Can Classic+WBJr trigger events based on Ah in/out of battery bank?

[boB]

The majority of the Classic was done before Lithium batteries became affordable.  Lead acid is still king of off grid systems because of price.

A properly designed BMS, (which all Li batteries should have,) allows the Classic work just fine with LiFePo4 batteries.

Many others are using them now with Li technology and are working.

Sure, there could be other features added to help out but how can we do that ?

It's hard enough to find people here that have the knowledge to do such engineering without having to raise the price  prohibitively high amounts to justify the work.  As it is, I am working 7 days a week and today.


AND we had to spend quite a bit on Australia only requirements on the Classic.   
You should come up some time and we will give you the grand tour and show you how our resources are being used and why it is not as simple to do what you are asking for as quickly as you (or we) would like.

Something like stopping charging at low temperatures could be added fairly easily.  After making any changes to CC code, the product has to go through a lot of testing to make sure that no new bugs have been added.  That is another reason it is not as easy you one might think to add features.

[australsolarier]

thanks Bob for responding,
i can totally see your point. the midnite classic is a first class product.
might pick you up on your invitation, maybe in  1,5 years or so.
thanks again for telling us how it looks like from your side.
greetings urs

[boB]

thanks Bob for responding,
i can totally see your point. the midnite classic is a first class product.
might pick you up on your invitation, maybe in  1,5 years or so.
thanks again for telling us how it looks like from your side.
greetings urs

Thank you !

Would be great to have you up here when it's convenient !   

Until then, enjoy your "warm" Christmas !

[Steve_S]

I  would like to strongly recommend that this article be read when contemplating how to address LFP & Lithium Ion Batteries and what the Big Deal is... it is all well explained and covered here.   Below is a couple of extracts to highlight the issues which require consideration.

https://marinehowto.com/lifepo4-batteries-on-boats/   

MISLEADING or UNCLEAR MARKETING FROM CHARGE SOURCE MANUFACTURERS:
Unfortunately most commercially available chargers, solar controllers and alternator regulators are of extremely limited design and are just not well suited to charging LFP banks. Many of the charger manufacturers have no actual experience with LFP yet they have no qualms making up “Li-Ion” charge profiles. In short, many of the LFP charging schemes may be damaging to your cells over the long haul and you may not see rated cycle life.

PLEASE DIG DEEPER WHEN A CHARGER MANUFACTURER CLAIMS A “LITHIUM-ION” CHARGE PROFILE

Many of these profiles I’ve seen can damage your very expensive LFP bank. A charger that immediately comes to mind, with a Li-Ion setting of 14.6V absorption and a 14.4V float! 14.4V float!!!

Technically 14.4V / 3.6VPC or 14.6V/3.65VPC can be safe if charging stops entirely when 100% SOC is achieved and all the cells stay in perfect balance way into the upper knee. The concern here is that this particular charger uses a bulk duration multiplied by X type of algorithm to help determine the absorption voltage duration. This is a lead acid algorithm. This type of algorithm sets or extends the absorption duration based on the length of the bulk stage. Short Bulk = Short Absorption & Long Bulk (eg: LFP) = Long Absorption. Long absorption with LFP = NOT HEALTHY

Seeing as bulk charging is very long with LFP how long do you think the LFP absorption duration will be? Holding these cells at 14.4V indefinitely (float) is well…. As Homer Simpson says. D’oh…….. Again, please do your research on how a charger operates before using it with your expensive new LiFePO4 batteries.

----
These chargers lack the ability to shorten the absorption voltage duration to be suitable for LFP.

Where these chargers also fall flat, as most lead acid chargers do, is in the lack of a dedicated voltage sense lead. Also the largest charger they make is just 60A. Kind of small for an typical LFP bank on a cruising boat. For an AC charger, a fully programmable unit is better. By fully programmable, I mean absorption duration (settable  from 0 minutes to 30 minutes or anywhere in-between), voltage fully adjustable and FLOAT SET TO OFF or below 3.40VPC. In most cases the best unit for LFP will be a fully programmable inverter/charger.

Dedicated Voltage Sensing Rant:

Here we go again.. In a nut shell there are very, very few chargers or inverter/chargers out there that offer dedicated voltage sensing. This is really quite pathetic. Sadly the charging portion of most inverter/chargers is apparently an after thought for the engineers who design them. The engineers who fail to provide dedicated voltage sense leads, on battery chargers or inverter/chargers, have failed you, the customer, when you’re seeking fast charging performance..

Who are these failures?
Mastervolt â€" No dedicated voltage sensing
Magnum â€" No dedicated voltage sensing
Xantrex â€" No dedicated voltage sensing
Which manufacturers actually care about battery charging performance?
Victron â€" Victron I/C’s have dedicated voltage sense terminals right on the main unit. Kudos to Victron!!
Outback â€" Can be done but requires FLEXNET DC & MATE Remote Control.

This is not to say Victron makes the best inverter/chargers but God damn if their engineers actually understand charging. Battery charging that is. (wink)

Follow me on this. No matter how big you size the wire for with a 130A+ inverter/charger you will still have some voltage drop between the charger and the physical battery terminals. Most charger manuals only account for wiring voltage drop but we should remember that each termination, busbar, shunt, fuse, battery switch etc. results in even more voltage drop. It is not uncommon to see 0.4V -0.8V of drop, at full charging output, even on factory installed inverter/chargers. While the I/C makers often insist you keep the unit 5′ from the batteries, this is not always possible on a boat.

In the real world, voltage drop happens, and is simply a fact of life.

How do we fix that?
Simple, dedicated non current carrying voltage sensing leads connected directly to the battery terminals so the charger can compensate for slight voltage drops in the system wiring and not enter absorption or the voltage limited charging stage prematurely.

[ClassicCrazy]

when I had my lifepo4 batteries I had the classic set up to get to certain voltage but then cut off at an ending amps. The result was it would go from absorb to float in a very short time.

Larry

[boB]

when I had my lifepo4 batteries I had the classic set up to get to certain voltage but then cut off at an ending amps. The result was it would go from absorb to float in a very short time.

Larry

I would love to see a graph of battery current vs. time for this for LiFePo4 batteries.  With a very low cut off current for starters to see how the current drops off with time at a steady voltage.

Of course, I could just Google for this maybe ?

[ClassicCrazy]

when I had my lifepo4 batteries I had the classic set up to get to certain voltage but then cut off at an ending amps. The result was it would go from absorb to float in a very short time.

Larry

I would love to see a graph of battery current vs. time for this for LiFePo4 batteries.  With a very low cut off current for starters to see how the current drops off with time at a steady voltage.

Of course, I could just Google for this maybe ?

Bob there was a previous discussion a few years back by a guy who had 24v worth of 100 ah Calb batteries ( 16 cells) . He was doing bottom balancing so drained them to just about empty to get them all level on the bottom voltage. Then the theory is you fill them up to like 95%  and it doesn't matter if the voltages are not exactly even at that point - and you don't loose much capacity because the last 5% takes a long time to charge . He didn't use a BMS . I tried doing that - but goofed up a few times cause I didn't know what I was doing and took my batteries down too low - I should have had a low voltage cutoff.

From what I remember the ending amps was 5 amps . I would have to look up what the other voltages were set for. Probably something like absorb of 3.5v per cell instead of 3.6 . And the float was low enough not to keep charging them.

Larry

[australsolarier]

ending amps should be in the specifications of the battery, in my case 0.02C
you cannot charge  a lifep4 only to 80%, at least not for a longish period.
for various reasons bottom balancing is not practical. ( but discussion about it gets very heated)
i set absorb to 3,5V and float to 3.35V, but you can go a few decimals lower
a bms (balancing and cutoffs is a must)
12V banks keep much more balanced (have on that keeps balanced for years) than a 48v battery bank
high currents unbalance more (there are small resistances on the battery terminals and naturally more discharge/charge)

i am suggesting experimenting with lithium batteries is not a good thing at all.