charging from a 12v inverter - some details

[Mr President]

Hi All

I've wondered for a while about charging the my Whyte E160 from a car battery via an inverter. I've seen a few posts discussing, but nothing really about whether it has been successful or not, except for those who are lucky enough to have full on RV set-ups. I just wanted to be able on occasion to do a few more runs at Forest of Dean, Cwmcarn and Bike Park Wales without the expense of a spare battery. If it was a weekly thing a spare battery would make some sense, although change out on the Whyte not as straight-forward as on some others.

In the end I bought a pure sine wave inverter for 120 quid ( I think a modified sine wave model for the half the price would work as well for bike charging) and a 45 amp hour 12v gel battery.

Yesterday I rode the bike to completely flat. Then tried the inverter using the Bosch standard 4 amp charger. the 625 watt hour battery on the Bosch charged at about 20% per hour up to 60%, when the 12v battery was flat.

I can post the models I purchased if it is of interest to others.

 

[Barbara_Reed]

I do something similar, but I use a pair of 25 amp hour LiFePO4 batteries in parallel, which I charge usually from a solar panel. Shimano charger for the trike, Bosch 8 amp for the Flyer, and a 2kw continuous load pure sine wave inverter. I believe this is actually a requirement for some chargers. I can charge the pair of batteries at home, as well, of course. All from China. The whole battery set up goes in a box in the bottom of the camping trailer and the flexible panel on top. The single most expensive item was the inverter, at 120 euros then the solar controller, at about 90 euros, closely followed by the 63 euro flexible 50watt panel . The batteries were 23 euros each. I also have a 100watt folding panel but it's too heavy for touring. I can also use the. Bosch travel charger direct on 12 volts but at 2amps it's slow.

 

[Mr President]

I should have said that the inverter I bought was 600W constant output

 

[Barbara_Reed]

I calculate that's good for a 4 amp charger... Mine will run a cooker! (a small one)

 

[flash]

Hi All

I've wondered for a while about charging the my Whyte E160 from a car battery via an inverter. I've seen a few posts discussing, but nothing really about whether it has been successful or not, except for those who are lucky enough to have full on RV set-ups. I just wanted to be able on occasion to do a few more runs at Forest of Dean, Cwmcarn and Bike Park Wales without the expense of a spare battery. If it was a weekly thing a spare battery would make some sense, although change out on the Whyte not as straight-forward as on some others.

In the end I bought a pure sine wave inverter for 120 quid ( I think a modified sine wave model for the half the price would work as well for bike charging) and a 45 amp hour 12v gel battery.

Yesterday I rode the bike to completely flat. Then tried the inverter using the Bosch standard 4 amp charger. the 625 watt hour battery on the Bosch charged at about 20% per hour up to 60%, when the 12v battery was flat.

I can post the models I purchased if it is of interest to others.

Those figures sound about right. The only issue is flattening the GEL battery. They're really only designed to provide about 50% output capacity, like most other wet cell batteries. Completely discharging the battery like that will lead to an extremely short battery life. LiFePO4 batteries are happy to around 80% discharge.

I's strongly recommend you add another battery to your system, or switch to Lithium.

My *portable* charger system is a 200aH LiFePO4 battery and 2000W pure sine wave inverter. That's overkill but I sometimes have two bikes to charge. 200aH gives me about 2000wH of usable capacity or 4 x 500wH bike batteries.. I also use it for other things but I have something considerably larger in my camper.

Gordon

 

[Mr President]

Those figures sound about right. The only issue is flattening the GEL battery. They're really only designed to provide about 50% output capacity, like most other wet cell batteries. Completely discharging the battery like that will lead to an extremely short battery life. LiFePO4 batteries are happy to around 80% discharge.

I's strongly recommend you add another battery to your system, or switch to Lithium.

My *portable* charger system is a 200aH LiFePO4 battery and 2000W pure sine wave inverter. That's overkill but I sometimes have two bikes to charge. 200aH gives me about 2000wH of usable capacity or 4 x 500wH bike batteries.. I also use it for other things but I have something considerably larger in my camper.

Gordon

Thanks. I did wonder about that aspect. in reality I only plan to charge up during a lunch break, so the 50% level shouldn't typically be transgressed. Don't see my ride buddies eating pies for more than an hour. on the test run I wanted to see the limits. for my limited ambition it's already a costly solution. If I eventually move more off-grid I'll definitely look to boost the battery bank one way or another.
Where do you stand on pure sine wave versus modified sine wave if considered purely for bike charging?

 

[Mr President]

I do something similar, but I use a pair of 25 amp hour LiFePO4 batteries in parallel, which I charge usually from a solar panel. Shimano charger for the trike, Bosch 8 amp for the Flyer, and a 2kw continuous load pure sine wave inverter. I believe this is actually a requirement for some chargers. I can charge the pair of batteries at home, as well, of course. All from China. The whole battery set up goes in a box in the bottom of the camping trailer and the flexible panel on top. The single most expensive item was the inverter, at 120 euros then the solar controller, at about 90 euros, closely followed by the 63 euro flexible 50watt panel . The batteries were 23 euros each. I also have a 100watt folding panel but it's too heavy for touring. I can also use the. Bosch travel charger direct on 12 volts but at 2amps it's slow.

Merci. I'm amazed at the low cost of the batteries. Might look further into that.

 

[flash]

Thanks. I did wonder about that aspect. in reality I only plan to charge up during a lunch break, so the 50% level shouldn't typically be transgressed. Don't see my ride buddies eating pies for more than an hour. on the test run I wanted to see the limits. for my limited ambition it's already a costly solution. If I eventually move more off-grid I'll definitely look to boost the battery bank one way or another.
Where do you stand on pure sine wave versus modified sine wave if considered purely for bike charging?

Always pure sine wave. If for no other reason than these things have many other uses than charging a battery that you might explore into the future. Why limit yourself for a few dollars?

And yes, for a hour top up, your system should do fine.

Gordon

 

[Pdoz]

Yesterday I rode the bike to completely flat. Then tried the inverter using the Bosch standard 4 amp charger. the 625 watt hour battery on the Bosch charged at about 20% per hour up to 60%, when the 12v battery was flat.

Sounds like that battery is the limiting factor.

The other day I found my battery at 2 % pre ride ( doh... plug in charger ...) , I left the battery charging in my ford ranger, which comes standard with a puny 150 watt inverter. I wasn't expecting much, but after 20 minutes driving there was almost 30% charge showing on the bike!

Yes, I do know those numbers don't add up.....so either the bike is lying or the cars inverter was pumping out a lot more whatevers than it was rated at ! Makes me wonder where the magic smoke would escape if I pushed the ford rangers inverter for too long

 

[Mr President]

Sounds like that battery is the limiting factor.

The other day I found my battery at 2 % pre ride ( doh... plug in charger ...) , I left the battery charging in my ford ranger, which comes standard with a puny 150 watt inverter. I wasn't expecting much, but after 20 minutes driving there was almost 30% charge showing on the bike!

Yes, I do know those numbers don't add up.....so either the bike is lying or the cars inverter was pumping out a lot more whatevers than it was rated at ! Makes me wonder where the magic smoke would escape if I pushed the ford rangers inverter for too long

that's interesting. let us know if you can repeat the experience. Might have to buy a new car now!