Help w/ battery challenge

[MichaelB1969]

As usual, we here at TF tend to throw a lot of ideas around that seem peripheral to your original question (where to get batteries to fit?).

There is nothing wrong with just finding some batteries that will fit into your easily used space (ie without much modification) and call it good. The other thing to at least think about is what you would want to eventually have as an electrical setup.

-I assume you have a separate start batteries that are fed by your alternators? You may want to consider having the alternators charge the house bank and have DC to DC chargers that charge the start batteries.
-Figure out how much you need in terms of Ah capacity for your use.
-Add some type of SOC meter (that way you won't go below 50% SOC on your batteries making them last longer). You can also set them to have the genset start automagically if a given SOC is reached.
-Add the recommended fuse for the battery wiring while you are at it.

Lots of stuff to consider but if you know what you want to do eventually, then you can move in that direction piece by piece, starting with the new house bank batteries.

Thanks for the guidance. Seems like the SOC meter is a wise investment up front if I go with AGM batteries.

I think I have 9 batteries total, all AGM except for the two house, as follows:

1 battery for starboard engine
1 battery for port engine
1 battery for generator
2 batteries for stern thruster
2 batteries for bow thruster
2 batteries for house

I am not 100% sure, but I think the alternators charge the house batteries now. I believe while underway (without generator on) I can flip the battery charger switch to "on" and it lights up red.

As for the fuse for the battery wiring, not sure what this is for, and I wonder if the boat might already have it as there are a bunch of fuses that I believe the batteries are wired to.

Goodness, I have a lot to learn...

 

[dhays]

Goodness, I have a lot to learn...

You and me both! My attitude is that I don't have to learn it all at once. I just chip away at the great massive stone of my ignorance and it gradually gets smaller over time.

Taking the time to figure out how all those battery banks are charged would be a good weekend's endeavor. If you have an original schematic from the manufacturer it would give you a head start, but keep in mind that things could easily have been changed since then. On my boat, which is only a single, it took me some time to figure out how the batteries were setup and configured.

 

[MichaelB1969]

You and me both! My attitude is that I don't have to learn it all at once. I just chip away at the great massive stone of my ignorance and it gradually gets smaller over time.

Taking the time to figure out how all those battery banks are charged would be a good weekend's endeavor. If you have an original schematic from the manufacturer it would give you a head start, but keep in mind that things could easily have been changed since then. On my boat, which is only a single, it took me some time to figure out how the batteries were setup and configured.

I've been following your engine issue, and wrote how amazed I was at how you kept your composure. I am sure that experience will chip away quite a bit of that massive stone you referenced!

My boat does have a manual with the schematic, and up to now I've been focused on more practical content, such as how to turn things on and off.

But now is probably a good time to study those schematics! Thanks for the reminder. Doubt anything has changed since the boat is a 2014 model and the prior owner didn't make any changes.

Best,
Mike

 

[john61ct]

I will be using either the generator if out at an anchorage or shore power when at the dock. No solar or anything else.

Then your bank won't be getting to 100% full when you are away from shore, that takes 4+ hours and silly to burn dino juice that long every day.

If you run the genny in the AM to get the bank to 80-85%, then you just need enough panels to carry the fridge and they'll end up topping up the bank by end of the day.

Or look at Firefly Oasis, the only lead batt doesn't die an early death from partial SoC abuse, but G31 only and $500+ per 100AH.

Or like I said, buy the cheapest (Duracell GC2) and accept doing so much more frequently than if you got them to full every day.

IF you mostly get back on shore every night then that may be every three years, NBD.

 

[MichaelB1969]

Then your bank won't be getting to 100% full when you are away from shore, that takes 4+ hours and silly to burn dino juice that long every day.

If you run the genny in the AM to get the bank to 80-85%, then you just need enough panels to carry the fridge and they'll end up topping up the bank by end of the day.

Or look at Firefly Oasis, the only lead batt doesn't die an early death from partial SoC abuse, but G31 only and $500+ per 100AH.

Or like I said, buy the cheapest (Duracell GC2) and accept doing so much more frequently than if you got them to full every day.

IF you mostly get back on shore every night then that may be every three years, NBD.

I'll check out the options you mentioned. Thanks. I'd say I'd be away from shore 1 night on occasion. But typically we return each night.

 

[john61ct]

You may want to consider having the alternators charge the house bank and have DC to DC chargers that charge the start batteries.

Yes +1 all charge sources should go to House direct, proper heavy gauge wires and fuse(s).

That means an Echo Charger to the Starter batt(s) is good enough, cheaper than a DCDC charger, which is usually overkill in this use case.

If leaving the Alt output to Starter, then a quality high-amp combiner (ACR/VSR) is a good solution.

DCDC charger should only be needed if the House bank chemistry requires a different voltage, or a long-run voltage drop is unavoidable.

 

[john61ct]

Given that I just paid $3,500 for my bimini top, $2,500 for my Volvo service, $2,700 for my life raft and I am about to pay who knows what to repair a bent shaft (courtesy of the previous owner), I think this (most capacity in available space) is where my head is at. Not saying it is the best long-term approach, but it's all I have the appetite for at this point in time.

Just note you should buy your House bank all at once, same model batts same factory run.

Adding new cells to an already aged set will cause the bank as a whole to perform as per the weakest link.

Not a critical concern, but something to keep in mind.

 

[dhays]

Yes +1 all charge sources should go to House direct, proper heavy gauge wires and fuse(s).

That means an Echo Charger to the Starter batt(s) is good enough, cheaper than a DCDC charger, which is usually overkill in this use case.

Yup. An Exhibition charger is what I'm using for my start battery now. Cheap, easy, reliable.

For the OP it will be interesting to see how it is setup. Maybe an ACR since his boat is a 2014 and all AGM batteries.

I don't think the occasional weekend of only getting up to 85% SOC should be an issue for him. It isn't like the full time cruisers that rarely get to shore power.

 

[john61ct]

I'll check out the options you mentioned. Thanks. I'd say I'd be away from shore 1 night on occasion. But typically we return each night.

Well then don't worry about that side, as long as the bank is sized conservatively vs the daily usage, a "cycle" can be two days.

And stinkpots do have alts pumping amps for a lot more hours per day compared to many cruising sailboats, that buys a lot of leeway.

 

[john61ct]

By the way, when you are planning a full electrical redesign, all those separate batteries is a lot of expensive and heavy dead lead. Starting is actually a miniscule load compared to other uses, and you can still get security/redundancy much more efficiently than that.

IMO plan on one big House bank with some heavy-amp wiring, a single smaller Reserve/Starting bank, and switches to run loads off either as needed.

Maybe get ready to transition toward that as each battery needs replacing.

 

[ranger58sb]

Given that I just paid $3,500 for my bimini top, $2,500 for my Volvo service, $2,700 for my life raft and I am about to pay who knows what to repair a bent shaft (courtesy of the previous owner), I think this (most capacity in available space) is where my head is at. Not saying it is the best long-term approach, but it's all I have the appetite for at this point in time.

Yep, sometimes easiest to solve "adequately" for now, and get on with boating.

I will check out the SmartGauge, thanks. As for the charge sources, I will be using either the generator if out at an anchorage or shore power when at the dock. No solar or anything else.

A minor comment here, just in case you didn't yet fully recognize the issue about charging sources. Yes, you would be using the genset sometimes, but there's another intermediate system in between genset and batteries: the battery charger (sometimes called converter, somtimes combined with an inverter). Genset capability is important to know about, of course, but the charger capability becomes germane reasonably quickly. Small charger (e.g., 20-amp) and big battery bank, not so great. Big charger and big battery bank, usually better, depending. That where all the discussion about .1C or .2C or whatever comes into play.

Thanks for the guidance. Seems like the SOC meter is a wise investment up front if I go with AGM batteries.

I'm one of the contrarians around here who doesn't bother to use a SOC meter, and that's with AGM batteries but would have likely been with whatever batteries I happen to have.

We're partly influenced by electric cooking and water heater. We're also partly influenced by our overall battery capacity, which was 600-Ah until last week, and is now 740-Ah. At anchor, we have to use the genset to cook, so while we're at it we charge batteries and make hot water. That usually means morning and evening genset cooking (and charging) sessions... which in turn means we rarely draw batteries down enough to really care much about SOC.

Voltage, which others will correctly state isn't a perfect guide, has been quite sufficient for us.

YMMV but... (wait for it...)

I'll check out the options you mentioned. Thanks. I'd say I'd be away from shore 1 night on occasion. But typically we return each night.

This pretty much means you may not have to care much about exact SOC either. Within reason. And modified by your experience going forward.

-Chris

 

[FF]

"At anchor, we have to use the genset to cook, so while we're at it we charge batteries and make hot water. That usually means morning and evening genset cooking (and charging) sessions... which in turn means we rarely draw batteries down enough to really care much about SOC."


True it would be unlikely to kill the batt set O'nite , but do you think it is being recharged enough daily to reach 100%?

If not, you may join the always under charged group of cruisers and have shorter service life from the batt set.

Multiple daily hydrometer readings does work for monitoring , but most folks find a SoC meter much less a PIA.

 

[john61ct]

Very true. With decent loads on the hook, unless you're literally motoring many hours every day you're never getting a bank back to 100% on dino juice alone.

Heading back to shore charging soon, then no problem

Otherwise even a little solar will pay for itself in bank longevity.

And without accurate SoC you'd never know.

 

[MichaelB1969]

ranger 42c, thanks for the clarification on the charger. Good point. I did some homework and it looks like my best best is to go with the Victron Energy AGM. Either (2) 230Ah units or (4) 100Ah units. The 230Ah might "just" fit without any modification while the 100Ah will definitely fit. Either way I'd be going from a house bank at 280Ah to between 400Ah - 460Ah, so potentially double. Might need to look at the charger.

By the way, these are Victron "Super Cycle" which according to Victron are designed to be more forgiving of significant or complete discharge.

https://www.victronenergy.com/upload/documents/Datasheet-AGM-Super-Cycle-battery-EN.pdf

 

[john61ct]

Victron is a fine vendor for most product categories, obviously initial cost is not a big deal for you, I'm sure their batts are great value long-term, any idea who the actual mfg is?

A smaller number of large batteries is better than many small ones.

Down the road, look at their larger "kombi" inverter/charger units with auto switchover, nice kit there.

Also they are an industry leader for LiFePO4 banks w/ integrated BMS.

Just make sure with a pricy bank like that, do get good battery monitoring in place, and even if you "can" allow them to go below 50%, you should really do so rarely, ideally in emergencies only with lead.

I'm sure you can get their "lifetime cycles vs DoD" charts and see how shallower cycling buys you many more years of service.

I **highly** recommend Bruce at Ocean Planet as a Victron dealer, at least get a quote from him. IMO for kit like this it's worth paying a bit more for truly expert support.

 

[MichaelB1969]

Victron is a fine vendor for most product categories, obviously initial cost is not a big deal for you, I'm sure their batts are great value long-term, any idea who the actual mfg is?

A smaller number of large batteries is better than many small ones.

Down the road, look at their larger "kombi" inverter/charger units with auto switchover, nice kit there.

Also they are an industry leader for LiFePO4 banks w/ integrated BMS.

Just make sure with a pricy bank like that, do get good battery monitoring in place, and even if you "can" allow them to go below 50%, you should really do so rarely, ideally in emergencies only with lead.

I'm sure you can get their "lifetime cycles vs DoD" charts and see how shallower cycling buys you many more years of service.

I **highly** recommend Bruce at Ocean Planet as a Victron dealer, at least get a quote from him. IMO for kit like this it's worth paying a bit more for truly expert support.

Not sure who makes their batteries.

All good advice. Yeah, my strategy would be to keep them above 50% but nice to know if I screw up there is a bit more margin for error in terms of longevity.

I can check with Bruce. Thx!

 

[john61ct]

Ask him, he may not be allowed to say

 

[ranger58sb]

"At anchor, we have to use the genset to cook, so while we're at it we charge batteries and make hot water. That usually means morning and evening genset cooking (and charging) sessions... which in turn means we rarely draw batteries down enough to really care much about SOC."


True it would be unlikely to kill the batt set O'nite , but do you think it is being recharged enough daily to reach 100%?

If not, you may join the always under charged group of cruisers and have shorter service life from the batt set.

Multiple daily hydrometer readings does work for monitoring , but most folks find a SoC meter much less a PIA.

Very true. With decent loads on the hook, unless you're literally motoring many hours every day you're never getting a bank back to 100% on dino juice alone.

Heading back to shore charging soon, then no problem

Otherwise even a little solar will pay for itself in bank longevity.

And without accurate SoC you'd never know.

Good points, and no, we can't usually get our batteries back up to 100% on a daily basis when we're out. OTOH, we rarely anchor out for more than a week at a time, and more often we're in and out of marinas every third or fourth day or so if we're on a more extended trip. IOW, our charging regime seems to have been "good enough," given lifespan on the AGM bank we just replaced.

Certainly wouldn't turn down some solar augmentation, but that hasn't bubbled up to the top of my wallet yet.

Can't use a hydrometer anyway, given our sealed batteries, but I wouldn't turn down a SOC monitor either, for that matter. OTOH, it hasn't become important enough -- for our usage pattern -- to be obviously warranted.

And that leads to part of my point: Yes, I'd "know" better with a SOC meter, but there's not much I could do about it (without solar). Or maybe I could run the genset 3x/day instead of 2x... but we're not likely doing that. IOW, the additional info might be interesting, but probably wouldn't make much difference in the way we operate the boat.

Not a recommendation, just an observation...

-Chris

 

[mbevins]

I have a complete Victron system, combination inverter and telecom batteries, l have a 275 amp Balmar alternator and their smart gauge.
Worth every penny.
The Telecom allow me to put the equivalent of four 8Ds in the space of two.
For me that was whole project.

 

[ranger58sb]

Very true. With decent loads on the hook, unless you're literally motoring many hours every day you're never getting a bank back to 100% on dino juice alone.

And something I didn't include in my earlier description of our normal charging regimen:

We sometimes do run with genset and ACs on while underway, actually often in July and August, so we can keep the critter cool inside in the AC... and so the saloon etc. isn't absolutely sweltering (from lots of glass) when we finally get someplace, either anchorage or marina.

And then if it's a sweltering anchorage, again especially in July and August around here, we'll leave the genset and ACs running until outside temps start to come down for the evening.

In those instances, the alternators and chargers are both able to keep the battery charge level pretty high... so yet another reason why more info from something like a SOC meter probably wouldn't cause much difference in our routine.

-Chris

 

[FlyWright]

I agree with Chris that it depends on your routine...today and tomorrow. Day cruises and day fishing trips? No need for a big bank. If you think you might want to stay out on the hook for 3 days or more with minimal main or genset use, a bigger bank is more important.

Often, our use changes from that we first imagined with a trawler. A larger bank provides future options you might not have otherwise.

I have a complete Victron system, combination inverter and telecom batteries, l have a 275 amp Balmar alternator and their smart gauge.
Worth every penny.
The Telecom allow me to put the equivalent of four 8Ds in the space of two.
For me that was whole project.

That's the way to look at an electrical system! It covers the whole enchilada spec'd from top to bottom.

 

[Gordon J]

The batteries from energy 1 come in varies sizes. Take a look at the dimensions. These are AGM batteries and can be stored in any position except upside down. These are not standard sizes. I was able to replace two 4-D batteries with three of their 4-D equivalents in last boat.

Gordon

Gordon

 

[FF]

"our charging regime seems to have been "good enough," given lifespan on the AGM bank we just replaced."

AGM can usually be charged at a higher rate than WLA , so the next time anything in the charging system dies an upgrade might be easy?

 

[ranger58sb]

"our charging regime seems to have been "good enough," given lifespan on the AGM bank we just replaced."

AGM can usually be charged at a higher rate than WLA , so the next time anything in the charging system dies an upgrade might be easy?

Yep, exactly. I've already made some incremental improvements in charging capability along the way, anyway, since I had increased battery capacity a bit when I switched over to the first AGMs starting in 2006.

One, I took the genset battery off the original 40-amp 3-stage charger (genset alternator works sufficiently well, for its own battery). A minor improvement, and actually more focused on better balancing bank loads.

Then I removed one of the remaining start/house combo banks from that original charger, too, and gave it its own 70-amp inverter/charger. That bank was just increased from 300-Ah to 440-Ah, so the charge rate still probably isn't optimal, but the new 2000W PSW/70-Amp unit was otherwise suited to our needs.

And now the original 40-amp charger only has a single 300-Ah bank to service. It's not perfect, but works, given our usage/charging patterns. (Mostly it worked OK for the two 300-Ah banks for about 12 years.)

I reckon when the original charger craps out, or for some reason a bundle of unclaimed cash shows up, I can replace it then with a higher-amperage unit

-Chris

 

[john61ct]

def moving in the right directions

 

[MichaelB1969]

I need to check my charger capacity. Any idea what charge rate is optimal if the charger is connected to a house bank with between 400 - 460Ah?

 

[dhays]

I need to check my charger capacity. Any idea what charge rate is optimal if the charger is connected to a house bank with between 400 - 460Ah?

That is dependent on the type and manufacturer of the battery. You can usually find that information from the company website, or simply an email to them. When I asked US Batteries about their AGMs, they said they can take a charge up to 30% of the Ah capacity. My bank is 780 Ah, so that would be up to about 225 amps. My charger only charges at 125amps max, so I set it at max.

Lifeline claims some ungodly high CAR, up to 5x Ah capacity if I recall correctly. So those will take almost as many amps as you can throw at them. That really speeds up Bulk charging and is certainly helpful in the early phases of Absorb phase.

 

[mbevins]

That's the way to look at an electrical system! It covers the whole enchilada spec'd from top to bottom.

There are advantages to using the same MFG for both the batteries and the inverter/charger. They are designed to work with each other and there's one point of responsibility if there is an issue with any part of the system. If Victron had an alternator I would have given it serious thought as well, but they don't. I'm very happy with the Balmar equipment as well.

 

[john61ct]

I need to check my charger capacity. Any idea what charge rate is optimal if the charger is connected to a house bank with between 400 - 460Ah?

Call the mfg and ask the CAR spec, Charge Acceptance Rate.

.15-.25C for low-end FLA, .3-.6C or higher for many AGM, some chemistries can go well over 100%.

They sometimes spec a "maximum" rate lower than what it actually is, just legal CYA IMO, at least with lead you can offer more than the bank will accept no harm done as long as your connections, wiring gauge etc are robust.