Post Float-Revert to Float or Revert to Bulk???

[Soggy Paws]

Hi Al and all...

We are converting to Lithium!

As part of our re-defining our settings when moving from Gels to LifePO4's, we are trying to define a charge profile that will have a Bulk setpoint of 13.9v, a very short absorb time (with both a defined time and a defined tail current value), and NO FLOAT.

What we want is that after a period of time not floating, when the battery voltage reaches a defined voltage, we go back into BULK.

It looks like you have the configurability to do this, but there seems to be a contradiction in the documentation, and I'm just trying to figure out which it is.

On Page 19-20 of your v1.3.1 Communications document, where you describe the $CPE sentence, the description of pfResume says that reaching this voltage will cause the status to change back to Float.

But on Page 35, where you are describing the $CPP sentence allowing change to the Post Float parameters, you indicate that reaching that voltage setting will change back to BULK, not Float.

Which is it?

2nd question... I don't really need to fool around with Post Float, if I can set the Revert Volts in the Float settings to HIGHER than the Float volts.

(ie with the Float set to 13.0 and Revert Volts to 13.1).  

$CPF:8 13.0,-1,1440,0,0,13.1@

This would cause us to stay in Float (but never actually apply any amps), but to jump back to BULK when the battery sinks to 13.1.  Am I correct?  Would these strange settings cause any anomalies, either in your code or in our alternator?

With the LifePO4's, our batteries sit all day, between around 13.35 and 13.25 volts, after being charged up to 13.9 by mid-morning.  (we are dockside and not living aboard right now, however).

Thanks!  

BTW, your WS500 is getting great press in the Lithium Batteries on a Boat Facebook group.

Sherry & Dave s/v Soggy Paws

[Ben]

hello Sherry and Dave,

Your answer is still not answered?

maybe this is usefull.

Question 1:

I can not answer this question or regulator goes from post floatmode to bulk or float. Postfloat is not used many times, I never have used it.
But postfloat is only needed if you need a lower floatvoltage after normall flaot mode is finisched. (As example if you like to go to a lower flaotvoltage after 2 hours)

As you notice yourself, you dont need for lifepo4.
suggested setting:
$CPE:8 0,0,0,0@

question 2:
I would suggest:
$CPF:8 13.36,0,0,-20,-50,12.9,@
or
$CPF:8 13.3,0,0,-20,-50,12.9,@
(with 13.3 the batteries will keep on lower SOC after a fully charge, this means you loose a part off the full capacity, but maybe gain a longer lifetime)

With this profile, alternator stopped charging after bulk.
Voltage will bleed down slowly till float setting voltage is reached.
Than alterantor will start working again and produce amps, to support the load on board.

With your settings, $CPF:8 13.0,-1,1440,0,0,13.1@
After bulk the alternator stop charging and batteries will be drained till 13.0
As example after a night passage, your arrived on a anchorage with almost empty batteries.

Revert voltage in float is a usefully setting.

This setting force the alternator to bulk, useful if heavy inverters are used, for example electric cooking, etc etc.

A practical test will show or 12.9 is good enough, or maybe higher setting is needed.

Another tip:  start with alternator temperature at 85 or 95 degrees.
Go higher temp setting after checking the alternator with a infrared heatgun.

regards,
Ben

Op dinsdag 22 december 2020 om 16:30:04 UTC+7 schreef she...@svsoggypaws.com:

[fcgl...@gmail.com]

Thanks Ben and Sherry [Soggy Paws]  very useful information. ..And I had forgotten this group existed!

[Al Thomason]

Hello!   Yes, little traffic on the old mailing list..   I was spending a Sunday poking around and found this : - )

 

In addition the other answers, here is my $0.02!

 

1)      There has been a change between how Post Float works over the years.  At one time it went into FLOAT, and then another it was changed to restart a new charge cycle.  Best thing to do is look at the version source you are using and see where the case POST_FLOAT: in manage_alt() reverts to as its exit criteria. 

 

2)      I think the simplest way to turn off the alternator drive in float is set the $CPF: voltage to 0.0, that will assure it never drives the alternator during Float.  Then set you exit criteria(s) as you wish, current, AH, time, and/or voltage – all your call.

 

Of course, lots of ideas on what to do in ‘float’ mode with Li batteries, the VSR just lets you ahev the option to select the one you want!

 

OK, hope this did help.

 

And ya, the WS500 has been getting a lot of kind words.  Who knows, maybe have finally arrived!

 

-al-

--
You received this message because you are subscribed to the Google Groups "Smart Alternator Regulator" group.
To unsubscribe from this group and stop receiving emails from it, send an email to smart-alt+...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/smart-alt/abe89bc6-5fa6-47ec-b17f-3e94d47f3f86n%40googlegroups.com.

[Soggy Paws]

Thanks Ben and Al.  I just removed any post float and revert voltage settings, after playing with it a bit.  We are still in learning mode with the new LifePO4's, and Dave is adamant that we do NO FLOAT (for battery lifetime).  We have sufficient capacity and rarely get down below 13.3 anyway.  But I appreciate you taking the time to answer.

Sherry

[Al Thomason]

Not a problem.  There is still a number of idea on Li batteries, fun is you get to pick your own.  Will offer through, of the commercial venders we are working with, non are of the ‘stop all charging at float’ mindset.

 

 

Best of luck!

To view this discussion on the web visit https://groups.google.com/d/msgid/smart-alt/485f0ac2-0fc7-4797-8524-541d6efddf28n%40googlegroups.com.