Generator/electrical question

[Mito Man]

I have a lithium battery generator which is primarily charged off a solar panel, however I brought an old petrol generator to keep alongside just for the odd times when the solar can’t keep up and I need to top up the battery.

However, said battery does not like charging from the generator, it will charge for a second then stops. Looking a bit further online it seems like lithium’s are quite sensitive and like clean noise free electricity?!
Will a pure sine wave generator work with that or do I need something else?
What wave is the electricity at home?

[Jobbo]

You get a fairly clean sine wave at home - it’s proper AC from the power station, not a generated wave from DC.

Does the lithium battery need a minimum current before it’ll charge?

[Mito Man]

Can’t find anything stating a minimum current in the instructions.

Might have to join a generator forum to ask

[Nefarious]

The problem might be to do with the "smartness" of the lithium charger, rather than the lithium battery itself. Lithium batteries in many ways are simpler to charge than lead acid ones - maximum charge all the way to full then stop, as opposed to repeated charge and discharge cycles up to 90% then trickle up to 100%.

I suspect the problem is to do with the interaction between the lithium charger, which is deciding on a current based on the state of charge of the battery, and the generator, which is variably delivering current based on demand.

If you have a simple, non-"smart" old skool battery charger, it might be worth giving that a try.

[Mito Man]

I don’t have one of those old chargers. The battery does come with a 12 volt lead to charge via a car cigarette socket but at just over 100 watts leaving the car to idle for hours isn’t really feasible.

The weird thing is it has both a DC and AC charging circuit. The DC is for charging with 12v or by 60v solar and the AC is mains voltage (just via a kettle lead, no transformer).

Further reading online I found one review stating that the AC input goes direct into the inverter which is maybe why it’s having a problem?
I know that the AC inverter outputs pure sine wave as it states that so maybe it can only accept pure sine wave when charging?

[Mito Man]

Well a week and a new generator later...

It works. Guess the battery didn’t like pauper spec electricity after all. New generator is cool, it actually has a pressurised fuel tank like range extended cars so the fuel won’t go stale, then you manually open the vent when you want to use it. Overall it’s a better system than the BMW i3 which would always fail requiring you to remove the door jamb and dig around for the manual release