Solar charging for ebike help

Hikertrash

Member
Can you charge a 48 volt ebike battery with a solar charger?

I have a Lectric XP on order and should be getting it soon. I travel in Dodge Grand Caravan. I'm thinking of adding a narrow 90 watt solar panel (80 watt output, 4.5 amps charging power) .

If possible, besides the panel and controller, what size battery and inverter would I need to charge the battery?
 

Sierratim

Well-Known Member
Region
USA
City
Nevada City, CA & Paradise Valley, AZ
Many ebikes come with 2A chargers with 4A versions also available. This puts the charger output in the 100W to 200W range for a 48V battery pack (50+ volts at full charge). A panel with an 80W rating, running an inverter and then a 1A rated charger (50+ watt output) could work. Obviously, charge times would be longer.

An inverter in the 100W range would be a reliable choice. I'm not sure what battery size you're referring to.
 

rich c

Well-Known Member

Plus many more
 

Hikertrash

Member
Can you charge a 48 volt ebike battery with a solar charger?

I have a Lectric XP on order and should be getting it soon. I travel in Dodge Grand Caravan. I'm thinking of adding a narrow 90 watt solar panel (80 watt output, 4.5 amps charging power) .

If possible, besides the panel and controller, what size battery and inverter would I need to charge the battery?

Thanks. I didn't mean battery size but battery type (acid, lithium, etc), and maybe a link to a decent one.

Added: Here's an inverter I was thinking may work.

 
Last edited:

Hikertrash

Member

Plus many more

Thanks. One of these days I'll start using the search function. ;)
 

Alex M

Well-Known Member
Can you charge a 48 volt ebike battery with a solar charger?

I have a Lectric XP on order and should be getting it soon. I travel in Dodge Grand Caravan. I'm thinking of adding a narrow 90 watt solar panel (80 watt output, 4.5 amps charging power) .

If possible, besides the panel and controller, what size battery and inverter would I need to charge the battery?
1) Panel and controller.
You can but it will take all day or longer yet. With 600Wh bike battery discharged to 30% you need to put 420Wh back in, 6 hours of full sun @80W output after inverter losses - and you might not get 6 hours of full sun every day. In low overcast 90W panel will output 10W, in heavy rain 2-3W, do the math. Get a bigger panel if there is more room on the roof - 100W, 140W - the biggest you can fit.

12V panels only come 160-180W max. They are not actually 12V, it's a nominal voltage while the real voltage is 17-18V. Panels larger than 180W are nominal 24V and require more expensive MPPT controller.

Solar charger is called "controller" in this industry. 10A controller will suffice, PWM type, you don't need MPPT for nominal 12V panel. Don't buy $15 Ebay controllers, they are cr-ap, don't work well and die soon, damaging expensive AGM battery.

If you're not mounting solar permanently on the roof and prefer the pains of a portable panel, consider 100W Renogy Solar Suitcase . It folds compactly and comes with solar controller, $250 total.

2) Battery and inverter.
12V coach battery - i.e. in the car - should be deep cycle type, preferably AGM if it's inside. At least 100 AH, preferably 120 AH. They are not cheap, from $200. "Marine" AGM from Walmart or Costco will do, they are not truly deep cycle but will work for a while. If it's not rated in AH, it is not deep cycle. Connecting solar controller directly to inverter without coach battery is a bad idea, you may fry the controller.

Solar is "all or nothing" affair. When there is plenty of sun you'll charge either bike battery or coach battery or both, when bike battery is full the solar power goes to coach battery, when there is no sun you'll charge bike battery from coach battery. While you're riding, the panel is charging coach battery.

If your bike charger is 4A*50V=200W, inverter with 15% losses will draw 230W from AGM so you need 250-300W inverter. Preferably Pure Sine type, not Modified Sine. Look into Samlex brand, they are good and relatively cheap: Samlex Pure Sine 350W. If your bike charger is 2A, you're good with 150W inverter. Install inverter as close to coach battery as possible, like a foot or two, and wire it to battery with at least gauge 10 cable. Starter cables gauge 6 work fine for that. Output 120V cable can be a usual household extension cable gauge 18 and length is not very important.

If your alternator is big enough, you can rewire alternator output to coach battery and charge coach battery much faster than with solar, when driving. Solar still won't hurt, it will be running quietly in the background, adding more amps, and will top-up the coach battery when you're parked.

So called "solar generators" are just a small panel with controller and small battery, total package usually overpriced for what it offers.

Hope this helps.
 
Last edited:

Hikertrash

Member
1) Panel and controller.
You can but it will take all day or longer yet. With 600Wh bike battery discharged to 30% you need to put 420Wh back in, 6 hours of full sun @80W output after inverter losses - and you might not get 6 hours of full sun every day. In low overcast 90W panel will output 10W, in heavy rain 2-3W, do the math. Get a bigger panel if there is more room on the roof - 100W, 140W - the biggest you can fit.

12V panels only come 160-180W max. They are not actually 12V, it's a nominal voltage while the real voltage is 17-18V. Panels larger than 180W are nominal 24V and require more expensive MPPT controller.

Solar charger is called "controller" in this industry. 10A controller will suffice, PWM type, you don't need MPPT for nominal 12V panel. Don't buy $15 Ebay controllers, they are cr-ap, don't work well and die soon, damaging expensive AGM battery.

If you're not mounting solar permanently on the roof and prefer the pains of a portable panel, consider 100W Renogy Solar Suitcase . It folds compactly and comes with solar controller, $250 total.

2) Battery and inverter.
12V coach battery - i.e. in the car - should be deep cycle type, preferably AGM if it's inside. At least 100 AH, preferably 120 AH. They are not cheap, from $200. "Marine" AGM from Walmart or Costco will do, they are not truly deep cycle but will work for a while. If it's not rated in AH, it is not deep cycle. Connecting solar controller directly to inverter without coach battery is a bad idea, you may fry the controller.

Solar is "all or nothing" affair. When there is plenty of sun you'll charge either bike battery or coach battery or both, when bike battery is full the solar power goes to coach battery, when there is no sun you'll charge bike battery from coach battery. While you're riding, the panel is charging coach battery.

If your bike charger is 4A*50V=200W, inverter with 15% losses will draw 230W from AGM so you need 250-300W inverter. Preferably Pure Sine type, not Modified Sine. Look into Samlex brand, they are good and relatively cheap: Samlex Pure Sine 350W. If your bike charger is 2A, you're good with 150W inverter. Install inverter as close to coach battery as possible, like a foot or two, and wire it to battery with at least gauge 10 cable. Starter cables gauge 6 work fine for that. Output 120V cable can be a usual household extension cable gauge 18 and length is not very important.

If your alternator is big enough, you can rewire alternator output to coach battery and charge coach battery much faster than with solar, when driving. Solar still won't hurt, it will be running quietly in the background, adding more amps, and will top-up the coach battery when you're parked.

So called "solar generators" are just a small panel with controller and small battery, total package usually overpriced for what it offers.

Hope this helps.

Thanks, lots of good info. The project wouldn't start until later in the summer, but you've given me a few ideas to think about.
 

mcmars

New Member
I bought this Jackery 500 watt all in one with the renogy portable 100 watt panel kit. It was discounted quite a bit below what it is now during holiday. I like that it is brainless and and easy and I could get a couple of charges on the bike since I never really drain out the battery. Only real drawback on the Jackery is it is slow to charge, but it is clean power and very handy for all kinds of stuff. https://www.amazon.com/gp/product/B07SM5HBK1/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
 

Alex M

Well-Known Member
I bought this Jackery 500 watt all in one with the renogy portable 100 watt panel kit. It was discounted quite a bit below what it is now during holiday. I like that it is brainless and and easy and I could get a couple of charges on the bike since I never really drain out the battery. Only real drawback on the Jackery is it is slow to charge, but it is clean power and very handy for all kinds of stuff. https://www.amazon.com/gp/product/B07SM5HBK1/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
This is a 520WH Lithium battery with built-in inverter and low-amp AC charger. Usable capacity ~400WH. They call this a solar generator but there is no solar in it. Not a good value for a multi-day camper with ebike since your daily energy needs could exceed 400WH, considering that you have other devices to charge too (lights, fan, radio, laptop etc). Discounted to, say, $300 I would consider it as a battery additional to main battery bank because of its light weight.

Common approach of RV weekend warriors is to carry a substantial 12V battery bank ~200-300 AH (2400-3600 WH), without solar. This is 2-3 deep cycle 12V batts @100AH each, wired in parallel, or a pair of golf cart 6V batts @220AH each, wired in series. Many also add a small portable solar or a bigger permanent solar on the roof. AGM and flooded batteries like being topped up slowly to 100%, solar is perfect for this, it's slow and silent.

OEM devices in RV or camper van are 12V and can be powered directly from 12V bank, for others they have an inverter.
 
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mcmars

New Member
This is a 520WH Lithium battery with built-in inverter and low-amp AC charger. Usable capacity ~400WH. They call this a solar generator but there is no solar in it. Not a good value for a multi-day camper with ebike since your daily energy needs could exceed 400WH, considering that you have other devices to charge too (lights, fan, radio, laptop etc). Discounted to, say, $300 I would consider it as a battery additional to main battery bank because of its light weight.

Common approach of RV weekend warriors is to carry a substantial 12V battery bank ~200-300 AH (2400-3600 WH), without solar. This is 2-3 deep cycle 12V batts @100AH each, wired in parallel, or a pair of golf cart 6V batts @220AH each, wired in series. Many also add a small portable solar or a bigger permanent solar on the roof. AGM and flooded batteries like being topped up slowly to 100%, solar is perfect for this, it's slow and silent.

OEM devices in RV or camper van are 12V and can be powered directly from 12V bank, for others they have an inverter.
I totally agree, I picked this Jackery up for just a bit more than $300, for that price it made sense, now it seems to be over priced compared to just buying a battery, controller and inverter. I have a 17 ft RV trailer and I upgraded the battery to a nice 175 amp Trojan golf cart style battery and have a total of 300 watts now of panels. I also have a prius and a clean inverter and that works very well for charging the ebike as you can idle the prius and using it as a generator as well as charge while traveling..
 
Can you charge a 48 volt ebike battery with a solar charger?

I have a Lectric XP on order and should be getting it soon. I travel in Dodge Grand Caravan. I'm thinking of adding a narrow 90 watt solar panel (80 watt output, 4.5 amps charging power) .

If possible, besides the panel and controller, what size battery and inverter would I need to charge the battery?

A 99% efficient MPPT boost Controller for a 52V Lithium Battery is what i use. It works great. Power flows from the 2 solar panels to the 2 controllers to the battery and then to the motor. No inefficient inverter is required.​

 

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