Off grid battery charging

[matthewslack]

yes I would be wanting to carry with me on the bike I have 3x 20ah fitted already but undeseat one is a slideout so I have a spare for this a original knaap 20ah with Samsung cells i carry this with me in a backpack when doing long trips my range is about 100 miles if pushing but 120 if careful with the batteries.

That's a lot of battery.

Good side to that is that it does not matter so much about charging as you ride because the range is determined by the size of the battery. Downside is how much charging time you need, which is proportional to how much solar you have.

I have only a 1000Wh battery, 28Ah at 36V, so I rely on charging as I ride. I rarely go below 37V on the battery, which is about 50%, but frequently use 1500 to 2000Wh in a day, because it is straight from the sun.

You'll learn and maybe alter strategy with experience. For example, you might find you can leave one of the batteries behind and offset some weight against the solar.

You could get an idea of how it would work by buying one 100W panel and an Elejoy charge controller and just set them up at home and play around with it. The Elejoy has displays that tell you what's happening, and if you added a cheap Wh meter you could measure total energy harvested as well.

Always have a fuse in the circuit connecting to the battery. I have one in the solar connection too. Can't be too careful!

 

[Only-Me]

That's a lot of battery.

Good side to that is that it does not matter so much about charging as you ride because the range is determined by the size of the battery. Downside is how much charging time you need, which is proportional to how much solar you have.

I have only a 1000Wh battery, 28Ah at 36V, so I rely on charging as I ride. I rarely go below 37V on the battery, which is about 50%, but frequently use 1500 to 2000Wh in a day, because it is straight from the sun.

You'll learn and maybe alter strategy with experience. For example, you might find you can leave one of the batteries behind and offset some weight against the solar.

You could get an idea of how it would work by buying one 100W panel and an Elejoy charge controller and just set them up at home and play around with it. The Elejoy has displays that tell you what's happening, and if you added a cheap Wh meter you could measure total energy harvested as well.

Always have a fuse in the circuit connecting to the battery. I have one in the solar connection too. Can't be too careful!

Yes a lot of battery lucky my knapp is well built and takes the weight well as it is a legal two seater knapp ams black edition 250 all batteries are 36 volt with a three way splitter/ balancer so I can have all 3 on at same time and it will draw power draw power from the highest charge one then balance between them or I can use individually by switching only one on at a time this I prefer but if I am on a big hills I use all three at the same time it seems to give more power/torq but not speed.
I am thinking of putting 48 volt batteries on it at some point but will probably need to change the controller.

 

[Only-Me]

I must weigh the spare knapp battery it’s heavy enough in the backpack with my waters and essentials I carry my wife laughs and says I look like flick from the bugs life movie

 

[AndyBike]

The best solution for off-grid charging is a small petrol generator

This.

You can get a Hyundia 2.2kw genny for about £400 or a Clarks 800w for about £250
I couldn't tell you much about the Hyundia, but ive watched a few review vids on YT, and it looks ok.

Unless you are feeling spendy, in which case the preferred genny is a 2.2kw Honda. I've sailed an a few long distance cruising yachts, and that was what they were using.
The Honda one is about a grand.

 

[matthewslack]

This.

You can get a Hyundia 2.2kw genny for about £400 or a Clarks 800w for about £250
I couldn't tell you much about the Hyundia, but ive watched a few review vids on YT, and it looks ok.

Unless you are feeling spendy, in which case the preferred genny is a 2.2kw Honda. I've sailed an a few long distance cruising yachts, and that was what they were using.
The Honda one is about a grand.

Hydro generators are the goto solution for big sailing yachts these days.

 

[AndyBike]

Ive only ever heard about prop regen, but mind you it's not 'big' yachts ive sailed, more the 10-15m size.

Isnt technology a wonderful thing these days.