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Victron BMV700 - Price


Louw
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Every time I bought stuff, I made it my mission to register as a dealer. Controllers, panels, batteries BUT, it is more a hobby and for select customers only.

 

Originally I bought from Exsolar, and registered as a dealer, and then Dixon Batteries also started importing Victron. I am a dealer with them also.

 

Grahamstown, Collivery couriers could be about R180.00 next day.

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So Dixon or ExSolar? ExSolar is literally 5km from my house, and prices are usually reasonable, but just watch out, there is the occasional item that seems a little out of bounds. For example that VE-Direct cable that's just over R1000 but should (imho) be closer to R650. I think the BMV is on their shelf at R2.2k or something like that, or it was the last time I breezed through there.

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Yes, that VE-Direct cable, is WAY out of whack. I am sure someone with experiences in that field can make a clone quite easily, for R100 bucks.

 

Quote from Dockarl one of the Aussies I correspond with:

 

Note that you need to understand and be very careful to eliminate ground loops. It is possible to destroy the arduino and/or the BMV or bluesolar if you connect the earths together without any protection and create a voltage potential difference - in fact I accidentally did just that when I was developing this. Victron sells an isolated ttl to rs232 converter to prevent this happening, and I'd suggest using it and upconverting back to TTL on the arduino side to prevent similar issues... alternatively there there is a digital isolator IC called Adum1201 that is suitable to electronically isolate the BMV / Bluesolar from the arduino at native TTL levels and the relatively high speed (19200 Baud) used - I tried using a bog standard optocoupler but it didn't work - I found that very puzzling but after whipping out the oscilloscope I realised that the optocouplers just induce too much attenuation at these speeds due to an inherent delay in the led / photodiode part of the optocoupler circuit - meaning the arduino interprets a digital '101' as '11', and vice versa. Possible to code around but messy. If you choose not to isolate, at the very least ensure your arduino and your BMV or bluesolar are connected back to ground/-ve at exactly the same point in your circuit. My problems arose because I was using a non-isolated buck converter on the same 48v main supply as the BMV / bluesolar to power the arduino and I realised that it was introducing about 0.3v potential difference between the grounds of the BMV and the duino. Enough to liberate smoke over time. I don't want to hear of anyone else blowing the arse out of their serial ports, kids, ok? :) I DO however want to hear stories about the cool stuff you've managed to do with the duino and the great victron gear.. As an engineer I'm really impressed with the thought that has gone into their gear and their willingness to open up some of their protocols.

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Quote from Dockarl one of the Aussies I correspond with:

 

Note that you need to understand and be very careful to eliminate ground loops. It is possible to destroy the arduino and/or the BMV or bluesolar if you connect the earths together without any protection and create a voltage potential difference - in fact I accidentally did just that when I was developing this. Victron sells an isolated ttl to rs232 converter to prevent this happening, and I'd suggest using it and upconverting back to TTL on the arduino side to prevent similar issues... alternatively there there is a digital isolator IC called Adum1201 that is suitable to electronically isolate the BMV / Bluesolar from the arduino at native TTL levels and the relatively high speed (19200 Baud) used - I tried using a bog standard optocoupler but it didn't work - I found that very puzzling but after whipping out the oscilloscope I realised that the optocouplers just induce too much attenuation at these speeds due to an inherent delay in the led / photodiode part of the optocoupler circuit - meaning the arduino interprets a digital '101' as '11', and vice versa. Possible to code around but messy. If you choose not to isolate, at the very least ensure your arduino and your BMV or bluesolar are connected back to ground/-ve at exactly the same point in your circuit. My problems arose because I was using a non-isolated buck converter on the same 48v main supply as the BMV / bluesolar to power the arduino and I realised that it was introducing about 0.3v potential difference between the grounds of the BMV and the duino. Enough to liberate smoke over time. I don't want to hear of anyone else blowing the arse out of their serial ports, kids, ok? :) I DO however want to hear stories about the cool stuff you've managed to do with the duino and the great victron gear.. As an engineer I'm really impressed with the thought that has gone into their gear and their willingness to open up some of their protocols.

 

You just have to add galvanic isolation.

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