House Bank Upgrade; Lithium or AGM?

[jimL]

Iggy, we have two blowers in the ER, trying to cool two Cat C9 engines who have heated up the ER and are essentially Heat Sinks! The blowers don't make an appreciable difference. Thanks for asking though.

JimL

 

[jimL]

Cafesport,

We have all LED lights, and have no intention of running the HVAC on the inverter. The goal is to run the microwave, coffee maker, fresh water pump, and other smaller devices from the house bank.

My inadequate house bank is currently composed of three EV-31 batteries with a reserve capacity of 215 amp hours at a draw of 25 amps. The boat was constructed for this physical size battery - which is why I want to enhance the house bank.

Thanks for your feedback.

JimL

 

[AnnapolisJoy]

Low temperature operation

Hi there,

I upgrading my currently inadequate house bank to a total of four 8D size batteries. The electrician I am working with developed two options:

Use four RB200 Relion LiFePO4 200AH battery or

Use four 200AH Lifeline AGM batteries.

The electrician says the advantage of using the lithium battery is that these lithium batteries have built in battery monitoring systems and are
maintenance free (as are the AGM). They have twice the rated charge and discharge cycles of the AGM.

We plan to live aboard starting this fall.

Thoughts or recommendations?

Thanks - Jim

There is a danger should they be charged at low temperatures. Freezing temps are a red flag. Otherwise they are a win if properly installed and maintained.

 

[Iggy]

There is a danger should they be charged at low temperatures. Freezing temps are a red flag. Otherwise they are a win if properly installed and maintained.

Some Lithium have built in heaters just for that. The battery I am looking at when it sees a charge voltage and below 32F will turn the heater on and stop the battery from charging until its internal temp is above 32F. Its BMS will do this automatically. So its foul proof in that way.

 

[ronobrien]

A BMS is easy enough to add to your existing system, if you don't already have one.

Therefore being maintenance free is NOT an advantage, since they both are.

Good, this is a solid argument. However if you are living aboard full time then likely you'll be at the dock plugged into power. You'll only need batteries when cruising. How often do you plan to and for how many days, do you have solar to augment power generation, etc.?

Jim, you have things to consider. I realize that lithium are new, high-tech and very sexy, but the change over will be expensive, so look at this objectively and perhaps save thousands of dollars which can be spent elsewhere.

Agreed. You can't just evaluate the boat system, you have to include your "life system" to see if what you are planning (regardless of system type) works for your lifestyle. I was considering adding a water maker to mine, but I decided to wait and see if it made sense once I started cruising. During the current refit I am building in the low cost infrastructure for it to the boat so adding it later would be pretty much plug & play. Good luck.

 

[markpj23]

Outstanding Article

This article is one of the most comprehensive analyses of so-called "drop-in LiFePO batteries" I've found. Written by a member of the ABYC TE-13 technical group as opposed to 'some guy on the internet.'


It's a long read but will be of great interest to anyone considering a switch to the LiFePO batteries. Not sure if you can read the article without joining the group first, but it's well worth the trouble.


I'm not affiliated in any way - just sharing a great resource.


https://marinehowto.com/drop-in-lif...RcIkpfGSGbjHP_CV6KoXYzmEbSJ9O_I3FUWr4PCfn5L9M

 

[johnrupp]

This article is one of the most comprehensive analyses of so-called "drop-in LiFePO batteries" I've found. Written by a member of the ABYC TE-13 technical group as opposed to 'some guy on the internet.'


It's a long read but will be of great interest to anyone considering a switch to the LiFePO batteries. Not sure if you can read the article without joining the group first, but it's well worth the trouble.


I'm not affiliated in any way - just sharing a great resource.


https://marinehowto.com/drop-in-lif...RcIkpfGSGbjHP_CV6KoXYzmEbSJ9O_I3FUWr4PCfn5L9M

Good article and glad to see Rod is recovering.

John

 

[Comodave]

Outstanding article and I too am glad Rod is improving.

 

[av8tr]

I think in 5 years we won't even be having the conversation because 90% of cruising boats will have LFPs.

Absolutely right.

The lithium battery option is a good one. While you might be able to use the old charger/inverter system, you may want to upgrade to a charger/inverter better compatible with lithium batteries. (may also need a cerbo, better BMS, smart shunt, new battery cables, new terminal lugs, etc.

Add a solar panel and call it a "solar system" and get an ITC (tax credit) for the whole cost (including labor!).

 

[PennBruce]

Is this what you are referring to?

https://www.altestore.com/store/meters-communications-site-analysis/solar-monitoring-systems/victron-energy-cerbo-gx-communication-center-p41668/

Bruce

....may also need a cerbo,.....

 

[PennBruce]

Just don't get audited. My understanding is that to qualify for a solar tax credit on the entire system, the system can not have any other method for charging the batteries.

The solar panels, related wiring and electronics would still qualify for a tax break.

Bruce

Add a solar panel and call it a "solar system" and get an ITC (tax credit) for the whole cost (including labor!).

 

[Simi 60]

Absolutely right.

The lithium battery option is a good one. While you might be able to use the old charger/inverter system, you may want to upgrade to a charger/inverter better compatible with lithium batteries. (may also need a cerbo, better BMS, smart shunt, new battery cables, new terminal lugs, etc.

Add a solar panel and call it a "solar system" and get an ITC (tax credit) for the whole cost (including labor!).

We have upgraded nothing that we didn't already have with our AGM bank.

No "special" cables or lugs
No smart shunt needed
No cerbo
Inverter charger is a Victron multiplus 5000/120
Victron 702 battery monitor
Midnite classic 150 mppt
And 2500watts of solar

Midnite mppt and multiplus are both easily configured for LFP.
Took less than 10 minutes to do

Built the 840ah @ 24v batts myself (280ah @ 24v X 3)

 

[Iggy]

I just installed a Cerbo on my boat but she's on the hard right now so its not fully up and running. I see it as a I/O device that can can bring all it's input into one screen. Its ethernet connection can work with my Simrad MFD to display its data or you can use a Bluetooth (phone/tablet) or a Victron screen.

I want to monitor my amps going in and out of my house bank. From both the charger and solar panels. Another it can do for me is monitor my water tank levels from a 3 Gobius sensor. Not perfect, but the tank tender that came with the boat is very inaccurate.

 

[av8tr]

Is this what you are referring to?

https://www.altestore.com/store/meters-communications-site-analysis/solar-monitoring-systems/victron-energy-cerbo-gx-communication-center-p41668/

Bruce

That's the one I have. Works great for a lot of applications.

 

[av8tr]

I think in 5 years we won't even be having the conversation because 90% of cruising boats will have LFPs.

The basic premise is correct here. As a flyer for 25 years, I saw analogous technological and economic evolutions in avionics (e.g., GPS navigation and GPS IFR approaches). Acceptance accelerated exponentially as applications improved, we all caught up with the technology, and costs came down.

With lithium batteries, we're seeing a similar ramp-up of acceptance. I remember reading in Popular Mechanics about DIYers building Li batteries. Yikes! Then innovative battery manufacturers jumped into the market, advancing the technology and battery access. Significant complexities and safety issues remained (e.g., fires!) preventing broad-based acceptance for many of us. Further modifications and improvements were made. Fast forward to LiFePo4 and other technologies, which have eliminated the previous safety issues and the improved technologies (e.g., internal and external BMS, self-balancing, etc.) making them easier to understand and use.

In terms of costs, early on, the lithium battery installation market was a huge cash cow for marine electricians who followed and understood related AC/DC applications, including solar. I remember just two years ago getting a quote to install a lithium house battery bank for $30,000!! I didn't get it, but wow, this thing was complex with lots of components, total rewirings, etc. -- I'm not an electrician or a tech of any kind, but this was probably way more complex than it needed to be to justify the electrician's time.

For most of us, those massively complex and expensive systems are not needed or justified to get lithium batteries on our boats (to the chagrin of electricians). Now we have Smart Drop-In LiFePO4 batteries, backward compatible with many existing inverters, chargers, and battery monitor systems already on board. Costs are getting closer to AGMs. (By the way, we should be comparing "total useable AHs," not just 100h AGMs to 100ah Li battery.)

In any case, the "Guy with a Boat" is absolutely correct that in five years, we won't be having these discussions as we all catch up with the technology, applications evolve and improve, and costs come down.

 

[Mako]

Definitely the Chinese manufacturers and mass-production are driving prices down. I’m finding the new almost comparable with 2V industrial OPzS batteries