Charging an Ebike with solar question?

[AreWeLostYet]

One of the things we don't know about this 'roll-your-own' solution:

Does the lithium battery on the bike in question have a built-in BMS or not?

Some do, and only need a 2 pin connector (normally) to supply the required voltage and current. Sometimes there is a third pin for voltage or temperature sensing.

Those are what are referred to as 'smart batteries'.

Others have external controls built-in to the 'smart charger'...they will have multiple pins on the battery connector.

Considering building an e-bike led me to research a good many power packs. I never saw a lithium power pack for an e- bike that did not advertise having it's own battery management system (BMS). They are standard. No company wants to be left open to lawsuits from someone's lithium battery pack going up in flames in their garage and burning their house down. Almost all e-bikes, and a lot of other electric vehicles like power chairs, scooters etc. use that same plug and I'm confidant, the same pin-outs. 

One thing you can say about Chinese manufacturers. They start using something that sells and they stick with that standard. Started back when they were bootlegging PCs and Windows software. Ads all included "PC compatible", "MS-DOS compatible", "Windows compatible". Never mind most of the OS and app software was pirated. And half the motherboards, RAM and CPUs, were purchased through their back door, having been stolen by Chinese and Vietnamese gangs in Orange county or the 60 freeway corridor in So Cal.

There seems to be a tendency in some of these threads to overly complicate things. Probably to establish "expert" dominance by discrediting the obvious, simple and affordable solution.

 

[tx2sturgis]

Hey if it is obvious, simple and affordable, I'm all for it. 

Many of our members ask questions like this, and do so because they might have limited knowledge of the concepts, connectors used, charging requirements, etc.

The car charger you linked is shown with a 3-pin XLR style connector. 

Is that connector, and the voltages it uses, standardized on all (or most) e-bikes? Or is there an adapter that can be used on other batteries? I simply dont know. 

I DO know that at least one e-bike manufacturer uses a proprietary charger and will not sell you one without your invoice number from when you bought the e-bike. This is a 'theft-deterrent' of sorts. 

In my experience, most manufacturers have propriety standards and connectors,  unless an industry standard prevails in the market. 

But if it is a universal standard, then the OP might want to make use of it. 

And I will have learned something new!

Since you have researched this topic more than I have, did you find any public charging stations that can accommodate e-bikes? I'm curious about that one.

 

[QinReno]

Hey if it is obvious, simple and affordable, I'm all for it. 

I'm with you, Mr Pirate Man. Somehow I don't think that an $804 charger qualifies. What does qualify is to plug the charger that comes with the ebike into a 120 VAC inverter that most of us will **already** have in our rigs. Cathy's charger draws 120W, and no doubt most of us have inverters that can handle that. So, extra cost = $0. Simple and obvious? Just plug in. DUH. Even a injinier like me could figure that one out.

And would I ever want to have to wire up my own cable to interface a DC-DC converter to the battery - not hardly.

 

[AreWeLostYet]

Hey if it is obvious, simple and affordable, I'm all for it. 

Many of our members ask questions like this, and do so because they might have limited knowledge of the concepts, connectors used, charging requirements, etc.

The car charger you linked is shown with a 3-pin XLR style connector. 

Is that connector, and the voltages it uses, standardized on all (or most) e-bikes? Or is there an adapter that can be used on other batteries? I simply dont know. 

I DO know that at least one e-bike manufacturer uses a proprietary charger and will not sell you one without your invoice number from when you bought the e-bike. This is a 'theft-deterrent' of sorts. 

In my experience, most manufacturers have propriety standards and connectors,  unless an industry standard prevails in the market. 

But if it is a universal standard, then the OP might want to make use of it. 

And I will have learned something new!

Since you have researched this topic more than I have, did you find any public charging stations that can accommodate e-bikes? I'm curious about that one.

I find it's more useful to refer someone seeking help to something they can buy off the shelf instead of getting out the scientific calculator and befuddling them with kludging together components they don't even know names for.

The emerging standard, which the bike I linked to uses - as do almost all ebikes, uses the EnergyBus connector which may appears 3-conductor at first glance is actually 6 conductor.

The proof of purchase of the item to use the power supply is not 'theft-deterrent'. It's to assure the charger is not used on something it's not compatible with, thus trashing the power supply or device it's plugged into and then the user filing for refund or a law suit for ruining the power supply or the (incompatible) device. Thieves would have no trouble cobbling together a power supply for any ebike.

There are charging stations all over Europe. Probably cities in the US near universities and large business districts. Don't know, but with Europe leading, there is bound to be bleed-over into use in the US as well.

 

[AreWeLostYet]

I'm with you, Mr Pirate Man. Somehow I don't think that an $804 charger qualifies. What does qualify is to plug the charger that comes with the ebike into a 120 VAC inverter that most of us will **already** have in our rigs. Cathy's charger draws 120W, and no doubt most of us have inverters that can handle that. So, extra cost = $0. Simple and obvious? Just plug in. DUH. Even a injinier like me could figure that one out.

And would I ever want to have to wire up my own cable to interface a DC-DC converter to the battery - not hardly.

Simply showing that 12vdc - 48vdc consumer converters do exist.

 

[tx2sturgis]

The proof of purchase of the item to use the power supply is not 'theft-deterrent'. It's to assure the charger is not used on something it's not compatible with, thus trashing the power supply or device it's plugged into and then the user filing for refund or a law suit for ruining the power supply or the (incompatible) device. Thieves would have no trouble cobbling together a power supply for any ebike.

If you read this page, and interpret it differently that I do, that's fine. I take it to mean they are wanting only LEGAL owners of the bike to be able to order replacement chargers. 

https://www.radpowerbikes.com/collections/accessories-and-replacement-parts/products/radmini-charger

Liabilities and lawsuits for the bike itself, compared to the charger, would be much greater, one would think.

 

[tx2sturgis]

I'm with you, Mr Pirate Man. Somehow I don't think that an $804 charger qualifies. What does qualify is to plug the charger that comes with the ebike into a 120 VAC inverter that most of us will **already** have in our rigs. Cathy's charger draws 120W, and no doubt most of us have inverters that can handle that. So, extra cost = $0. Simple and obvious? Just plug in. DUH. Even a injinier like me could figure that one out.

And would I ever want to have to wire up my own cable to interface a DC-DC converter to the battery - not hardly.

Well, again, my original answer was to use an off-the-shelf sine wave inverter and make it SUPER easy, but others posted some alternative, untested, and un-supported solutions.

 

[QinReno]

If you read this page, and interpret it differently that I do, that's fine. I take it to mean they are wanting only LEGAL owners of the bike to be able to order replacement chargers. 

https://www.radpowerbikes.com/collections/accessories-and-replacement-parts/products/radmini-charger

Liabilities and lawsuits for the bike itself, compared to the charger, would be much greater, one would think.

They write an interesting comment on that page (below). I suspect what is going on here is exactly as you say, liability and possible lawsuits. 

E-bikes with 750W motors and large lithium battery packs are right on the ragged edge of the sort of liability exposure that most "small" companies would want. Some people will crash and end up in the hospital. Some will likely get run over by cars. If some fool jury-rigs the battery and it burns up or possibly explodes, that fool will shirley swear on a 1000 bibles that he did "everything" correctly and above board, so who gets the blame. One guess.

Plus of course, they don't want the same fool buying their 48V battery and jury-rigging on another ebike that's meant to take only a 36V battery in order to soup it up by doubling the power. Just a couple of scenarios. 
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"[size=large][font=arial, sans-serif]In order to buy a [font=arial, sans-serif]charger[font=arial, sans-serif] from Rad Power Bikes you will need to confirm legal ownership of the bike, basic requirements for this would be providing your name and order number.[/font][/font][/size][/font]

[size=large][font=arial, sans-serif]Buying a charger for a bike you purchased second hand? You will need to provide the name and order number from the original order."[/size][/font]

[font=arial, sans-serif] [/font]

 

[tripper]

The chargers depend on who you got the battery from, my current batteries use 5.5x2.1mm DC Power Cable Jack, a different ebike I had used a proprietary 3 pin jack.

I do have the stock 3 amp only charger and a second variable charger which I really like.

The variable charger will let me set it to charge the battery anywhere from 80% to 100% full charge (use 80% to give the battery a longer total life) and also lets me adjust the charging rate from 1 amp to 5 amps AC input (120watts to 600 watts); this is nice as I can slow charge the battery when I do not have enough reserve solar, or max charge it when I have plenty or am in a hurry.

 

[tx2sturgis]

Cool info Itripper, no thanks button or I woulda mashed that!

 

[crofter]

Looks like the folding model gets quite small. ~ crofter

• Folds from 60″ x 23″ x 45″ to a compact 33″ x 18″ x 32″

 

[DiANA R]

I charge my 48V ebike battery using a simple 300W modified sine wave inverter.  The key is the actual charger that you use for your ebike battery.  Mine came with a 2A charger that states it requires 120 watts.  This works fine for recharging.

Hi KathyC, my bike charger is 54.6 V - 2A with a 500 W engine. So the answers took me to the charger-and MrAlvinDude helped me figuring out the charger requires about 109.2 W. I think that I can get a 200-300 W inverter to charge it in about 4.6 hours. Make sense to you?

 

[DiANA R]

Looks like the folding model gets quite small. ~ crofter

• Folds from 60″ x 23″ x 45″ to a compact 33″ x 18″ x 32″

Not quite as compact as I would like but I love it-it is about 55 lbs. It's about the size of a big dog, Diana

 

[DiANA R]

If you want a definitive answer, you need to know a lot more information first:

1. is the actual charging electronics inside the battery unit on the bike, or in external electronics? (and don't assume you know the answer ahead of time).

2. Kathy's unit says 2A and 120W. That would indicate it gives a 60V DC output, which would charge the 8.8AH battery up in somewhat more than 4 1/2 hours.

3. it's unlikely that her unit gives a 12V output at 2A, and there is a boost circuit inside the battery box, as it would take 4X to 5X as long, or 18-22 hours, to recharge the battery. 

You need to know all of the parameters first, and not simply assume them. Then you can figure what you're doing.

EDIT: a couple of extra items:

4. it would make sense to actually have the charging electronics, per se, inside the battery box, as then the electronics can more easily perform "balanced charging", meaning all the different cells in the battery are monitored during the charging process, and balanced evenly.

5. OTOH, the complete charging circuitry could be in the external box, but then it would need a multiconductor cable to plug into the battery, so that once again all cells could be monitored and charged evenly.