Interesting Victron battery specs

[booster]

I haven't followed the Victron specs much over time as they were, and still are, too high cost for me to justify, but I did just go to their site and take a look at the current specs for them.


As I said, it has been a while since I looked, but Victron seems to have gotten on the much more conservative specs, particularly for the charge rates and expected cycle life ( at least they list number of cycles based on discharge rate so can be useful). It good to see a major manufacture (seller) of lithium that is showing the difference in life based on discharge percent as there are others that still claim the same life for 100% discharge as lower amounts do. Recommended charge rates are in the now more recommended .3-.4Cl range it appears.


Lithium still has longer life than AGM, but not as extreme as claimed in the past. Charge rates are basically the same as AGM per Victron and others, although lithium has big advantage in overall charge time because of the lack of tapering amps above 80% SOC in AGM that can be in the 6-8 hour range.


The temp recommendations are interesting as they show typical charge and discharge temps that are pretty typical at the cold end but quite high on the top end. Storage temps are crazy high and low compared to most.

[avanti]

Thanks for posting this. I have been meaning to take a close look at these specs. (Just because I own a Victron system doesn't mean I know much about it yet--a lot to absorb).

The "50 below" spec for cold-weather storage is very reassuring. If reliable (and I suspect it is), it pretty much takes this issue off the table for most of us. Given that this is the single most difficult problem for storage without shore power, this is pretty good news.

[booster]

Originally Posted by avanti

Thanks for posting this. I have been meaning to take a close look at these specs. (Just because I own a Victron system doesn't mean I know much about it yet--a lot to absorb).

The "50 below" spec for cold-weather storage is very reassuring. If reliable (and I suspect it is), it pretty much takes this issue off the table for most of us. Given that this is the single most difficult problem for storage without shore power, this is pretty good news.

Yeah, the whole lithium thing is a moving target, it appears. Victron also showed in the cut sheet for the batteries that they strongly recommend against using batteries in series if you can get batteries with right native voltage. The state balancing being the issue.


I think the -45*C storage may be a misprint as it is not really in the realm of temps anyplace that might use them would be except at the poles. The high temp at 70*C is also more than any person could stand to be in. I think those temp convert to like -50*F to nearly 160*F so just can't be correct. If it was +50*F to 70*F it would be more in line with what I have seen in the technical papers.


A call or email to Victron may be in order to see what is going on.

[@Michael]

Originally Posted by booster

I think the -45*C storage may be a misprint as it is not really in the realm of temps anyplace that might use them would be except at the poles

Or perhaps NE Minnesota? A few spots up there hit -50F in the last few years.

As far as applicability, I suspect that data from a company like Victron is not applicable to non-Victron batteries. The chemistry of LiFePo4's can vary slightly from one mfg. to the next, and it's not possible to know which mfg. has what.

FWIW - my cells claim to have a discharge limit of -30C, but a storage limit of only -20C. Not sure what to make of that.

[avanti]

Originally Posted by booster

I think those temp convert to like -50*F to nearly 160*F so just can't be correct.

Maybe. But it isn't so obvious to me. What you say is true of RVs, but there are a lot of uses for lithium/solar setups that involve installations in remote, mountainous locations, where -50F isn't unheard of. Even Minnesota has seen -60F from time to time. And, it isn't the average low that matters for permanent installations, it is the lowest low.

My optimistic thought is that maybe the old "never below zero F" advice was pulled out of somebody's ear, and we are now starting to see real data. Hope so, anyway.

[avanti]

Poking around a bit, it appears that the -45C storage temp is legitimate:

https://community.victronenergy.com/...r-storage.html

Note, in particular this sentence:

Only Victron and Mastervolt (which both use Winston cells (LYP) spec the batteries to -45C

I have been reading an increasing number of comments that have started to question whether the low-temperature storage risk is real. Dunno.


Here's another discussion:
https://diysolarforum.com/threads/li...atteries.2867/

[W9TR]

Thanks booster. This is great info.
I think Victron also has one thing going for them - they are probably NOT lying about their specs.

I’m following all of this with great interest as my AGM batteries continue to preform well. Someday they won’t, and I’ll be well informed thanks to this group.

Tom

It got to -35 F last winter here at our place in WI.