House Batteries

[Slowmo]

I didn't read all the posts but to the OP's question Renology batteries are widely used and respected in the off grid market. Their solar cells are well thought of as well. From my view as an engineer AGM remain the safest bet for boats. Personally I would hesitate to retrofit with Li ion (whatever the ion) when the battery containment system wasn't specifically designed for this type of battery.
Good article here on battery techology (ASME=American Society of Mechanical Engineers): https://www.asme.org/topics-resources/content/advancing-battery-technology-for-modern-innovations

 

[SteveK]

Scot, you may now print your business cards "Qualified and Certified" as you are self trained and any number of us here while testify you are certifiable. another dual meaning word, well you know which I mean.

 

[Don L]

I have been a full time liveaboard/cruiser for 7 years and far as I am concerned there are currently 2 choices for house batteries.

1 - if you are mainly a marina person with shorepower get inexpensive batteries whether there are FLA/SLA/AGM it, doesn't matter

2 - if you spend a lot of time off shorepower get LFP, and get the inexpensive ones of those so you don't turn it into a science project or start thinking that house batteries AREN'T a consumable thing on the boat and spend a lot of money babying them etc.

 

[slowgoesit]

Scot, you may now print your business cards "Qualified and Certified" as you are self trained and any number of us here while testify you are certifiable. another dual meaning word, well you know which I mean.

Steve, my wife will attest to the certifiable part!
Biggest problem most people face with doing their own LiFePO4 install (or pretty much any other major boat project for that matter) is that they generally only do it ONCE! By that I mean, if done correctly, it's a one and done.

1. So, first, someone with a boat has to figure out what they want, which may not be as simple as it seems, as most people don't know what they don't know.
2. Then they have to educate themselves on the project, taking the time to learn all they need to safely design/install/maintain the project.
3. Then once the project is complete. . . . . . . likely they never use that information again, ever.

The problem I have is that it seems like nowadays you hire a "professional" to do a job, agreeing to pay "professional" rates, up to $150/hr for their years of vast and in-depth expertise, so YOU don't have to do Step 2 above. . . . . and what happens is that you end up paying the $$$ rate for THEM to do step 2 above, because either they've never really done the work they claim to be qualified to perform, or they're just idiots, who've apparently forgotten everything they've claimed to have learned.

I have a big issue with paying top $$ for the "professionals" to learn their job. That's something they should have already learned, and what they're supposedly bringing to the table in order to justify the $$$ rate they're billing the customer!

Then after they "finish" the job, you end up having to do Step 2 above anyway, so you can go in and redo all the stuff they $%^*#&^@'d up in the first place.

Rant over

 

[SteveK]

I believe I have the ability to think outside the box. This has served me well over the years. Yes, I did the step 2 learning curve study. But when done, LFP is just another house bank of batteries, wiring is the same, size of wire is still is based on distance and amps. Charging profile is very different, that seems to be the biggest challenge converting a standard system designed for wet batteries. Going from 800Ah FLA to 800Ah LFP sounds the same but usable went from 400 to 800 which now requires more charging time or bigger chargers.

only one abyc certified electrician in Seattle, no wonder others need to learn on your dime.

 

[PhilPB]

LiTime 12V 100Ah LiFePO4 Battery Built-in 100A BMS, Up to 15000 Cycles, Perfect for RV, Marine, Home Energy Storage

$279 On Amazon. The prices seem to be getting lower.

 

[Mako]

This thread got me thinking, so I started checking prices on Alibaba. The cost per usable Ah for an example house bank of 8D's versus lithium grade B (from Eve) in 3.2v component form, was nearly identical. Okay, have to add in the cost of an external BMS, but still the difference wasn't that great.

 

[Simi 60]

This thread got me thinking, so I started checking prices on Alibaba. The cost per usable Ah for an example house bank of 8D's versus lithium grade B (from Eve) in 3.2v component form, was nearly identical. Okay, have to add in the cost of an external BMS, but still the difference wasn't that great.

Cost comparison of our setup here

https://www.trawlerforum.com/forums/s4/lifepo4-cost-comparison-real-life-example-62066.html

 

[rwidman]

OK, from the bit of research I have done, lithium batteries cannot be used as starting batteries, nor can they be connected in parallel with flooded cell or AGM batteries.

How is it possible to have an AGM starting battery and a lithium house bank on the same boat with a single engine and single alternator?

I could install an additional battery charger for the lithium bank, but underway, there is only the single alternator charging the batteries.

 

[Simi 60]

OK, from the bit of research I have done, lithium batteries cannot be used as starting batteries, nor can they be connected in parallel with flooded cell or AGM batteries.

How is it possible to have an AGM starting battery and a lithium house bank on the same boat with a single engine and single alternator?

I could install an additional battery charger for the lithium bank, but underway, there is only the single alternator charging the batteries.

DC2DC chargers for us

100 amp @ 24v alt to FLA starts
When starts are @ 27.2v the dc2dc start up (2x 35amp sterling)
Amps from alt then go to house bank.

As the draw is no where near the alts capacity, the temp of the alt never gets above 75c

 

[rwidman]

DC2DC chargers for us

100 amp @ 24v alt to FLA starts
When starts are @ 27.2v the dc2dc start up (2x 35amp sterling)
Amps from alt then go to house bank.

As the draw is no where near the alts capacity, the temp of the alt never gets above 75c

A had never heard of a DC to DC charger before this. Thanks.

It would certainly be an option to get a proper charging profile for Lithium batteries.

 

[Don L]

Was pretty easy for me on my 2001 boat.

The atlernator, and/or solar, and/or battery charger, charges the house LFP batteries directly. That same charge goes to my sealed lead acid start battery across FET isolator that lets charge the house bank go to the start, but not the start to feed into the house.

It was 100% the same as the boat left the Hunter facility when built (except the solar addition).

My BMS should NEVER disconnect the house LFP batteries no charge source goes that high, But if somehow all 4 were to open at same time the alternator would still be sending charge to the start battery and not burn out.

 

[mvweebles]

I have a magnasine 2012 inverter/charger with RC50 remote and renogy 8-100Ah smart LFP, the new ones with pouches instead of cylinders. This review helped.

Thanks for this. I've been a vocal detractor of Renogy - Will Prowse does a decent job. I guess I need to change my tune a bit.

Peter

 

[slowgoesit]

OK, from the bit of research I have done, lithium batteries cannot be used as starting batteries, nor can they be connected in parallel with flooded cell or AGM batteries.

How is it possible to have an AGM starting battery and a lithium house bank on the same boat with a single engine and single alternator?

I could install an additional battery charger for the lithium bank, but underway, there is only the single alternator charging the batteries.

Just a clarification. Some LiFePO4 batteries are specifically designed as start batteries:

https://dakotalithium.com/product/d...ar-truck-battery-plus-deep-cycle-performance/

 

[Don L]

Just a clarification. Some LiFePO4 batteries are specifically designed as start batteries:
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And even then it depends because "A" LFP battery not be ok as a starting battery. But a bank of then might. I asked the manufacturer of mine if the 4x100ah would be OK and they said yes.

 

[Simi 60]

And even then it depends because "A" LFP battery not be ok as a starting battery. But a bank of then might. I asked the manufacturer of mine if the 4x100ah would be OK and they said yes.

And would be engine dependent
Your 2 litre engine 12v start??? would need a lot less than our 14litre engine 24v start.

 

[rwidman]

Just a clarification. Some LiFePO4 batteries are specifically designed as start batteries:

Yes, but they are expensive ones.

 

[rwidman]

And even then it depends because "A" LFP battery not be ok as a starting battery. But a bank of then might. I asked the manufacturer of mine if the 4x100ah would be OK and they said yes.

I have a house bank of four group31 batteries and a single group 31 starting battery. For me, a bank of four lithium batteries just for starting would be impractical and more expensive than a lithium battery capable of starting my engine.

 

[Mako]

I’ve drawn the conclusion that an AGM is about as near perfect as a starter battery as there is. Just hook it up and forget about it. Happy just sitting there for years at about 100%, doing very little work in reality.

Not the same profile as a house bank of course.

 

[mvweebles]

I’ve drawn the conclusion that an AGM is about as near perfect as a starter battery as there is. Just hook it up and forget about it. Happy just sitting there for years at about 100%, doing very little work in reality.

Not the same profile as a house bank of course.

I sorta agree about AGMs. However, there are LiFePO4s that are specifically made for start batteries. If small and lightweight is the goal, might be worth the extra money. I went with an AntiGravity battery for my electric start/tilt Tohatsu 20hp. Fits in a small electrical service box. I'll post picts someday, but it's 2.5 lbs, and about the size of two paperback books.

https://antigravitybatteries.com/products/starter-batteries/restart-oem/atz10-rs/

Peter

 

[PhilPB]

I have 4 SLA'S for house and and 3 AGM's for thruster,
genny and main engine start (one each). All are heavy and the house batteries are ridiculously hard to access, especially to top the water off as they are in an area with 6" above them. I will be changing the house bank soon and they will not be replaced with SLA.

 

[slowgoesit]

Yes, but they are expensive ones.

Yep, but my post referenced LiFePO4 not okay for start, nothing about price! But I'll agree with you that the Dakota LiFe PO4 batteries come pretty dear!

And would be engine dependent
Your 2 litre engine 12v start??? would need a lot less than our 14litre engine 24v start.

Ours is not quite 14 litre's, but at 13 litres, I agree. I looked into the Dakota LiFePO4 Start Batteries, and decided that it just wasn't what I wanted, but primarily because our 24v bank is charged off of a generator direct drive off of the engine, not through the inverter charger, and the old style generator had no profile for LiFePO4.

I’ve drawn the conclusion that an AGM is about as near perfect as a starter battery as there is. Just hook it up and forget about it. Happy just sitting there for years at about 100%, doing very little work in reality.
Not the same profile as a house bank of course.

I just don't see the benefit of AGM vs the extra cost. Not saying others might not love them, but we went with two each, 8D sealed lead acid, connected for 24v for our start bank.

 

[slowgoesit]

I have 4 SLA'S for house and and 3 AGM's for thruster,
genny and main engine start (one each). All are heavy and the house batteries are ridiculously hard to access, especially to top the water off as they are in an area with 6" above them. I will be changing the house bank soon and they will not be replaced with SLA.

If by SLA you mean "Sealed Lead Acid", why are you having to top them off with water?!? That's the whole idea of being sealed, isn't it?

 

[Bacchus]

If by SLA you mean "Sealed Lead Acid", why are you having to top them off with water?!? That's the whole idea of being sealed, isn't it?

IMO SLA doesn't even refer to a single batty type but rather a group of batty types and further clarification is required to carry on meaningful info exchanges.
I dont think it's accurate to compare FLA Maint Free, AGM, and Gel Battys... AFAIK these are all "sealed lead acid" battys but can hardly be realistically compared as " apples to apples" for best application, best practices, charging profiles, price, etc.

 

[ranger58sb]

I dont think it's accurate to compare FLA Maint Free, AGM, and Gel Battys... AFAIK these are all "sealed lead acid" battys but can hardly be realistically compared as " apples to apples" for best application, best practices, charging profiles, price, etc.

I think that's all true, but...

Typically I read SLA or Sealed Lead Acid to be taken as synonymous with "Maintenance Free" flooded lead acid (FLA) batteries. Also seems like some brands say "Sealed" and others say "Maintenance Free" -- both referring to unwaterable (?) FLAs.

And when people really mean AGM or Gel instead, they tend to write/say AGM or Gel.

-Chris

 

[PhilPB]

If by SLA you mean "Sealed Lead Acid", why are you having to top them off with water?!? That's the whole idea of being sealed, isn't it?

I misspoke. Flooded Lead Acid batteries. Gotta top off. PITA batteries

 

[SteveK]

I misspoke. Flooded Lead Acid batteries. Gotta top off. PITA batteries

It was a happy day when I replaced the needy FLA batteries. They needed to be checked for fluid level. I now have a watering jug that fills to correct level I have to repurpose or find a new home for.

 

[PhilPB]

It was a happy day when I replaced the needy FLA batteries. They needed to be checked for fluid level. I now have a watering jug that fills to correct level I have to repurpose or find a new home for.

I will be replacing them soon, probably before the house bank dies because they are a pain. My older genius charger can handle anything but lithium.

 

[Bacchus]

IMO SLA doesn't even refer to a single batty type but rather a group of batty types and further clarification is required to carry on meaningful info exchanges.
I dont think it's accurate to compare FLA Maint Free, AGM, and Gel Battys... AFAIK these are all "sealed lead acid" battys but can hardly be realistically compared as " apples to apples" for best application, best practices, charging profiles, price, etc.

I think that's all true, but...

Typically I read SLA or Sealed Lead Acid to be taken as synonymous with "Maintenance Free" flooded lead acid (FLA) batteries. Also seems like some brands say "Sealed" and others say "Maintenance Free" -- both referring to unwaterable (?) FLAs.

And when people really mean AGM or Gel instead, they tend to write/say AGM or Gel.

-Chris

That is one interpretation but I don't think it represents universal agreemen...
This from atbatt.com

"SLA, VLRA, AGM, Is There a Difference?

SLA (Sealed Lead Acid) and VRLA (Valve Regulated Lead Acid) are different acronyms for the same battery. This battery type has the following characteristics: Maintenance-free, leak-proof, position insensitive. Batteries of this kind have a safety vent to release gas in case of excessive internal pressure build up. AGM (Absorbed Glass Mat) refers to a specific type of SLA/VRLA where the electrolyte is absorbed into separators between the plates consisting of sponge like fine glass fiber mats. SLA batteries are divided up into specific subsets of batteries."

Your interpretation isn't necessarily wrong but does point to the need to be more precise when discussing batty types. Others don't always use the same termimology.

 

[ranger58sb]

That is one interpretation but I don't think it represents universal agreemen...
This from atbatt.com

"SLA, VLRA, AGM, Is There a Difference?

SLA (Sealed Lead Acid) and VRLA (Valve Regulated Lead Acid) are different acronyms for the same battery. This battery type has the following characteristics: Maintenance-free, leak-proof, position insensitive. Batteries of this kind have a safety vent to release gas in case of excessive internal pressure build up. AGM (Absorbed Glass Mat) refers to a specific type of SLA/VRLA where the electrolyte is absorbed into separators between the plates consisting of sponge like fine glass fiber mats. SLA batteries are divided up into specific subsets of batteries."

Your interpretation isn't necessarily wrong but does point to the need to be more precise when discussing batty types. Others don't always use the same termimology.

Yep, good points.

-Chris