validate my LiFePO4 upgrade

[MooGroc]

I'm planning on replacing my 3 very dead AGMs with
LiFoPO4 and would love some feedback on the specifics of my
plan.

Currently, I have a 3 West Marine AGM (2 G31, 1G27) house
bank that barely fit in my battery compartment. They were
purchased in 2008 by the PO. Though completely shot this
past summer, they served me very well up until then.

I have a separate little Lifeline AGM GPL-1400T for the
second bank that starts my Yanmar 3JH.

For charging, I have:

1. Kyocera 140W solar panel with a Blue Sky 2512ix HV controller
2. Sunpower 110 Flex panel with a Victron 75/10 controller
3. Powerline 120 amp alternator with Powerline 10-170 ext regulator and Powerlinei solator to charge both banks
4. Xantrex Shore charger that never gets used as she's on a mooring

My plan is the replace the 3 AGM house bank with a
KILOVAULT 3600 HLX 3600WH 300 AH 12V LITHIUM SOLAR BATTERY-V3.

This will save (210-84) 126lbs and increase my usable amp
hours by about 75 amp hours versus a replacement Lifeline
AGM bank.

I figure I need to replace the alternator regulator with a
Balmar MC614 to avoid burning out the alternator. I also
need to replace the Blue Sky solar controller with a more
programmable controller.

I plan to replace the alternator v-belt with a serpentine
no matter which battery solution I decide on.

I assume the AGM starter battery and the isolator will
protect the alternator from a BMS disconnect.

Does this sound like a reasonable, albeit expensive plan?

[Pete7]

Originally Posted by MooGroc

They were purchased in 2008 by the PO. Though completely shot this past summer, they served me very well up until then.

Bloody marvellous actually

Originally Posted by MooGroc

Does this sound like a reasonable, albeit expensive plan?

Yes but as you say expensive.

Given the solar do you really need the Balmar alternator? would some of the saving made by keeping the existing alternator be better invested in more or upgrading the solar perhaps.

If you had an absolute of say 280Ah with AGM, could you get away with 200 Ah of LFP? that would reduce the cost quite a bit.

How do you plan to wire all this? all charging into the engine start battery and then a B2B to the LFP bank? or perhaps have the engine charge the start battery plus a smaller B2B to charge the LFP, but also have the solar connected to the LFP?

What happens when the LFP bank is full and the BMS disconnects the bank so it isn't over charged. Were is the power for the lights, VHF and auto pilot coming from? I am still pondering this one.

Pete

[MooGroc]

Originally Posted by Pete7

Bloody marvellous actually

Yes, I must be crazy to consider changing anything after such an amazing run with the old AGMs.

Originally Posted by Pete7

Yes but as you say expensive.

Given the solar do you really need the Balmar alternator? would some of the saving made by keeping the existing alternator be better invested in more or upgrading the solar perhaps.

I wouldn't be changing the alternator, just the regulator.

Originally Posted by Pete7

If you had an absolute of say 280Ah with AGM, could you get away with 200 Ah of LFP? that would reduce the cost quite a bit.

How do you plan to wire all this? all charging into the engine start battery and then a B2B to the LFP bank? or perhaps have the engine charge the start battery plus a smaller B2B to charge the LFP, but also have the solar connected to the LFP?

What happens when the LFP bank is full and the BMS disconnects the bank so it isn't over charged. Were is the power for the lights, VHF and auto pilot coming from? I am still pondering this one.

Pete

I would wire it for all charging to the LFP. The isolator would help keep the starter battery charged, but I hadn't thought about how to get the starter battery some solar. I wonder if the solar charge controllers and be programmed to charge the LFP and, secondarily, the AGM.

It's my understanding that the BMS shouldn't shut off unless something is not right. In this rare (hopefully never) scenario I can switch to the starter bank as my house bank
for a short time while I address the BMS issue.

Thanks for the input.

[Randy P]

Not sure if this helps, but I’m planning to wire all my charging sources to a single Blue Sea 9002e battery switch: Victron IP67 AC-DC battery charger, Victron Smart MPPT 100/30 solar controller, and 70A alternator. Underway, the alternator will charge to single FLA engine battery, with switch on “1” for that battery. Engine off, away from shore power, 370W of solar via the MPPT will charge the 2 100AH Battle Born LFP batteries (in parallel), with switch on “2” or switch on “All” to charge both engine and house banks (the MPPT will be set for LFP charging algorithm). Back at dock, with shore power, the Victron IP67 will charge the engine battery (FLA) and solar can handle the LFP house bank. My biggest amp “hog” is the Norcold AC/DC fridge, which I usually leave running, but with shore power available it runs on AC so there is no drain on the house bank. The Battle Borns have built in BMS and all loads off them are fused properly and run through a bus bar. I also have a Victron Orion Smart 12/12-30A DC-DC charger wired from the engine battery to the LFP bank, which will control any amp spikes off the alternator to the LFP bank while the engine is running.

[Pete7]

Originally Posted by MooGroc

The isolator would help keep the starter battery charged, but I hadn't thought about how to get the starter battery some solar. I wonder if the solar charge controllers and be programmed to charge the LFP and, secondarily, the AGM.

It's my understanding that the BMS shouldn't shut off unless something is not right. In this rare (hopefully never) scenario I can switch to the starter bank as my house bank
for a short time while I address the BMS issue.

Thanks for the input.

If all charging goes to the LFP house bank, how about a Voltage Sense Relay (VSR) between the house bank and the engine start battery? We have one the other way around, engine battery feeds the house bank. It connects when the voltage is above 13.2v and disconnects when it drops below 12.8v.

I still still think your LFP battery will shut down once the solar panels have fully charged them up even though the Victron MPPT has a lithium setting. Victron has a battery protect which might be worth investigating, though I haven't used one. Separate load and charge bus bars would be good here so that the charge is disconnected, but any loads like VHF remain powered by the house battery.

https://www.victronenergy.com/batter...attery-protect

[s/v Thea]

I installed 800ah of LFP in 2011. I have a LA starting battery. All charge sources go to LFP with voltage combiner for charging starting battery. Problem was I never really charged my starting battery that well as cutoff to LFP was 14v and hardly ever got there, so over time my starting battery lost charge and would get to the point of not being able to start engine. Last year I installed a DC-DC battery charger ( https://www.renogy.com/12v-dc-to-dc-...ttery-charger/ ) Only being using it for one season but seems to be doing the trick

[ALBACHIARA]

Hy
I would like to switch to LiFePO4 too, but having all the energy sources without the Lithium option, I'll do this: all the sources connected to the engine battery (lead acid) and from those the 30 or 60 A Sterling BtoB charger I'll charge the lithium (integrated or external bms )
So alternator and everything else will be able to charge my lithiums correctly, this is my idea

[tomsnrg]

Originally Posted by ALBACHIARA

Hy
I would like to switch to LiFePO4 too, but having all the energy sources without the Lithium option, I'll do this: all the sources connected to the engine battery (lead acid) and from those the 30 or 60 A Sterling BtoB charger I'll charge the lithium (integrated or external bms )
So alternator and everything else will be able to charge my lithiums correctly, this is my idea

This is what I went for last year for a friends boat, using the Victron Orion Smart DC-DC 30A BtoB charger.

This limits the load on the alternator which remained the same old standard Volvo that does his job since 15 years. Electrical installation is simple separating the Optima Lead-Acid starter battery tension level from the LiFePo battery tension.
The issues I have are the Orion DC-DC delivering in excess of 35A when cold and absorbing consequently, getting pretty warm when in operation due to 80% efficiency (70W-90W of heat is relevant). It also does not (yet) have the normally very exhaustive Victron Bluetooth interface. No way to limit charge Amps fro example.

I like this setup quite a bit, no battery separator, short and efficient positive wiring from alternator to starter motor and optimal battery tension and charge level. The Victron DC-DC will get better with time, in the meantime I'll look into the Sterling.

[Robhwa]

Originally Posted by s/v Thea

I installed 800ah of LFP in 2011. I have a LA starting battery. All charge sources go to LFP with voltage combiner for charging starting battery. Problem was I never really charged my starting battery that well as cutoff to LFP was 14v and hardly ever got there, so over time my starting battery lost charge and would get to the point of not being able to start engine. Last year I installed a DC-DC battery charger ( https://www.renogy.com/12v-dc-to-dc-...ttery-charger/ ) Only being using it for one season but seems to be doing the trick

A good strategy...I use this one, and so-far-so-good

https://www.renogy.com/dcc50s-12v-50...ger-with-mppt/

takes up to 50 amps from alternator and/or solar (two inputs), set up for regular starter battery and LiFePO4 house mix, and will keep the starter charged from the solar cells after house batteries charged. You bring alternator input from starter battery, and it monitors both battery systems. Really amazing, actually. Only downside is it is 12 volts only, no series for solar (20 volt max input) or batteries, only parallel.

[newhaul]

Originally Posted by MooGroc

I'm planning on replacing my 3 very dead AGMs with
LiFoPO4 and would love some feedback on the specifics of my
plan.

Currently, I have a 3 West Marine AGM (2 G31, 1G27) house
bank that barely fit in my battery compartment. They were
purchased in 2008 by the PO. Though completely shot this
past summer, they served me very well up until then.

I have a separate little Lifeline AGM GPL-1400T for the
second bank that starts my Yanmar 3JH.

For charging, I have:

1. Kyocera 140W solar panel with a Blue Sky 2512ix HV controller
2. Sunpower 110 Flex panel with a Victron 75/10 controller
3. Powerline 120 amp alternator with Powerline 10-170 ext regulator and Powerlinei solator to charge both banks
4. Xantrex Shore charger that never gets used as she's on a mooring

My plan is the replace the 3 AGM house bank with a
KILOVAULT 3600 HLX 3600WH 300 AH 12V LITHIUM SOLAR BATTERY-V3.

This will save (210-84) 126lbs and increase my usable amp
hours by about 75 amp hours versus a replacement Lifeline
AGM bank.

I figure I need to replace the alternator regulator with a
Balmar MC614 to avoid burning out the alternator. I also
need to replace the Blue Sky solar controller with a more
programmable controller.

I plan to replace the alternator v-belt with a serpentine
no matter which battery solution I decide on.

I assume the AGM starter battery and the isolator will
protect the alternator from a BMS disconnect.

Does this sound like a reasonable, albeit expensive plan?

Here is my setup
250ah lfp
200 watts solar via pwm set to 13.8v
A 55 amp stock Chevy alternator ( adapted to my westerbeke 10-2) running via a 40amp b2b. To the lfp. I also have cutoff switch in the exciter wire to manually disconnect the alternator.

Now my one question would be is your Powerline 10-170 ext regulator adjustable to charge lfp at ( imo13.8 is best for longevity) ? If so why change controllers.?
Run a 15 amp dc to dc charger to keep start battery up.
Add in a small lawn tractor fla ( cheap sacrificial) to protect the alternator in the unlikely event of disconnect.
Likely you will not need the alternator 90% of the time to charge. ( remember lfp are happiest between 20% and 80% charged.

[MooGroc]

Originally Posted by Randy P

Not sure if this helps, but I’m planning to wire all my charging sources to a single Blue Sea 9002e battery switch: Victron IP67 AC-DC battery charger, Victron Smart MPPT 100/30 solar controller, and 70A alternator. Underway, the alternator will charge to single FLA engine battery, with switch on “1” for that battery. Engine off, away from shore power, 370W of solar via the MPPT will charge the 2 100AH Battle Born LFP batteries (in parallel), with switch on “2” or switch on “All” to charge both engine and house banks (the MPPT will be set for LFP charging algorithm). Back at dock, with shore power, the Victron IP67 will charge the engine battery (FLA) and solar can handle the LFP house bank. My biggest amp “hog” is the Norcold AC/DC fridge, which I usually leave running, but with shore power available it runs on AC so there is no drain on the house bank. The Battle Borns have built in BMS and all loads off them are fused properly and run through a bus bar. I also have a Victron Orion Smart 12/12-30A DC-DC charger wired from the engine battery to the LFP bank, which will control any amp spikes off the alternator to the LFP bank while the engine is running.

This is helpful, if only just to get me to look at things differently.

Because all my existing charge sources can handle charging two different banks,
I never have to think about my battery switch for charging reasons. I'd hate to give up that luxury.

Maybe I need to better understand how a DC-DC charger works and if I should consider one.

[MooGroc]

Originally Posted by Pete7

If all charging goes to the LFP house bank, how about a Voltage Sense Relay (VSR) between the house bank and the engine start battery? We have one the other way around, engine battery feeds the house bank. It connects when the voltage is above 13.2v and disconnects when it drops below 12.8v.

Yeah, this might make sense. But as the OP pointed out, one has to make sure the secondary bank gets the juice it needs to get charged.

Originally Posted by Pete7

I still still think your LFP battery will shut down once the solar panels have fully charged them up even though the Victron MPPT has a lithium setting. Victron has a battery protect which might be worth investigating, though I haven't used one. Separate load and charge bus bars would be good here so that the charge is disconnected, but any loads like VHF remain powered by the house battery.

https://www.victronenergy.com/batter...attery-protect

My (possibly incorrect) understanding is that if all the charging sources are custom programmable, they would not bring the LFP voltage up to the point where the BMS shuts it off even when reaching 100% charged.

[MooGroc]

Originally Posted by newhaul

Here is my setup
250ah lfp
200 watts solar via pwm set to 13.8v
A 55 amp stock Chevy alternator ( adapted to my westerbeke 10-2) running via a 40amp b2b. To the lfp. I also have cutoff switch in the exciter wire to manually disconnect the alternator.

Now my one question would be is your Powerline 10-170 ext regulator adjustable to charge lfp at ( imo13.8 is best for longevity) ? If so why change controllers.?
Run a 15 amp dc to dc charger to keep start battery up.
Add in a small lawn tractor fla ( cheap sacrificial) to protect the alternator in the unlikely event of disconnect.
Likely you will not need the alternator 90% of the time to charge. ( remember lfp are happiest between 20% and 80% charged.

There is a potentiometer on the Powerline 10-170 that the instructions say I can use to lower the sense point to 13.8.

I thought one big reason I need a smarter regulator is because sometimes the alternator will be called upon, when the LFP is low (20%), to dump lots of amps in to the LFP and this can cause the alternator to overheat and fry.

[philcun50]

The idea of charging LiFePO4 batteries with a DC2DC charger seems dumb to me. My LiFePO4 batteries can be charged with up to 150amps, 50amps each. I would need 3 40amp chargers but I would still need to get the alternator to output enough to supply them.
This is what I have already done and so far works really well. 2017 lead acid house batteries died. Replaced them LiFePO4 and wired them in parallel so the leads to each battery were exactly the same length and size. I went cruising and found the Valeo 125amp alternator would not charge them. Only put out 14.1volts at alternator and less voltage drop at batteries. Would start charging at 95amp but quickly drop to 40amps. 400w of solar no help. Would have to retreat to a marina after about 3 days as charge just got less and less each day.
When I returned home I put in larger shorter cables from alternator to batteries and a Balmar external regulator to control alternator to charge the LiFePO4 house batteries (360ah) and a cheap DC2DC ($100) charger that only charges when engine control is on, to charge bow thruster batteries and engine start battery, both lead acid. To test this I started the engine a few times and ran below to check the charger was operating but it didn’t charge for long and that is all it needs. I rarely use the bow thrusters for long but it is now 2 years since I did all this and all is good. Use about 20% of battery capacity over night. Have upgraded solar so it actually has some effect. On a good day it supplies the fridge load and we get a few percent of charge. In the afternoon I run the engine for about 35-40 minutes to replace the lost 20% but as batteries are LiFePO4s they don’t need to be charged to 100% rarely go below 50%.
Further to this I put in a Rule Inline blower fan which I have just cable tied to the engine mount and it blows air from bottom of engine bay over the alternator so hot air coming out of alternator is not being sucked back into the alternator, this resulted in the Balmar not cutting back due to alt temperature and a gain of 15amps some of which went to running the blower. Further to this I put a longer serpentine belt on so I could rotate the alternator on its pivot point out away from the exhaust manifold and drilled a pile of 20mm holes in the belt guard to improve air flow across the alternator. The alternator controlled by Balmar regulator now can put out 114amps long term at about 83°C which is really good for a 125amp alternator and with DC2DC charger looking after the lead acid batteries I am very happy so far. The boat is kept in a marina pen most of the time so shore power is on.
Due to COVID-19 we haven’t left Lake Macquarie, NSW, Australia for possibly 2 years but have spent plenty of time anchored around the lake. Did find that after 40 minutes of engine time to charge batteries that we didn’t have hot hot water so I got insulation and we wrapped the metal relief valve and metal pipes where they come out of the hot water tank and we now still have hot water in the morning and as the water temperature is higher when we start to charge the batteries it is hotter after the 40 minutes of charging.
The TV antenna has just stopped working so we have had to resort using the internet and Chromecast to watch TV, life is tough!

[MooGroc]

Originally Posted by philcun50

The idea of charging LiFePO4 battles with a DC2DC charger seems dumb to me. My LiFePO4 batteries can be charged with up to 150amps, 50amps each. I don’t want to push the boundaries but want get them charged quickly.
This is what I have already done and so far works really well. 2017 lead acid house batteries died. Replaced them LiFePO4 and wired them in parallel so the leads to each battery were exactly the same length and size. I went cruising and found the Valeo 125amp alternator would not charge them. Only put out 14.1volts at alternator and less voltage drop at batteries. Would start charging at 95amp but quickly drop to 40amps. 400w of solar no help. Would have to retreat to a marina after about 3 days as charge just got less and less each day.

I don't understand why the 400w of solar didn't help? Was it simply because you used so many amps during the day to run the boat that there were no excess solar amps to go to recharging the batteries?