Charging Ebike From Teardrop Battery

[dvoisinet1615]

I recently did an ebike conversion and will be taking the bike camping this summer. The ebike battery is 48v and 13 aH. The range is probably 30-40 miles so I would like to be able to recharge the battery back at camp. I don’t have a generator or solar so I am wondering if there is an easy way to recharge the ebike using the teardrop battery. I have a 400 watt inverter so I was wondering if I could hook up the inverter to the teardrop battery knowing this is not the most efficient way to charge it (going from DC to AC to DC).

 

[rotus8]

What you need is a DC to DC Converter Battery Charger. I did a quick google for "DC to DC Converter Battery Charger 48v" and there are some possibilities. Be sure the charger you get is appropriate for the battery chemistry in you bike.

 

[rotus8]

Hmm, let me modify my answer a bit. Your ebike battery is 48V and 13 Ah, perfectly converted with no efficiency losses, would take 52 Ah from a 12V battery. The battery in your teardrop is something like 70 Ah all in, with actually more like 50 Ah usable without damaging the battery. The best you are likely to do with a DC to DC converter is about 80% so a full charge of the bike is significantly more than the full capacity of your trailer's battery. The DC to AC to DC will be worse. While I think your idea is possible, it probably is not reasonable.

 

[JohnC]

What is the Watt Hour capacity rating of the bike battery? There is a real chance you could draw down the house battery too far and shorten it's lifespan considerably if not just kill it.

I have a 400 Watt Hour battery that uses a 36V by 4 amp charger. I will only charge it via a solar generator. On my recent trip I tested charging my solar generators from the house battery. While it worked flawlessly, the house battery just doesn't have enough juice to fully recharge my bike battery without potentially drawing down well over 50% of it's capacity.

It would be an even bigger problem if you are running a fridge, cpap or any other device with a large daily draw.

Your best option is to purchase a solar generator and solar panel if you want to be able to top off regularly...unless you are somewhere near civilization where you can walk in and charge it while patronizing a Starbucks, McDonalds, or the like.

 

[dvoisinet1615]

Ok, I guess the teardrop battery isn’t a viable option. I will either have to use my car battery with inverter while driving or find a campsite buddy who will let me plug into their generator or solar in exchange for a beer. Thanks for your help.

 

[Randy]

Jackery 1000 battery with solar panel, nor inexpensive but a great product

https://www.amazon.com/dp/B09TKZ7KS4/ref=cm_sw_em_r_mt_dp_0JC9XNWEWVM1910E9W69?_encoding=UTF8&psc=1

 

[Sweeney]

What voltage is your bike battery? If your battery is 48 volt, thats a 4:1 ratio --- so to put 1 Ah into the bike battery, you would need to take at least 4 out of the house battery. The 100 Ah battery would at best give you 50 Ah before you've technically depleted it, this is an unfortunate part of lead acid batteries....they rate them at total capcity, not useable capacity.

Since you are looking at a ~4 times voltage increase (12->53) your available Ah changes...divides by 4. if the battery has 50Ah averrable, assuming 100% efficiency, divide that by 4 to say how many amps you would pull out of it....12.5. So fully depleting the house battery would give you 50% charge...if anything is 100% efficient.

A solar array would help, you could be stuffing pixies into the house battery while the bike is sucking them out....but I am not at all expert on solar systems on CampInn's....although the news roof mount looks really interesting.

I think I've got that right...Please some one corrct me if I'm wrong.

If I am, I'm more interested in charging by house battery from the eBike

 

[Tour 931]

I’m thinking of getting the roof mount when I get my trailer to Wisconsin. From what I hear it’s a good panel.