12v Charging Setup

[grnd0]

Trying to figure a way to charge my H15 on trips with solar.
I have it set up now with an inverter and it works, but would
be more efficient not using inverter. The cable might be the
biggest issue.

 

[Richywalker64]

I have just fitted a solar panel to my van to charge my Jackery 1000w power station
I have also bought a spare battery which I can leave on charge while out on the bike which should give me a few days riding while off grid

Do you plan to route the solar direct to the inverter?

 

[yorkshire89]

Do you plan to route the solar direct to the inverter?

He wants to avoid using his inverter altogether for more efficiency.

I've not seen a 12V Shimano charger so not sure if this is possible yet.

 

[grnd0]

I can probably figure a way to get the correct 12v voltage
and output amps. it's the crazy cable the connects to bike
that is the biggest problem.

 

[Hardtail]

I can probably figure a way to get the correct 12v voltage
and output amps. it's the crazy cable the connects to bike
that is the biggest problem.

This comes up from time to time, but an inverter is still the easiest way that I can find.
Firstly, you need 36v as that is what your EP8 battery is rated at.
Bosch did have a 12v travel charger at one point but it only charged a battery that wasn't below a certain percentage, 30%? They come up on Ebay from time to time.
Sine inverters are in the region of 90% efficiency and modern LifePO4 batteries have a long cycle life. It's more important to make sure your inverter is turned off when not in use or put on a timer rather than worrying about the inefficiency of the inverter.
I have a 320w cigs array on my van and a Bluetti AC200max, which is rated at 36v... It's not lost on me that I convert the Bluetti 36v DC to 220v AC and back to Bosch36 v DC... But I see no way around it considering the Bosch BMS requires some patented communication with the charger to transfer the go juice into the battery.
Or is there another way..?

 

[Kingerz]

A LiFePo4 solar generator like a Bluetti is the answer. I have a video on my solution, which has freed me from mains power: here

 

[SwampNut]

Firstly, you need 36v as that is what your EP8 battery is rated at.

That's the nominal rated voltage, but the charging voltage is much higher. When full, that pack will measure 42v, so to charge it, you'll need more than 42v. The charger for my "36v" bike puts out a measured 43.some volts.

Aside from the connector, you'd need a minimum of a DC-DC converter, which is expensive for that current draw, and may not be more efficient than an inverter, depending on the quality and design of each.