Hi all, i have salt batteries and they are working fine! I wish Victron adds it as an option in the battery manu. And I wish people buy salt instead of lithium! And I wish a nice uplifting corner here for this topic!
Hello and welcome to the forum 
Definitely an interesting topic for the future. You can configure your own battery.
Please take a few pictures of your batteries… because unfortunately they need a lot of space to achieve the same capacity as LifePo batteries…
These batteries also require very slow charging to achieve full capacity.
Who says such a thing? The opposite is true.
The previous salt batteries I’ve seen needed to be charged over 20 hours for full capacity. PV off grid systems need better than C/2 (2 hour charge)
Depends if these are sodium ion or salt water batteries…. No product data yet on Natrium company website.
You write about other things than what is meant above
and they do not need a lot of space! they are just very good and very nature friendly compared to all other destructive materials to local populations and ecosystems.
With Sodium batteries you have to take into account that the voltage range is a lot bigger as compared to LiFePo4.
That means in practice that when the battery operates in the lower SOC range, the current gets higher can be found in most manuals (those assume LiFePo4 or lead based batteries)! So you need to size the DC-cables accordingly.
Also the energy density is half of lithium. I can make a 3.3kWh li battery that weighs 33kg. Equivalent in Na ion would be 66 - 75kg. Li pack I can lift on my own, no chance with the Na-ion battery.
However, the extended voltage range permits an easier drop in replacement for lead batteries than Lithium does. For now, I’ll stick with Li, due to the pack weight.
Just got curious and dig some fast numbers: for the density looks like it’s closing:
for Li it’s 314 Ah x 3.2 V / 5.6 kg = 179 Wh/kg;
for Na it’s 210 Ah x 3.1 V / 4.7 kg = 138 Wh/kg.
But still it is ~ 20.8 Wh per Euro for Li vs 11.4 Wh per Euro for Na (Wistek, CN stock), let’s wait for some time.
And the extended voltage range is two sided sword: easier to find SOC, but it could be challenging to use all of the range for loads.
Still very scattered info on cold weather performance: some sources say it’s fine even up to -45 C, some limits to -20 C with seriously limited currents. And haven’t seen reliable info how bad it could be below these limits - if there is no permanent damage (except probably some loss of capacity), it’s game changer for outdoor off grid systems here.
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