openinverter forum

Inspired by https://solarrolla.com/ and the hopefully upcoming Sion from Sono Motors I plan to use flexible Solar Panels on the roof (extended by a porch roof with solar) of an electrified VW T2 Westfalia camper to get energy for camping in the wild or get energy to charge the traction battery. So I did a search for DC to DC charge Controller for the traction battery. I only found DC to DC (12=48V) charge controllers to charge batteries in campers or with AC inverters and not 200-400 V DC output. I like to avoid losses by doing DC/AC to AC/DC to charge the traction battery with highest efficiency. I like to eliminate the AC Charger.

Short description of the project (concept/ plan):
VW T2b Westfalia, MY 78
62 kWh Nissan ePlus battery with additional air cooling (under floor) => 200-250 km distance with 80-100 km/h travel speed
Nissan Leaf Gen1 Powertrain or power reduced Tesla small rear drive unit (119 HP allowed)
Orion 2 BMS with Chademo (to get the battery at least 2-3 times a day charged on trips) DC charging

I've successfully boosted 60V/16A to 380V with the inverter charger (https://openinverter.org/wiki/Battery_Charging). That said the latter doesn't implement MPP tracking.

Look up "PV optimizers". They're MPPT converters designed to be used in series and the number in series depends on the output voltage range you're trying to cover. (Check the datasheet.) If you get a system that supports a programmable total output voltage limit, you only need a blocking diode to connect it to the battery, with the BMS as backup overcharge protection.

NiHaoMike wrote: ↑Wed Jan 01, 2020 9:04 pm Look up "PV optimizers". They're MPPT converters designed to be used in series and the number in series depends on the output voltage range you're trying to cover. (Check the datasheet.) If you get a system that supports a programmable total output voltage limit, you only need a blocking diode to connect it to the battery, with the BMS as backup overcharge protection.

That’s the direction I like to go. You’re talking about something like solar edge (https://www.solaredge.com/products/power-optimizer#/).

johu wrote: ↑Wed Jan 01, 2020 9:02 pm I've successfully boosted 60V/16A to 380V with the inverter charger (https://openinverter.org/wiki/Battery_Charging). That said the latter doesn't implement MPP tracking.

Forget to mention MPPT is the way to go

Yesterday late in the evening I found an article from Switzerland regarding EMC problems of one supplier. As I need to get EMC Testing with the converted car the risk to fail is to high to implement this feature (solar) tight up from the beginning,

https://www.uska.ch/wp-content/uploads/ ... HB9AZO.pdf

Im thinking about a solar panel as well. But went away from the high voltage battery pack charging solution. Gains are almost minimal and hardware is complicated. I now will use the 320wp panel for charging the 210A 12v system. This will allow me to be off grid and dont have a live high voltage battery pack. When camping the big batterypack is switched off. All appliances will run on the 12v. During driving it will charge the 12v. And only if not sufficient the dc-dc will come on. I also use 12v for heating (800watt golfV heater).

For me this is the safest and also cheapest solution

here's a video for anyone who missed the reference to solarrolla;