Domestic batteries for a bear of little brain

[pipemma]

Sorry, it's yet another "which batteries" thread - apologies in advance.

I'm having to change lots of batteries this year - see my bow thruster thread for those.

The underpowered-then-dead bow thruster batteries also drained my domestic bank last autumn They were all only dirt cheap lead-acid batteries which turned out to be a false economy. I'm now looking at something a little more expensive but hopefully more durable and I'd like to get away from lead acid.

We're neither of us sparkies (himself has rudimentary knowledge) so we just want the easy option, that fits into the compartments without major ancillary upgrades or new cabling. So, from reading around here, that means no lithium.

I'm thinking deep-cycle AGM? And I think the domestic bank doesn't need to be dual purpose?

I'm replacing 4 x 125 Ah lead acid; I can get Voltic VDC 120 deep-cycle AGMs (120 Ah) at a reasonable price (bearing in mind I'm also looking at 3 x Optima for 2 x bow thruster and 1 x engine). Any thoughts?

I still have the OEM Cristec battery charger, which we think is a bit rubbish and hardly ever switch on (but charterers could well do), and about 230W of excellent solar panels.

Should I also look at a new battery charger?
I don't want brand new batteries killed by a rubbish charger (as I think also happened with the last set of batteries).


Thanks in advance!

[zaphod]

AGM are still Lead Acid, so I assume you mean you want to get away from Flooded Lead Acid.

You say you rarely use your shore power charger...so the question is how do you make sure your batteries are fully charged? The worst thing you can do is keep conventional Lead Acid batteries at partial charge for long periods. It does permanent damage to them. You are right, the Cristec charger is rubbish. The biggest problem with it is that it automatically switches to float mode after 4hrs regardless of the acceptance rate of the bank. That might be fine on a very small bank, but 4hrs is not enough time to charge a larger bank. Definitely consider a new charger as part of your battery upgrade.

Also invest in a good battery monitor if you don't have one. Being able to monitor current flow in and out of the batteries and State of Charge is very helpful when it comes to taking proper care of the batteries.

In terms of AGM batteries Firefly Carbon Foam batteries are the best you can get. They come at a premium price, but they have significant advantages over regular AGM. Most AGMs can only be discharged to 50% capacity without damaging them. This is a limitation of almost all Lead Acid batteries. Fireflys can be discharged to 20% without damage, so right there you get 30% more capacity for the same size bank. Fireflys will also tolerate being in a partial state of charge for prolonged periods without doing permanent damage. That kind of abuse is the kiss of death for regular Lead Acid batteries.

[Charlie-Bravo]

I would second all that Zaphod has mentioned, and also add, that you might take a jolly close look at the charging algorithm that your solar set up is giving to your batteries. Many solar controls give you a choice of voltages and timescales, using the wrong algorithm might just be giving your batteries a harder time, and shorter life.

CB

[ForGrinsToo]

C-B, Zaphod:

I want to replace my Cristec, but am having difficulty find up-to-date reviews. Victron and Xantrex seem to be industry leaders, and since I have a Victron BMV-712, I lean towards Victron. What are your thoughts?

Thanks,
Geoff

[zaphod]

I went with a Xantrex Freedom Pro XC Charger/inverter which gives me a 100a charger and a 2000w inverter in one unit for less money than a dedicated charger. The only problem is that it only charges a single bank. I don't have a thruster battery to worry about.

There are lots of options out there. Victon is good. The important thing is that it is a smart charger with user configurable profiles.

[vasko]

No need for comments - just a example :

www.photonicuniverse.com/en/catalog/full/162-3000W-12V-low-frequency-pure-sine-wave-off-grid-inverter-peak-power-9000W.html?gclid=EAIaIQobChMIibng9_rm9gIVgu5RCh2BEQMmEAQYASABEgKqkPD_BwE

[pipemma]

Mar 27, 2022 16:21:42 GMT zaphod said:

AGM are still Lead Acid, so I assume you mean you want to get away from Flooded Lead Acid.

You say you rarely use your shore power charger...so the question is how do you make sure your batteries are fully charged? The worst thing you can do is keep conventional Lead Acid batteries at partial charge for long periods. It does permanent damage to them. You are right, the Cristec charger is rubbish. The biggest problem with it is that it automatically switches to float mode after 4hrs regardless of the acceptance rate of the bank. That might be fine on a very small bank, but 4hrs is not enough time to charge a larger bank. Definitely consider a new charger as part of your battery upgrade.

Also invest in a good battery monitor if you don't have one. Being able to monitor current flow in and out of the batteries and State of Charge is very helpful when it comes to taking proper care of the batteries.

In terms of AGM batteries Firefly Carbon Foam batteries are the best you can get. They come at a premium price, but they have significant advantages over regular AGM. Most AGMs can only be discharged to 50% capacity without damaging them. This is a limitation of almost all Lead Acid batteries. Fireflys can be discharged to 20% without damage, so right there you get 30% more capacity for the same size bank. Fireflys will also tolerate being in a partial state of charge for prolonged periods without doing permanent damage. That kind of abuse is the kiss of death for regular Lead Acid batteries.

OK, I take your point about AGM/lead acid, but I think you knew what I meant.

Can't get Firefly in Europe, still less in Greece. In fact I'm struggling to find any mail order suppliers in Greece for any batteries - any ideas?

Do you have a recommendation for a battery monitor? We're currently on the one on the OEM panel, but planning to get a handheld one our mate has (very good but obv not permanent fitting). Are you talking sth like this? www.amazon.de/DollaTek-Programmable-Temperature-Percentage-Indicator/dp/B07JLGRXZS/ref=sr_1_14_sspa?crid=YEG51Y89QYSZ&keywords=agm%2Bbatterie%2B120ah%2Bvarta&qid=1648457720&sprefix=agm%2Bbatterie%2B120ah%2Caps%2C260&sr=8-14-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExNzhTV0xBU1BVT1FIJmVuY3J5cHRlZElkPUEwODgzNDU1MUtCSzFHTVFYRTJYViZlbmNyeXB0ZWRBZElkPUEwNzg0MDgyMTdMT09BU1I0UFI1TyZ3aWRnZXROYW1lPXNwX210ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

Thanks for confirming our thoughts on the battery charger - again any recommendations? Bearing in mind my total budget here is max Fr 2000/€2000 and I have 7 batteries to get (6 of which actually don't exist at the moment as they'd overheated and had to be disposed of).

I would ask for any replies to be in very simple language please (ref my post title) - no idea what a "charging algorithm" is, for example.

[loredo]

pipemma,

I think you need first to know and understand a few things before you decide what battery type is best for you.

AGM's are a great battery but they're very "fragile" /short lived if not charged right.

The thing that has been learned in real world usage about them is that they NEED to be charged to 100% frequently!

Not charging them to 100% kills them in very short time.

This is where the problems start.

The battery charger needs to have the right "charging profile"  (often referred to as Algorithm or also IoI ) and in addition has

to be able to be set to certain voltages.

To help you understand (I'll try to keep it simple). 

The "Smart" chargers do at least three different steps during charging:

Bulk / Absorption /  Float.

Bulk = Is the step where most of the charge is restored into the battery.  In poor words as much power (ampere) as possible until

the battery reaches a certain voltage.  Once that voltage is reached, switch over to the next charging step.

Absorption = this is the critical step to get the battery to full charge.  With way less ampere than in bulk bring up the battery to 14.4 to 14.7 volt. This voltage is critical and depends upon the brand of the AGM's!  Not all AGM batteries are created the same!  You need to get the data sheet for the battery you're picking and the set up the battery charger with exactly the voltage required.   

Thus, if you want the AGM's to last, you need a battery charger that can be setup for your batteries. Not many out there who can

really do that.  Also worth consideration is the fact that then taller the battery bank, then longer becomes the absorption stage.

A boat frequently on shore power might be fine. Running the generator endless hours in a bay just to make the batteries

happy...   This is one reason (amongst others) for switching to lithium batteries.  Yet they come with their own set of problems.

Float = once the battery charger has reached the right voltage in absorption it'll switch over to float where it basically stays

at a fixed voltage and provides the power needed by the various appliances in the boat without using too much of the battery

power (If any at all).

You said something about charterers.  Do you think a charterer will care to take care about the AGM batteries?

Given the price tag for the AGM / Battery Charger / MPPT and so on, is it a good investment?

Sure, if charged right, the AGM battery do last a long time but they cost also a lot more than ordinary flooded batteries.

In addition they require attention to the charging during their use.

Now, ask yourself : do I really want the AGM chemistry?

Maybe, monetary wise, it makes more sense to just stay with flooded batteries and change them every 2-3 years?

Loredo

 

[ianpowolny]

Pippa,

We bought these last year: en.wccsolar.net/product-page/bateria-agm-plusenergy-tp12-150-12v-100-150ah

Good people to talk to. They’ll tell you if they can deliver to Greece. Note the 150ah is based on C100 so I’ve assumed a C20 rating of 115ah.

Get in touch with Rory Stewart through the Jeanneau page on Facebook. He’s changed his bow thruster batteries to some kind of lorry battery. He’s pleased with them.

On Affinity we’ll change the bow thruster batteries to cheaper that Red Top AGMs this year.

Ian

[zaphod]

Mar 28, 2022 9:05:24 GMT pipemma said:

Mar 27, 2022 16:21:42 GMT zaphod said:

AGM are still Lead Acid, so I assume you mean you want to get away from Flooded Lead Acid.

You say you rarely use your shore power charger...so the question is how do you make sure your batteries are fully charged? The worst thing you can do is keep conventional Lead Acid batteries at partial charge for long periods. It does permanent damage to them. You are right, the Cristec charger is rubbish. The biggest problem with it is that it automatically switches to float mode after 4hrs regardless of the acceptance rate of the bank. That might be fine on a very small bank, but 4hrs is not enough time to charge a larger bank. Definitely consider a new charger as part of your battery upgrade.

Also invest in a good battery monitor if you don't have one. Being able to monitor current flow in and out of the batteries and State of Charge is very helpful when it comes to taking proper care of the batteries.

In terms of AGM batteries Firefly Carbon Foam batteries are the best you can get. They come at a premium price, but they have significant advantages over regular AGM. Most AGMs can only be discharged to 50% capacity without damaging them. This is a limitation of almost all Lead Acid batteries. Fireflys can be discharged to 20% without damage, so right there you get 30% more capacity for the same size bank. Fireflys will also tolerate being in a partial state of charge for prolonged periods without doing permanent damage. That kind of abuse is the kiss of death for regular Lead Acid batteries.

OK, I take your point about AGM/lead acid, but I think you knew what I meant.

Can't get Firefly in Europe, still less in Greece. In fact I'm struggling to find any mail order suppliers in Greece for any batteries - any ideas?

Do you have a recommendation for a battery monitor? We're currently on the one on the OEM panel, but planning to get a handheld one our mate has (very good but obv not permanent fitting). Are you talking sth like this? www.amazon.de/DollaTek-Programmable-Temperature-Percentage-Indicator/dp/B07JLGRXZS/ref=sr_1_14_sspa?crid=YEG51Y89QYSZ&keywords=agm%2Bbatterie%2B120ah%2Bvarta&qid=1648457720&sprefix=agm%2Bbatterie%2B120ah%2Caps%2C260&sr=8-14-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExNzhTV0xBU1BVT1FIJmVuY3J5cHRlZElkPUEwODgzNDU1MUtCSzFHTVFYRTJYViZlbmNyeXB0ZWRBZElkPUEwNzg0MDgyMTdMT09BU1I0UFI1TyZ3aWRnZXROYW1lPXNwX210ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

Thanks for confirming our thoughts on the battery charger - again any recommendations? Bearing in mind my total budget here is max Fr 2000/€2000 and I have 7 batteries to get (6 of which actually don't exist at the moment as they'd overheated and had to be disposed of).

I would ask for any replies to be in very simple language please (ref my post title) - no idea what a "charging algorithm" is, for example.

The Victron BMV712 battery monitor is quite popular and that's the one I have on my boat. It is nice because you can connect to your phone via Bluetooth, and using their app it gives you a lot of useful information. It will track amps in, amps out, battery Temps, state of charge, and give you historical data such as deepest discharge, time since last full charge etc.

It is unfortunate that you can't get Fireflys where you are, because they are the ones that are more likely to tolerate the abuse that charters are likely to put them to. Laredo has a point; you should consider whether you want to invest in high end AGMs only to have charter users destroy them in short order. You may want to consider quality FLAs instead.

You may also want to get quotes on a professionally installed Lithium system so you at least know what that option costs.

In terms of chargers, most marine multi stage battery chargers have user defined battery profiles these days. Victron, Xantrex and Mastervolt are all good brands but there are others out there. It depends on what products you can get in your area.

[pipemma]

Mar 28, 2022 11:33:39 GMT ianpowolny said:

Pippa,

We bought these last year: en.wccsolar.net/product-page/bateria-agm-plusenergy-tp12-150-12v-100-150ah

Good people to talk to. They’ll tell you if they can deliver to Greece. Note the 150ah is based on C100 so I’ve assumed a C20 rating of 115ah.

Get in touch with Rory Stewart through the Jeanneau page on Facebook. He’s changed his bow thruster batteries to some kind of lorry battery. He’s pleased with them.

On Affinity we’ll change the bow thruster batteries to cheaper that Red Top AGMs this year.

Ian

Hi Ian

I always like it when you reply, since Affinity and Cloud Nine are effectively sister ships

Tell me, are those batteries exclusively (or specifically) designed for operation with solar panels (we do have 230+W of solar)? Does it add an extra factor into the situation? e.g. specific charger to charge them from shore power? Those batteries look like excellent bang for buck, but I wonder what information I'm missing - if it sounds too good to be true....

Thanks
Emma

[dbostrom]

Seconding/emphasizing loredo's point about absorption, which unfortunately involves guesswork on the part of any charging algorithm given real-world limitations on what the charger's state of information is against what amount of AH depletion it's restoring to the battery. In a laboratory some hints can be drawn from voltage/amperage curves as the battery is charged, but in the real world the precision of measurements required for this is not available, not least because of perturbances causing terminal voltage of batteries to waver etc. So the charger is left with absorption phase consisting of  "I'll put this number of AH in, but I really don't know what deficit I'm trying to replenish."  

The out-of-the-box absorb phase guessing tends to err on the short side. A charger with configuration options for absorb charging allows you to supplement generalized assumptions with data based on your actual usage profile of your batteries. When we plug in local numbers and apply them, the result tends to be "configure absorption phase longer." 

This is all "let's refine the walking beam steam engine" when we've moved on to having triple expansion piston steam engines available. As soon as possible ditch lead acid of any kind and move on to lithium iron phosphate, where all the wretched by-guess-and-by-golly of lead acid becomes a thing in a museum.  For domestic, anyway; starter/windlass/thruster lead acids are much easier to manage as their depletion is typically so scanty. 

[ianf]

Can't get Firefly in Europe, still less in Greece. In fact I'm struggling to find any mail order suppliers in Greece for any batteries - any ideas?

Have you tried the chandlery in Nidri? I was in there last year and they had a large selection of batteries and I bet if they didn't have what you wanted they could get it.

[pipemma]

Just coming back to this.... following your various recommendations, I've ordered the Victron Phoenix Smart IP43 3-bank battery charger and the BMV-712 Smart from our local guys (who supplied all my Raymarine kit and our solar panels/MPPT) who will also install it them, and I will ask them to check the entire system of monitor/charger/3 x battery banks/solar & MPPT in the process.

Our local guys quoted me for Victron batteries, but they're silly money. I looked at the ones ianpowolny had bought and they looked really promising so I contacted the supplier. However, after replying quickly saying they could deliver to Greece by the end of the month and cost would depend on the delivery address, it's been radio silence since re shipping quote and whether they actually have them in stock - this despite 2 follow-up mails and a phone call. Time's too tight now, I fear.

After a lot more searching, I've found these batteries from a Greek supplier:

www.thebatteryshop.gr/mpataries-vathias-ekfortisis/mpataria-sunlight-115s-accuforce-1

and here's the manufacturer's website:
www.systems-sunlight.com/product/reserve-power/accuforce-s/

I don't know the brand, but they seem to be a similar type to the ones ianpowolny bought, they're manufactured in Greece and they're in stock (always a bonus ), so whilst I'm going to sleep on it for another day or so, I think I'm going to take a punt on these as a happy medium.

4 x 115 Ah is only a 40 Ah reduction across the bank on the 4 x 125 Ah no-name FLA truck batteries we had before, and still a 60 Ah increase on the 4 x 100 Ah that the old set replaced.

[moonshadow]

I don’t want to make this complicated beyond what you want to explore. But I can’t read Greek but I would agree that if you don’t want to change your charging setup then staying with an AGM or SLA set of batteries makes sense. Especially if you will be chartering the boat a fair amount. Any of the new battery types, lithium or Firefly, would likely require some additional changes to your alternator and charging system so you don’t wear out belts fast or burn an alternator.
For me I changed to the firefly and added a new regulator etc and didn’t find it a big problem. And much better performance. But given the lack of choices you face and what sounds like wanting to keep changes minimal I think you are making a good decision to stick with something that has generally been working.

[pipemma]

Apr 15, 2022 23:26:39 GMT moonshadow said:

I don’t want to make this complicated beyond what you want to explore. But I can’t read Greek but I would agree that if you don’t want to change your charging setup then staying with an AGM or SLA set of batteries makes sense. Especially if you will be chartering the boat a fair amount. Any of the new battery types, lithium or Firefly, would likely require some additional changes to your alternator and charging system so you don’t wear out belts fast or burn an alternator.
For me I changed to the firefly and added a new regulator etc and didn’t find it a big problem. And much better performance. But given the lack of choices you face and what sounds like wanting to keep changes minimal I think you are making a good decision to stick with something that has generally been working.

Thank you for confirming my thought processes.
FWIW my Greek is negligible, but if you open the site in Chrome, it will prompt you if you want to translate it (Google Translate). I may be a professional translator, and much prefer DeepL (Pro), but Chrome with Translate is useful even for me