Charging ebike from solar panel direct

[Metamorfosis]

It has occurred to me how inefficient it is charging an ebike from a solar supplied 12v battery bank through an inverter to 240v and then back down to 48v through a dedicated charger.
No personal experience but I have read the victron chargers via Bluetooth app have dozens of settings. Are they capable of taking the power from a 24v panel and outputting it at 48v so you could connect direct to the ebike battery at correct ampage?
Or is this a silly idea?

 

[Googlebot]

In a word, no.

It could wreck a very expensive battery and charger.

It might be possible in the right light but a cloud comes across and the voltage drops, sun comes out and you fry the battery.

 

[DBK]

It has occurred to me how inefficient it is charging an ebike from a solar supplied 12v battery bank through an inverter to 240v and then back down to 48v through a dedicated charger.
No personal experience but I have read the victron chargers via Bluetooth app have dozens of settings. Are they capable of taking the power from a 24v panel and outputting it at 48v so you could connect direct to the ebike battery at correct ampage?
Or is this a silly idea?

Yes you could do it I think. Some of the Victron controllers can output at 12, 24 or 48 volts. If you also selected a lithium profile it should work.

However, I strongly advise you contact Victron by email first - they speak English - to see what they say.

If it can be done I would suggest you fit a dedicated charger just for the bike with a changeover switch to swap the panels from bike charging to MH charging. Putting 48 volts through the MH would be somewhat sub-optimal.

 

[Googlebot]

In a word, no.

It could wreck a very expensive battery and charger.

It might be possible in the right light but a cloud comes across and the voltage drops, sun comes out and you fry the battery.

Actually, after reading DBK’s post, I might be talking piffle!

I suppose you would need the right connectors though.

 

[Metamorfosis]

The idea came to me as I was considering having two 12v panels in series anyway so thought they bang out 40v peak like that so not that far from the 48v needed for the ebike lithium. Obviously a changeover switch as you suggest with a custom charge profile when on the 48v ebike lithium side and standard AGM for the hab side

I have votronic but I don't think it is programmable like the victron.

Look what I just found from the infamous Andy Kirby

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[Raul]

It can be done, to avoid the double conversion. I have suggested it in the past. The way to do it is to use a DC-DC buck boost converter. Such device are popular and victron does quite few of them, Orion.
In your case will be a boost dc-dc converter 12v to 48v. It Feeds from your habitation battery to your ebike pack. No other charger needed. You can fit a switch to Orion terminals and turn it on as needed. Once on, you need a multimeter to set the output. There is a potentiometer that adjusts output. Your 48v pack absorbs at 57,5v; you can set a conservative 54,4-54,6v and will charge to 95-98%SOC. Given enough time it can actually charge to 100% SOC.
I use one in the van, from alternator to habitation LFP, set at 13,65v output with a switch after the voltage ignition sensing. This gives me the ability to switch of when driving, and no charge is needed.
Another one I use in my off grid house. It feeds the alarm, internet router and camera at 12v, of the house battery pack of 48v. I have full control over the installation anywhere I have network on the phone, and the ability to switch the inverter of, without cutting the power to the router, alarm etc.
look for a victron Orion 12/48 , either isolated or non isolated, on the victron energy site. Pull the documentation and convince yourself.

 

[Metamorfosis]

Thanks Raul. You are still converting from 40v down to 12v battery bank and then backup to 48v. I think if I was going to go to the trouble of setting something up I would want the direct option to avoid cycling the leisure batteries. My last bike had an 840w battery so after inefficiencies of an inverter and then dedicated bike charger its possible it could empty a single varta 95ah AGM if charged from flat and no solar going in.

 

[rosalan]

What a faff. Buy a cheap inverter. Job done. We hve two electric bikes and my cheap none "pure" unit has both bikes fully charged before my G and T glass is empty.

 

[Metamorfosis]

You are of course right rosalan. Just an exercise of the mind if it's possible which it appears it is.

 

[Raul]

What’s the faff? You convert 12 to 240v then 240 to 48v. Double conversion and a 1/4 wasted if not more.
Orion takes it from 12 to 48 dc to dc straight. One device, more efficient and cheaper. But I understand your point, stick with what you are comfortable with.

76zedfour
You miss understood. I never said 40 to 12 and then back to 48.
If you look at the spec of the converters, they are wide input. A 12/48 converter will take anything from 8 to 15-17 and convert it to 48. That’s a 12/48 model. There are lots of other models 12/12, 12/24; 12/48;;; 48/12,24/12 etc.

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[Gaston aires]

I’m with rosalan on this one. Cheapo inverter way to go.
Phil

 

[eddie]

Yes anything is possible.

With my set up I am normally on inverter or mains so charging our bike is not an issue, and protects the batteries which is the biggest concern