Yet Another Lithium Wiring Question

[Zoodles]

Sorry....

I have searched the forums and think I have come up with my final design... just looking for any red flags in this?

I left the 1,2,Both switch so that I can isolate the starter and for use when running the windlass (thought the windlass current might trip the LifePO4 BMS?). Wiring the alternator and shore power charger through a DC-DC charger like Victron Orion ...

Thanks for any comments.

[Cwens]

Originally Posted by Zoodles

Sorry....

I left the 1,2,Both switch so that I can isolate the starter and for use when running the windlass .

Thanks for any comments.

In your diagram the starter, windlass, and house load remain connected to each other irrespective of the position of the 1/2/Both switch. Some experts recommend isolating the electronics from the starter while cranking the engine (and, to a lesser degree, isolating the electronics from the windlass when running it) because of voltage fluctuations resulting from switching a big inductive load. Also, how does the isolator / DC-to-DC charger combo behave when the switch is in the "both" position? I am not qualified to give you specific advice, though.

[Zoodles]

Hi Chris and thanks for the reply...
Re your first comment, the starter (and windlass) to "common" on the switch has always been factory wired that way and so far have had no problems or issues...
Re your comment on the isolator/DC-DC charger... I don't know as this has not been wired or tested yet.

[Zoodles]

Is the isolator even necessary??

[brokentiller]

I am using a Victron Orion DC-to-DC charger as the isolator between a FLA starter battery (attached to the alternator) and LiFePO4 house bank on a relatively similar wiring update on my 1987 Nonsuch 30. I would assume that the extra isolator would be redundant.

[hjohnson]

What we're doing on our boat is a bit simpler than what you have there. We have a LiFePO4 house battery (460AHr DIY battery), and a group 24 starting battery for the engine.

All charging sources (Solar, Inverter/Charger, Alternator) connect to the LiFePO4 bank, and the starter motor is maintained by an 18A Orion-TR charger. The only thing running off of the starter battery is the engine (and instrument panel) as well as the battery monitor for the starter battery.

If we were to wind up in a situation where the Orion failed, and our starter motor ran down, then we could probably re-wire on the fly, but we didn't think it was worth putting that in. Group 24 starting batteries, used only for starting purposes, are pretty damned reliable. If we do have an issue, we should learn about it pretty quickly as the starter battery is monitored.

[goboatingnow]

Originally Posted by hjohnson

What we're doing on our boat is a bit simpler than what you have there. We have a LiFePO4 house battery (460AHr DIY battery), and a group 24 starting battery for the engine.

All charging sources (Solar, Inverter/Charger, Alternator) connect to the LiFePO4 bank, and the starter motor is maintained by an 18A Orion-TR charger. The only thing running off of the starter battery is the engine (and instrument panel) as well as the battery monitor for the starter battery.

If we were to wind up in a situation where the Orion failed, and our starter motor ran down, then we could probably re-wire on the fly, but we didn't think it was worth putting that in. Group 24 starting batteries, used only for starting purposes, are pretty damned reliable. If we do have an issue, we should learn about it pretty quickly as the starter battery is monitored.

This is the best and most efficient approach assuming all charge sources are controllable by the BMS.

[Zoodles]

I assume that your alternator is externally regulated and that you have set parameters for the LifePO4 charge parameters?
Without the long absorption and float levels the Lead acid start batt might be chronically undercharged, but that probably isn't too much of a concern.
How long have you had the system in effect? Curious in longevity and charge rates...

[smac999]

ged rid of the isolator and run the alt and charger straight to engine bank. then connect dc to dc charger from eng battery to house battery.

then replace that 1-2-all battery switch to separate the house and start systems out. an on / off swtich for each is easiest. connect windlass to start battery switch if worried about current.

[hjohnson]

Originally Posted by Zoodles

I assume that your alternator is externally regulated and that you have set parameters for the LifePO4 charge parameters?
Without the long absorption and float levels the Lead acid start batt might be chronically undercharged, but that probably isn't too much of a concern.
How long have you had the system in effect? Curious in longevity and charge rates...

I assume you were referring to me. We’re just in the process of building the system out, but due to the integration between the BMS and the Wakespeed, there isn’t actually much to configure. The Wakespeed is slaved to the BMS, and the BMS will be seeing both voltage and current limits. The regulator just does whatever the BMS asks (assuming the alternator is capable of it).

The biggest issue is going to be thermal back off on the alternator, which is likely going to be affected by our relatively small engine compartment. If we find the need to do a heavy engine recharge, we’ll likely pull off the engine cover and let the alternator breathe better.

[Zoodles]

Yes, Know what you mean... I have an 'Overkill' BMS it's a relatively 'smart' device, but I'm not sure how much affect it can have on the regulator. I have a Balmar MC-614 which does have a temp sensor for the alternator and can therefore scale it back if it overheats because I, like you, have a small frame alternator...
I have since revised my circuit and now will eliminate the DC-DC charger. In order to adhere to my "KISS" approach, which will save money and ultimately be easier to troubleshoot and repair when we spend our annual 2 month trips to the remote Central and North BC Coast.
I have configured the alternator and MPPT to charge for LifePO4 parameters and the AC charger for lead acid. With the appropriate switches I can charge or send the load to either bank if necessary.

[hjohnson]

Originally Posted by Zoodles

Yes, Know what you mean... I have an 'Overkill' BMS it's a relatively 'smart' device, but I'm not sure how much affect it can have on the regulator. I have a Balmar MC-614 which does have a temp sensor for the alternator and can therefore scale it back if it overheats because I, like you, have a small frame alternator...
I have since revised my circuit and now will eliminate the DC-DC charger. In order to adhere to my "KISS" approach, which will save money and ultimately be easier to troubleshoot and repair when we spend our annual 2 month trips to the remote Central and North BC Coast.
I have configured the alternator and MPPT to charge for LifePO4 parameters and the AC charger for lead acid. With the appropriate switches I can charge or send the load to either bank if necessary.

The Balmar MC-614 is reasonably smart and can do most of the work of charging Lithiums. The one thing you'll want to do is get a relay/contact closure type signal from your BMS that will trigger the MC-614 to kill the alternator field before it hits the breaker, and/or configure the 614 to stop charging at a voltage below the cutoff.

[Zoodles]

Originally Posted by hjohnson

The Balmar MC-614 is reasonably smart and can do most of the work of charging Lithiums. The one thing you'll want to do is get a relay/contact closure type signal from your BMS that will trigger the MC-614 to kill the alternator field before it hits the breaker, and/or configure the 614 to stop charging at a voltage below the cutoff.

Not sure if I will need to do that in my case, because the alternator will still 'see' the Reserve/Start battery in the event of a load dump from the BMS...?

Thanks for the reply. Look forward to hearing more about your project. My batteries are on a slow boat and won't arrive to late June at earliest...

[lateral]

Originally Posted by smac999

ged rid of the isolator and run the alt and charger straight to engine bank. then connect dc to dc charger from eng battery to house battery.

then replace that 1-2-all battery switch to separate the house and start systems out. an on / off swtich for each is easiest. connect windlass to start battery switch if worried about current.

SMac,
Can you explain the reasons for getting rid of Argofet apart from not-so-good profile for charging Engine battery please?
Does the Victron Orion smart dc- dc support LFP house to start charging. with battery isolation?
Cant find that scenario in documentation.
Thanks.

[hjohnson]

Originally Posted by lateral

SMac,
Can you explain the reasons for getting rid of Argofet apart from not-so-good profile for charging Engine battery please?
Does the Victron Orion smart dc- dc support LFP house to start charging. with battery isolation?
Cant find that scenario in documentation.
Thanks.

The ORion doesn’t care whether its power source is LFP or Lead Acid. You set it for a charge profile for its output, and it goes and does it.

My setup has all my charging sources (Alternator, Inverter/Charger, Solar) wired to the LFP bank, then an 18A Orion-Tr in the loop to keep my starting battery topped off.

I’m running a Victron based system, with a DIY LFP battery and a Wakespeed alternator regulator, but you can do this with a balmar MC-614 as well, just not as elegantly.