Nissan leaf battery pack

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Ben Ross

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hi, can anyone give me any advice about running a high voltage solar array and battery pack

i want to use a complete nissan leaf battery pack

i have found a forum post that shows how to get a bms system using the android app leafspy
would this be adequate for a home system?


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the problem im not sureabout is how to charge it? are there mppt solar charge controllers that work at 360v?

would it be possible to run the solar array at a high voltage also to reduce current and increase efficiency

any advice on a system like i describe would be greatly appreciated!!
 
Not sure about the charging at 360V, however you could use several smaller units and connect each one to an individual pack inside the skid. Each charger would bring that pack up to proper voltage.

However, I'm sure daromer has the answer to the mppt charger issue for the high voltage.
 
Might even be able to crack open the charger and find it converts to DC immediately. In that case, you just need to match DC input after the rectifying.
 
People just tend to dismantle the packs and use the cells in whatever configuration they like.
 
i get that most people disassemble these and rebuild them to their own needs and add their own bms, but it seems like lots of work when its possible to plug a bluetooth obd module directly into the battery and have a fairly neat bms on your android phone or tablet

high voltage is always going to be more efficient, isnt it? lower amps, less heat, smaller cabling lowers cost, plus possibility of greater distance between solar array, battery and house with less transmission losses

does anyone know the difference between how an ev charger and a solar charger work? i have searched for high voltage solar chargers but i can only find units that can accept hv solar arrays and still charge at a relatively low voltage, if there are no of the shelf solutions then maybe hacking the leaf charger would be the only way to go
 
BenRoss said:
i get that most people disassemble these and rebuild them to their own needs and add their own bms, but it seems like lots of work when its possible to plug a bluetooth obd module directly into the battery and have a fairly neat bms on your android phone or tablet

..,
...if there are no of the shelf solutions then maybe hacking the leaf charger would be the only way to go
Click to expand...

In what sense is the Android device a BMS?
Isn't it just displaying the cell voltages?



High voltage dc is scarily more dangerous than the ac mains. It ain't toy trains or ttl. And that is the trade-off for lower losses and lighter cables.

Unless Nissan publish chapter and verse about the pack's interfaces, limits, diagnostics, and responses to anomalies,etc you are dealing with the cells through a black box that is essentially undocumented. Which isn't a comfortable place to be.

Just a couple of reasons that some pretty savvypeople think the smart thing to do is to strip the packs down to the cells, which can then be used in a known and managed way.
 
ok so the bms is already in the black box, and with leafspy you have a visual representation of what the bms is doing

in my eyes it would be more dangerous for an untrained person to dis assemble a 360v battery with exposed high voltage bus bars as appose to plug in a nice insulated high voltage plug from their solar array/charge controller into the insulated, pre packaged, waterproof 24kwh black box

this battery is very well documented !http://www.wolftronix.com/E10_LithiumUpgrade/index.html
 
Ok, so the leafspy is an app that ties directly into the Leaf's onboard bms unit. Similar to the Grafana software used to view the data from Batrium.

So, now you just need to figure out to charge the leaf battery skid at it's full input voltage. That does pose a problem ..... (checking on some things...)

Ok, doing a quick look, I found this one:
FSM360: https://www.enfsolar.com/pv/charge-...n=enquiry_product_directory&utm_content=72803
SPC348: https://www.enfsolar.com/pv/charge-...n=enquiry_product_directory&utm_content=13516
480V 30A-250A: https://www.enfsolar.com/pv/charge-...n=enquiry_product_directory&utm_content=21305
Though, you would need to leafs in series for that one
384V 30A-250A: https://www.enfsolar.com/pv/charge-...n=enquiry_product_directory&utm_content=21305

And there's more on the site. I found this site and did a search: https://www.enfsolar.com/pv/charge-controller
 
I would try the ac charger mentioned above if it is compatible with your electric system in your country. use solar to grid tie/off grid inverter use that to charge the battery with ac charger, then use leaf battery to a high voltage off grid inverter/grid tie inverter at night.
solar--->inverter---ac charger--->leaf battery------>high voltage inverter-----household uses
Daytime-------------------------------------------night time use
Your costs would be higher but so would arcing at 360 volts
 
I am thinking of getting a nissan leaf ( car) and just charging the thing with the standard charger at 120 V, but I am looking to see if there are inverters out there that will just plug in. Lots to consider when doing this.
 
floydR said:
I would try the ac charger mentioned above if it is compatible with your electric system in your country. use solar to grid tie/off grid inverter use that to charge the battery with ac charger, then use leaf battery to a high voltage off grid inverter/grid tie inverter at night.
solar--->inverter---ac charger--->leaf battery------>high voltage inverter-----household uses
Daytime-------------------------------------------night time use
Your costs would be higher but so would arcing at 360 volts
Click to expand...

Don't do this.

A solar GTI will (using it's MPPT function) attempt to maximise the amount of current it can obtain from the source. The current available from a solar array is limited, and varies with irradiance. The current available from an EV pack is only limited by the cell design, so you'll potentially be able to pull very high 100s of amps. As soon as the GTI is connected, assuming the pack voltage is within it's operational range, the output will hit Pmax.

That's likely to be around 3.6Kw - which is fine if you can use that instantaneously, if you can't, the surplus will be exported. Smaller solar GTIs are available, but you'll still have to use the output instantaneously, or see it wasted via export.

Implementing means by which the house load data can modulate the GTI output is not a trivial task.
 
Actually i like the idea here. Use a pack as is

Searching AliExpress i came across MPPT inverters that work with 70-300V DC.
 
hermitdave said:
Actually i like the idea here. Use a pack as is

Searching AliExpress i came across MPPT inverters that work with 70-300V DC.
Click to expand...

Did you read my post ?
 
Sean said:
hermitdave said:
Actually i like the idea here. Use a pack as is

Searching AliExpress i came across MPPT inverters that work with 70-300V DC.
Click to expand...

Did you read my post ?
Click to expand...

No.. let me do that.. no solar panels yet. Initial idea was to extend economy tariff for day time usage
 
hermitdave said:
Sean said:
hermitdave said:
Actually i like the idea here. Use a pack as is

Searching AliExpress i came across MPPT inverters that work with 70-300V DC.
Click to expand...

Did you read my post ?
Click to expand...

No.. let me do that.. no solar panels yet. Initial idea was to extend economy tariff for day time usage
Click to expand...

Buy a good inverter with low self consumtion and high charging efficiency, I've been a year doing that with a mpp solar inverter and almost no saving, the inverter it self waste 200Wh doing nothing, if you can't switch it totally off easily when the batteries are low or you are in economy tariff, you will save nothing. After that year I bought the panels and now doesn't matter but that year was wasted, wasted the one year inverter guarranty and wasted a lot of cycles of cells for no money saving.

Regards
 
You overlooked Victron products. Also, check out Carel's posts in this forum, he currently uses a Sunny Island :)
 
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