Victron Energy Quattro Inverter/Charger and LiFePo4

[mati@commax.co.il]

Dear Forum,

I would just like to warn every one on this forum not doing my costly mistake.

Lately I have started my own large solar project, in idea to continue and distribute it locally in my country where there is a really demand for Off Grid solutions.

My prototype was based on the next:

* Victron Energy Quattro 48V Inverter/Charger - I pick it after i saw it was picked by Martin, who I am highly value his opinion.
* 12 X 290W Canadian Solar Poly panels
* SMA Sunny Boy 3000TL20 - Grid Tied Inverter

and here comes my big misstake...

* 16 X 3.2V cells of Winston Battery LiFePo4 battery. Total of 48V (51.2 Nominal V)

After long (months... ) research, I realized LiFePo4 is the most costly effective solution for solar energy storage (Off Grid). I will post all the reason to use this technology in a separate post, if anyone would ask for it.

* 2 X LiFePo4 Cell monitors with ext. alarm for low/high voltage alert.

Here comes the sad story...

After long and hard (but still highly satisfied) installation, picking the different parts all over the word (ebay, Farnell etc...), I finally done with complete installation of my Hybrid backup Solar/Grid solution.

You might be wondering where is the issue...

So...

The LiFePo4 is a very good battery, however it has two alleged disadvantages.
1 - Volt never should get below 2.5V per cell.
2- Volt never should get above 4V per cell.

Any deviation of those two strict rules with result with damaged cell (probably for ever...)

You might ask yourself now why did I said alleged disadvantages? Ok, this is because with very cheap monitoring device, you can always know you current state of charge per cell, and using monitor device's alarm, you can program a relay, to shut down the charging/discharging of the system.

Now, the reason I choose Victron's Quattro, is because it contains 3 Aux relays + 2 sensors (Temp+Volt) so I will be able to use the monitoring alarm of my LiFePo4 batt. pack to shut down the Inverter in case of any of the cells goes below 2.5V or in case of any of cells get above 4V force the charger to stop charging (switch to inverter mode only).

To do that, I needed to upgrade my Quattro firmware to the last version, who supports flexible modification of the aux relays and sensors.

However, I realized Vicron Energy stuff do not like my idea of connecting my own LiFePo4 pack. do you know why?
They have their own Li-On batteries, and they want me to use their solution only, and undisputed refuse to send me the firmware upgrade so I could use my own LiFePo4 solution.

I must say, Victron Energy is an excellent company with outstanding products for off-grid solutions, but I must wonder what makes a reliable company like Victron to force us, the costumers to buy only their own Complementary Products, not allowing us - the customers buying our own third party batteries.

I am writing this post to prevent anyone from doing my costly mistake (about 10k USD not incl. tax etc..) and consider buying "standard" batteries (Gel, Tab, etc...) or alternatively purchasing victron's own Li-On batteries.

All the best,
Mati 

[MJLorton]

Hello Mati,

Thanks VERY much for your post. For one I would really like to hear about your choice and investigation into going the LiFePo4 route. As you might know this technology and the new Hybrid capacitor technologies are of great interest to me.

I'm really disappointed to hear to the approach VE are taking with you and I'm glad you mention it. I wonder if they are doing it for any legitimate reason (playing devil's advocate) i.e. safety etc....or just to protect and market their own branded batteries....not so nice.

Cheers,
Martin.

[kibi]

I think Victron are doing this to stop big fires from starting.
The charger in the Quattro is designed to charge lead acid batteries which have a completely different charging profile to lithium based batteries.
If you look at Victron's own line of lithium batteries, you'll find that they provide the battery sets and a Lynx Ion battery monitoring system for them. The battery sets have a CAN-BUS communication so that each individual cell within the battery set is monitored by the the Lynx Ion.
The Lynx Ion acts as an interface between the Quattro and the Lithium battery sets to correct the charging profile required by the Lithium battery sets. The Lynx Ion also communicates with the Quattro full time.

Victron do sell some products to people that are expensive and I have found ways around them, but what I have done is not anything to do with high energy components. In this case I don't think Victron are doing anything wrong here. Lithium batteries are very dangerous if mistreated. I am not talking about some sort of nanny situation either. Get one thing wrong with lithium batteries and you will have a fire. Get it wrong with a 5KWh battery and you'll have a very big fire, and lots of poisonous gases.
I dislike the words "It's for your own safety", but this time it really is justified.
 

[mati@commax.co.il]

Dear Kibi,

Friend, you have a big mistake here. There are a lot of BMS (Battery Management System) who can treat the LiFePo4 battery pack very well. I don't need Victron to help me saving the batteries, and the option for fire exist just in case you short circuit the package. In usual untreated charge/discharge (discharging below 2.5v or charging over 4v), you will "just" kill your the battery. It will swell and get lost (i know it from self experience  ).
If they will give me the ability to use the Aux sensors, I will be able to shut down the inverter/charger in case of over/under charge of individual cell, so no risk at all. It seems to me like "pure" marketing reason, to allow them push their own line of Li-On products. It seems wrong way to me. Like forcing you to buy their own solar panels for example.

Hope i was clear. In any case, I will be happy to know anyone's opinion.

Best Regards

[kibi]

OK, first I must apologise. I did not read your original post correctly. I did not realise that you were using a per cell BMS.
What you are doing seems all good to me.

Now, I do not understand why Victron are being a problem. In their own documentation which is titled "Connecting other lithium systems to Multis and Quattros", they seem to encourage the use of lithium systems from other manufacturers. You can read it here:
http://www.victronenergy.com/upload/documents/Manual%20-%20Connecting%20other%20lithium%20battery%20systems%20to%20Multis%20and%20Quattros%20-%20rev%2001%20-%20EN.pdf

Maybe you could contact Victron again and point them to their own document.
Best of luck, it will be very interesting to see the outcome of your project.