast charger to top off the 4kw battery in a reasonable amount of time. Say I’m with an instructor, do a few short flights, and while receiving further instruction on the ground, top the battery off before going back up.

I didn’t want to buy two batteries up front, who knows how much I will actually get around to flying and need that second battery, but I am worried about the flight time during instruction. At least a generator I can use for multiple other things beyond PPG charging.

On a side note, the charger you sell. I really wish it had a power switch on it. It arcs when plugging into an outlet.

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I did my courses with instructor together with ICE guys.
Can just tell that the 1h battery was plenty fine for me. While ICE guys warmed up their engines or had problems to tune them(run properly) or even start up(!) I was yawning or already up in the air.
Our flights were around 20-30 minues long and we could only make 2-3 flights per evening before sun went down anyway. All in all, out of 4 hours/day with the instructor, flight time was less than 1 hour, rest was talk, breake, and try to start ICE motors and manage failed takeoffs.
One guy had a broken gasket so he had to pause the flights and replace the piston as well. Second guy lost his exhaust pipe in the air due to vibrations which led to blade damage. Third could not start his motor for a few lessons. While I just double tap on the controller and fly away. At the end I was the first one to get approved in the group and could fly solo without instructor while the rest of they guys was still struggling.

This one will charge the battery at ~30A so 3x faster than the stock one

This at 45A so in one hour:

This one has even bluetooth

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Have you used any of those personally?

Buying anything from Aliexpress scares me, let alone a fast charger for a $2200 battery… I’m not looking to burn the house down :rofl:

Yeah, they are used by ebikers as they are very power dense. Less than half the size of stock charger but can put out 4x of power. These are highly reliable rectifiers that are used in telecom industry(powering 3g/4g networks) and are made to run 24/7. We are just lucky enough that people modify these so we can adjust power settings in them. Here is one spitting out 5000W/50A
There is nothing wrong with aliexpress. Just need to know what to buy and know what you are doing when charging batteries.

Just as info:

I myself use server power supplies (emerson) with 162 amperes of continuous power for very large batteries (over 12 kw/h).

with batteries like the sp 140, i see no point in using more current than a maximum of 20 amps. 1. The battery needs a rest period after use. high charging current damages the cells, especially when charging within 5 hours after use. it is not comparable to tool batteries, which are very small and only have a fraction of the mass of the sp 140 battery.

with small batteries, the cooling phase is much faster inside.

if you let a sp 140 battery cool down, it will get cold on the outside much faster than on the inside. This then causes problems when you reload with a lot of electricity.

The internal resistances of the cells are then not the same.

everything leads to faster aging of the inner cells.

therefore with tip. slow is the magic word and patient.

if you actually fly a lot better buy a 2 battery. the best long-term solution.


Agreed, but this inline switch works well and solves the arcing problem.

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Thanks, I hadn’t gotten around to looking yet, that will do. I actually have an official fast charger for my OneWheel and that too arcs when its plugged in. I don’t understand that design decision by the companies that make them. I suppose the charger for the SP140 is more industrial and could be designed to be turned on with a rack of equipment, without accidentally turning it off… but that consumer equipment like the OneWheel charger also does it seems unacceptable to me

Decision is to save money. Btw it does not arc at 230V here in Europe.