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Newbie to AmpereTime 300 Ahr batteries. What should I know?

curtism

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Jan 14, 2021
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I just bought two of these for my sailboat after much deliberation. From the tear down video they seem very well made and at $0.22 and Ahr they're a good deal. I know they don't have the low temp cut-off, but I'm in Grenada and am never going north of say 25 degree Latitude. So, it's not needed.

The rest of my system:
-580 watts solar fed through a BlueSky 3000 controller
-D400+ windgen
-8.5 kwh Kohler genset fed through a brand new Victron Multiplus charger/inverter 120 amp/3000 watt

I plan to set these in parallel as my boat is a 12 volt system for the 600 Ahr pool.

Now my questions:
1. What do I need to do as soon as I get these batteries? I've read about an initial charge and such. I can go to a dock for a couple days for shore power in order to do what needs to be done.

2. Placement. The only place I can put these things is where the current batteries are. They are setup in the engine/genset compartment. Is heat going to be an issue? Currently the batteries do get up near 100 degrees F. Is this okay for lifepo?

3. My current batteries are Duracell AGMs that never were what they should have been. I did the initial charge on them at the doc before using them, but they just have never held up. The store down here would not take them back because they would pass a load test. However, I had an electrician look, we did a capacity test and they were never the 245 Ahrs as advertised. They continually got weaker and weaker until now I am lucky if they make it through the night.
Being in the Caribbean sucks as warranties are a difficult thing. Even Duracell refuses to stand behind their 12 month free replacement program because of where I am. I've called East-Penn/Deka (the manufacturer), and they want to avoid blame also. However, the claim representative said he will see what he can do for me.
Basically, I want to do everything right so I don't have any issues. Those AGMs were $2300 (the Caribbean pirates do exist) and that hurts.

Thanks for reading
 
I just bought two of these for my sailboat after much deliberation. From the tear down video they seem very well made and at $0.22 and Ahr they're a good deal. I know they don't have the low temp cut-off, but I'm in Grenada and am never going north of say 25 degree Latitude. So, it's not needed.

The rest of my system:
-580 watts solar fed through a BlueSky 3000 controller
-D400+ windgen
-8.5 kwh Kohler genset fed through a brand new Victron Multiplus charger/inverter 120 amp/3000 watt

I plan to set these in parallel as my boat is a 12 volt system for the 600 Ahr pool.

Now my questions:
1. What do I need to do as soon as I get these batteries? I've read about an initial charge and such. I can go to a dock for a couple days for shore power in order to do what needs to be done.

Charge to max of 14.6V
Float to a max of 13.6V for regular use. If it is going to be on float for a long time, 13.2V, as you don't want to store them at a high state of charge for extended periods.

NO equalization. Ever.
NO temperature compensation. Ever.

Avoid discharging below 12V

Get a quality battery monitor that counts current. Since you're already on Victron, a smartshunt or BMV-712 is ideal.

2. Placement. The only place I can put these things is where the current batteries are. They are setup in the engine/genset compartment. Is heat going to be an issue? Currently the batteries do get up near 100 degrees F. Is this okay for lifepo?

It's not optimal, but you have to live with it. LFP is more tolerant of 100°F than AGM.

3. My current batteries are Duracell AGMs that never were what they should have been. I did the initial charge on them at the doc before using them, but they just have never held up. The store down here would not take them back because they would pass a load test. However, I had an electrician look, we did a capacity test and they were never the 245 Ahrs as advertised. They continually got weaker and weaker until now I am lucky if they make it through the night.

245Ah is likely a C20 rating, which means you need to discharge it at at 12.25A for 20 hours to confirm capacity. If you discharged it at a higher rate, you'll never get 245Ah. 580W of solar for 490Ah of batteries is pretty marginal considering that your panels are likely subject to partial or complete shading, and you rarely get peak current - which is barely at the minimum of what is needed for 490Ah of batteries.

Since I don't see a battery monitor, you can't confidently say that you didn't run these down below 50% SoC, nor did you necessarily always get them charged to true 100% (100% on a charge controller display is rarely true 100%). Both of which may result in severely reduced life. Nor can you confidently say that you always charged them within acceptable current limits.

Lead-acid requires temperature compensation during charging. If you were charging these batteries at 100°F w/o temperature compensation active, you fried them. When at elevated temperature, the absorption voltage MUST be reduced - about 0.5V at 100°F for a typical battery. If the batteries say to charge at 14.4V, you need to charge them at 13.9V @ 100°F. Charging at 14.4V @ 100°F will damage them.

This applies to the float voltage as well.

AGM batteries also have shorter service life than properly maintained flooded batteries. 4 years is a pretty good run for deep cycle AGM batteries charged daily to 100% and discharged to 50%. Abuse them, and they can have dramatically shorter life.

Likely issues I see in the info provided:
1) you have over utilized your batteries depleting them below 50% SoC (using more power than your panels can provide in a day).
2) failing to consistently hit true 100% SoC on a daily basis related to #1.
3) Insufficient peak charge current to properly charge (low currents can induce sulfation)
4) charged at excessively high voltage during high temperature conditions causing degradation.

I know you didn't ask for this assessment, and you're obviously chapped about the $ situation; however, I personally find comfort in seeing that I may have responsibility in an undesirable outcome and see that I have control over future situations. I see the loss as tuition to learn something I didn't know.

Given the questions you're asking, it's clear you want no repeats. :)
 
Charge to max of 14.6V
Float to a max of 13.6V for regular use. If it is going to be on float for a long time, 13.2V, as you don't want to store them at a high state of charge for extended periods.

NO equalization. Ever.
NO temperature compensation. Ever.

Avoid discharging below 12V

Get a quality battery monitor that counts current. Since you're already on Victron, a smartshunt or BMV-712 is ideal.



It's not optimal, but you have to live with it. LFP is more tolerant of 100°F than AGM.



245Ah is likely a C20 rating, which means you need to discharge it at at 12.25A for 20 hours to confirm capacity. If you discharged it at a higher rate, you'll never get 245Ah. 580W of solar for 490Ah of batteries is pretty marginal considering that your panels are likely subject to partial or complete shading, and you rarely get peak current - which is barely at the minimum of what is needed for 490Ah of batteries.

Since I don't see a battery monitor, you can't confidently say that you didn't run these down below 50% SoC, nor did you necessarily always get them charged to true 100% (100% on a charge controller display is rarely true 100%). Both of which may result in severely reduced life. Nor can you confidently say that you always charged them within acceptable current limits.

Lead-acid requires temperature compensation during charging. If you were charging these batteries at 100°F w/o temperature compensation active, you fried them. When at elevated temperature, the absorption voltage MUST be reduced - about 0.5V at 100°F for a typical battery. If the batteries say to charge at 14.4V, you need to charge them at 13.9V @ 100°F. Charging at 14.4V @ 100°F will damage them.

This applies to the float voltage as well.

AGM batteries also have shorter service life than properly maintained flooded batteries. 4 years is a pretty good run for deep cycle AGM batteries charged daily to 100% and discharged to 50%. Abuse them, and they can have dramatically shorter life.

Likely issues I see in the info provided:
1) you have over utilized your batteries depleting them below 50% SoC (using more power than your panels can provide in a day).
2) failing to consistently hit true 100% SoC on a daily basis related to #1.
3) Insufficient peak charge current to properly charge (low currents can induce sulfation)
4) charged at excessively high voltage during high temperature conditions causing degradation.

I know you didn't ask for this assessment, and you're obviously chapped about the $ situation; however, I personally find comfort in seeing that I may have responsibility in an undesirable outcome and see that I have control over future situations. I see the loss as tuition to learn something I didn't know.

Given the questions you're asking, it's clear you want no repeats. :)
Fantastic response. Thank you as your information is exactly what I was looking for.

One thing though. I didn't mention I do have the victton monitor you talk about along with the temp sensor and everything is set to compensate for that. I had the local Victron tech install all this

Before the Victron, I had a Heart 20 with the Xantrex Link 2000. Had the temp sensor and temp compensation then too. When I got the AGMs, I had an electrician come aboard and help me make sure everything was set properly.

You are right that I didn't charge the AGMs to 100 percent everyday (I actually had 780 watts of solar until recently due to a docking accident). There were plenty of cloudy days bit very windy that I just didn't want to run the loud and hot genset and figured screw it. These were days with wind over 20 knots at anchor (I like anchoring in windy areas for cooling and for the windgen) and figured the windgen would just carry the load. And it always did and kept the batteries full to the point the windgen was only putting in nominal amps and just dumping the excess in the dump coils.

The problem with the AGMs was that if it wasn't windy enough to keep them going through the night, they would die after using less than 70 to 100 Ahrs to 10.5v, which isn't good for AGMs. They did this during the first two months. Then, as the windy season slowed down here in Grenada (God it was a long windy and cold season) they kept doing this and getting worse. I let the Chandlery know yet they said there was no warranty and to contact Duracell who then refused to cover them out of the USA. So, I lived with them as best I could. Now they've gotten worse to the point I run the genset first thing in the morning and last thing before falling asleep (it's on now).

My belief is these batteries were not maintained properly on the shelf and were ruined before I got them. Sure at full charge they passed a load test. But, I can honestly say they never once passed a real world usage test. It was a mistake. I made the decision to get them. And, I have to live with it. I'm just disappointed about the lack of standing behind the 12 month free replacement just a couple months in making us deal with them for a year until we got to a point we can get proper batteries.

Thank you so much for all you input. I have plans to dock the boat when we get the lifepo batteries and will take all the proper steps and make sure all the settings are proper for the batteries. I also plan to replace the crunched solar panel to get back up to 780 watts. It's one big one out back over the David's and two out the sides like wings. And, the Victron Monitor (love the ap) makes it so much easier to keep an eye on things. Believe me. I don't even want to say to my wife we need to replace the lifepo Batts anytime soon. She'll kill me. And, I mean she would kill me, drag my lifeless body to the edge of the boat and throw my fatass to the sharks LOL

Thanks brother
 
Appreciate the additional detail. You may be right about improper maintenance on-the-shelf. I find that's an extremely common issue with auto batteries. I take a voltmeter with me and refuse any AGM that's under 12.7V or has a month/date sticker older than 3 months.

Glad to hear you have a good battery monitor. Make sure the temperature compensation is disabled once you have the LFP deployed. LFP won't care or suffer any ill effects if you're unable to get it fully charged every day, and it won't care about the lower charge current of the smaller array provided you can replace your daily usage within reason.
 
I just bought two of these for my sailboat... I'm in Grenada...

As tempting as it is, I'll forego the obvious joke on a solar power forum :) A friend in Barbados took this photo yesterday afternoon. I hope your boat isn't covered in ash. I imagine it would be a nuisance to clean up if it got below deck.

Barbados.jpg


BBC story:

 
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@snoobler Wow.
As a long time user of both agm (pure-lead so I can hammer them) and LifeP04, what you said in a mere paragraph or two with just the facts astounds me.

So what is your secret to being so concise and matter-of-fact? I try to say the same things, but end up with 300-message long threads or off into the weeds where focus gets lost.

Do you have some sort of secret AI software you run your responses through? If so, where can I get it? :)

Had to say thanks and no response necessary.
 
@snoobler Wow.
As a long time user of both agm (pure-lead so I can hammer them) and LifeP04, what you said in a mere paragraph or two with just the facts astounds me.

So what is your secret to being so concise and matter-of-fact? I try to say the same things, but end up with 300-message long threads or off into the weeds where focus gets lost.

Do you have some sort of secret AI software you run your responses through? If so, where can I get it? :)

Had to say thanks and no response necessary.

I'll assume you're being sincere. I kinda see my post as a wall of text, so maybe we have different standards. :)

I'm a certifiable battery nutjob, and it doesn't take much to get me to go off into the weeds. I've tested over 10,000 batteries in the last 7 years.

I'm also an engineer for an aviation company, and I have LOTS of practice trying to be as concise as possible to facilitate understanding of non-technical people (sales and management). I am not always successful. :)

Maybe it's a combo of the above two + luck. I've made many posts that were little better than a meandering stream of consciousness... :)
 
Totally sincere. Wall of text? No way - yours are mere post-it notes compared to my online sagas!

Ah, aviation! While I'm not a pilot, I do (did) plenty of burger-runs in GA aircraft, and used to get questions from those wondering why it wasn't a good idea to put an Optima in a Cessna, and I would steer them to Gill or Concorde or actual true aviation batteries. Then their eyes would gloss over when I informed them of the electrolyte acidity being different for one thing, different charge parameters and so forth. By then I'm in the weeds again. :)

..moving my rocking chair forward .. I come from the days when EV meant stripping a small Chevy Luv pickup, filling the bed with either Optimas or the new Enersys Hawker agm's (ooh flat!) , and trying to keep them all balanced. Heh, kids these days and their high-falutin BMS! :)

Solar charging meant trying to "fine-tune" your hysteresis SCC with HVD and LVD. PWM? waay off into the future. Ah, the clacking relays. Paying $20 / watt for panels...

So here I go again into the weeds. And I'm jackin the thread, so sorry about that people. Keep up the good work!
 
Totally sincere. Wall of text? No way - yours are mere post-it notes compared to my online sagas!

Ah, aviation! While I'm not a pilot, I do (did) plenty of burger-runs in GA aircraft, and used to get questions from those wondering why it wasn't a good idea to put an Optima in a Cessna, and I would steer them to Gill or Concorde or actual true aviation batteries. Then their eyes would gloss over when I informed them of the electrolyte acidity being different for one thing, different charge parameters and so forth. By then I'm in the weeds again. :)

Truth. I logged just over a mere 200hr in an old Mouseketer before the turn of the century. Haven't flown GA since. I re-did my own baffles, did an owner-assisted annual, etc., but there are things you don't compromise on. We got a Concorde despite the high price. :)

..moving my rocking chair forward .. I come from the days when EV meant stripping a small Chevy Luv pickup, filling the bed with either Optimas or the new Enersys Hawker agm's (ooh flat!) , and trying to keep them all balanced. Heh, kids these days and their high-falutin BMS! :)

LOL... Chevy Luv. Not sure I was quite driving age in that era, but I remember them well.

Solar charging meant trying to "fine-tune" your hysteresis SCC with HVD and LVD. PWM? waay off into the future. Ah, the clacking relays. Paying $20 / watt for panels...

Oddly enough, you've just identified how the Electrodacus system works... and it has a near rabid cult following.

So here I go again into the weeds. And I'm jackin the thread, so sorry about that people. Keep up the good work!

It happens. Thanks. Take care.
 
@curtism - I'm sorry man, we got on a roll here. I don't normally do this to someone elses thread.

@snoobler - Yeah, I was too young to drive, but I got enlisted to help wrench on it. Learned about wrapping electrical tape up to the head of your wrench the hard way.

We never raced this guy, but I got to see him once. Old historical footage of an electric Datsun (aircraft starter for motor) going from pure-lead, nicads, and finally to lithium - loaned from guys runnng A123 packs. We learned the same lesson and know the story of why this team was called Plasma-Boy Racing. :)


This is Will's next step. Get away from the tear-down bench videos, and get to the track!

Again, sorry for the jacking curtism...
 
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Having recently gone thru a good sized pile of Duracell-branded 105 AH 12v "deep cycle" lead batteries, I can say with some confidence they DO NOT meet their published kWh ratings--not even to the 50% derating usually followed with lead batteries. When bought brand new in late 2019 I personally equalized and charged them before installation in our 48v solar system. Eight of them in series/parallel SHOULD have been good for at least 5 kWh--we were lucky to see 3.5 kWh come out of them at night, after full-charge and floating them during the day. Bought thru Batteries Plus, a big specialty chain that focuses on batteries like this. Tried to return them and was told "they appear to pass our load test, you won't get a refund unless you raise hell with the Duracell company". And of course, Duracell did not return phone calls.

Ended up buying lithium packs from Big Battery. Lot more expensive but DAMN well worth the expense.

I would swear that US-made commercial lead batteries, in general, have been declining in quality for years. A car battery used to last 5-7 years routinely and often much longer. In recent years I've ended up fighting with the dealer after only 1-2 years. They won't hold a charge sufficient to start the car for more than a couple of days--no matter what measures I take. Even disconnecting it from ANY load did nothing.
 
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