Wanted: small buck-boost mppt for solar ebike charging

[qwerkus]

Hello,

I'm working on a solar module to charge my ebike on long tours. Nothing fancy, just a 150-200w flex mono panel + controller. Now I have no experience with mppts (Maximum Power Point Tracking) - can anyone share his experience in this domain ? The module has to boost the pv voltage of 18-24V to 54V to be useful, and ideally lightweight and waterproof.

Something like this, but smaller and with wp enclosure:


Thanks!

 

[harrisonpatm]

My experience is with a controller like this, or similar:

Amazon.com : POWLSOJX MPT-7210A 24V/36V/48V/60V/72V MPPT Solar Battery Charger Panel Digital Charge Controller 10A Boost Voltage Module : Patio, Lawn & Garden

Amazon.com : POWLSOJX MPT-7210A 24V/36V/48V/60V/72V MPPT Solar Battery Charger Panel Digital Charge Controller 10A Boost Voltage Module : Patio, Lawn & Garden

www.amazon.com

I've used it in a couple different setups, works well, is a little difficult to change settings, but once you have it setup it's plug and go.

Keep in mind that when it comes to boosting, you're looking at "low" efficiency. That's just the nature of voltage boosting using consumer equipment. Expect 65-85%. Therefore, if you have a 200w solar panel, (which, on a bike, would be rather large) you're only looking at charging with 130-165w, max. If it's in full sunlight, optimum angle, optimum time of day, no errant shade bringing the total panel output down.

Waterproof is something you may have to do yourself. The module I liked requires a fan for active cooling.

There's moderate reviews for this module, looks somewhat waterproof and adjustable.

For either module you'll want to make sure you have panels that are at a minimum Vmp of 16-18v. They don't like to go all the way down to 12v.

 

[qwerkus]

Thanks for your reply. The pv module will cover the trailer where there is more space and double as weather cover. Yeah, efficiency is going to be crap, but it's meant to be a range boost or emergency power, not the only power source. I'm hoping for charging places along the way.

 

[offGridDownUnder]

I do not know how much you can learn from this, but he has done it, and has Youtube videos about it as well. There may be useful detail.

Grin Solar

 

[qwerkus]

Yes I saw the solar page from ebikes.ca though there are a few things missing for my setup, since I don't use a CA. For an instance, I don't understand why there is no diode or similar protection of the mppt against heavy regen power.

EDIT: found a picture of the internals of the elejoy mppt (sold by ebikes.ca). Looks super cheap: