Charging with a y

[HughMorris]

I've bought an inverter suitcase generator to charge my ebike batteries off grid. To save time can I charge two batteries at the same time with a 'Y' splitter?

 

[Andy-Mat]

I've bought an inverter suitcase generator to charge my ebike batteries off grid. To save time can I charge two batteries at the same time with a 'Y' splitter?

It depends upon where the 'Y' splitter is going to be fitted,( hopefully in the mains side if it is a 240 volt inverter, not in any DC side), how much current the inverter can supply and how much power the charger(s) use.
Never connect two batteries together, as the possible varying charge levels can become quite "explosive"....A BMS for ONLY two separate batteries (not the same type as is IN a normal Li-ion Battery!), assuming both batteries are the same nominal voltage of course, is a must for safety.
More detail is needed.
Andy

 

[Ocsid]

It could also depend on the waveform quality of the inverter generator, whether even using one or other charger would work.
Some have very rudimentary modified sine waves, that not all chargers can cope with.
Does yours work successfully with each charger separately?
If so, then a two way or more extension lead for the mains outlet is all that is required, assuming the generator's capacity is adequate.
Whatever, don't risk seeing if the chargers survive the generator running out of fuel, don't ask how I know.

 

[Deleted member 33385]

don't risk seeing if the chargers survive the generator running out of fuel, don't ask how I know.

How do you know? (Sorry if answering this question causes you to recall traumatic memories of any sort) - What sort of damage does a generator running out of fuel do to a charger, while it's charging a battery? And is it terminal for the charger and/or battery?

 

[Ocsid]

In my case terminal to a CTEK 3600 charger, charging a LA battery, some years back. The engine surges as the last few drops of fuel run out.

I also know of two cases, where generators running out of fuel have written off LA battery chargers employed in caravans.

 

[HughMorris]

Thanks for your early replies fellas. Great forum this. I've decided to play safe and charge one battery at a time.

 

[Ocsid]

Thanks for your early replies fellas. Great forum this. I've decided to play safe and charge one battery at a time.

For clarity, can I say any concern is not charging two at a time, it's the "quality" of the waveform some inverter technology generators produce for powering a "sensitive" charger.

 

[Deleted member 33385]

In my case terminal to a CTEK 3600 charger, charging a LA battery, some years back. The engine surges as the last few drops of fuel run out.

I also know of two cases, where generators running out of fuel have written off LA battery chargers employed in caravans.

That's very good to know! I think I'd better get some high quality surge protectors to test out on my generator at low fuel... The generator is "Pure sine wave" but that could of course change, when it's about to splutter out.

 

[WheezyRider]

Just wire the input cables of the the two chargers together in parallel, or just use a multi-way plug adaptor.

If you are worried about voltage surges when running out of fuel you can put an extra varistor across the input to the charger. Most switched mode power supplies will have one already, but probably wouldn't hurt to add one:

Varistor - Wikipedia

en.wikipedia.org

I don't think it should matter too much about the generator output waveform, so long as it doesn't have any nasty spikes. It is rectified to DC in the input side of the charger switched mode power supply, before being inverted to high frequency AC, which is then used to create the output voltage.