Lifeline AGM's Fully Charged Voltage?

[a64pilot]

Originally Posted by Exile

Didn't you say you had 1kw of solar, or am I confusing your set-up with someone else? If that's the case, do you then need to resort to your Honda generator to get to 100% SOC? (While you're away from the dock that is).

Yes, but if you look at Maine Sails chart, you’ll see that it took 7.5 hours to get to fully charged, and that was at .15 C which as Nolex pointed out is 100 amps for me.
I see 50+ amps for only maybe an hour or so with Solar and of course a slow ramp up and down from that.
It’s actually about hours of charge and not total power made, a 1000 W of panels will deliver about 330 AH in a good day, which coincidentally is 50% of my banks capacity, so at first blush you would say it will easily recharge the bank, cause I’m closer to 85% SOC in th morning than I am 50% SOC
However the last few hours of charging, the bank won’t accept what the panels can deliver, and we are back to their being on average only about 5 to 5.5 hours of usable Solar in a day.
It will get me into the 90’s likely the high 90’s, but that last several percent of charge has to be dribbled in over time, and you run out of time.

Now if I had say 2000W of panels it would get me charged, but only because the bigger bank would add usable output time, not additional power.
But if I have an hour of generator time in the morning ideally before Solar is making power, then I’ll easily get to 100% SOC, for two reasons, first the bank can take all the generator can make for awhile and of course it adds an hour of charge time.

I’m convinced that people that live on Solar alone often don’t get to fully charged, but their battery chemistry is more tolerant of that than an AGM bank, it’s why AGM isn’t likely a good chemistry for cruisers, unless it’s special needs are coddled to.

[kmacdonald]

All this battery talk might be interesting but if you are spending a great deal of money to perfectly charge your batteries to make them last longer, you might want to consider spending less on exotic charging systems and more on replacing batteries when they die. Batteries are cheap compared to engine or generator run time.

[CarlF]

This spring I gave up on Lifeline after the house bank had lost more than 30% of it's capacity in less than 4 years. I went to Fireflys.

I was incredibly careful with these Lifelines. They rarely went below 70% and never below 50%. We only spend about 3 months of the year at anchor (where I have both a genset and solar to keep them charged). The rest of the year they are plugged in on a Victron Multi at a marina almost every night as well as the solar. Voltages all set to spec.

The only think I didn't do was a monthly restoration charge. I did it about twice a year but find them a pain in the neck. It takes a whole day watching the charger.

I worry about other things on the boat not liking the high voltage during a restoration charge so I isolate as many things as possible - probably not really a problem but some things onboard don't list a maximum voltage. It's pretty much a wasted day. Keeping a boat maintained is tough enough without this added monthly chore.

Since this happened, I've bumped into a surprising number of people who say that their Lifelines failed early despite good care. Some said that previous Lifelines had lasted much longer. Is there a chance something changed at Lifeline?

[Exile]

Originally Posted by a64pilot

I’m convinced that people that live on Solar alone often don’t get to fully charged, but their battery chemistry is more tolerant of that than an AGM bank, it’s why AGM isn’t likely a good chemistry for cruisers, unless it’s special needs are coddled to.

That's exactly the conclusion I was coming to based on this discussion. You often read reports that solar +/or wind allows cruisers to be largely indpt of fossil fuels but that's probably only correct to maybe 85% or so. As you say, if you have (expensive) AGM's then you may still have to rely more on fossil fuels to get decent battery life than many realize.

I went with Lifelines vs. flooded mainly because they're under the bunk where I sleep, and secondarily because their location makes it a PITA to keep tabs on the water.

[Exile]

Originally Posted by CarlF

This spring I gave up on Lifeline after the house bank had lost more than 30% of it's capacity in less than 4 years. I went to Fireflys.

I was incredibly careful with these Lifelines. They rarely went below 70% and never below 50%. We only spend about 3 months of the year at anchor (where I have both a genset and solar to keep them charged). The rest of the year they are plugged in on a Victron Multi at a marina almost every night as well as the solar. Voltages all set to spec.

The only think I didn't do was a monthly restoration charge. I did it about twice a year but find them a pain in the neck. It takes a whole day watching the charger.

I worry about other things on the boat not liking the high voltage during a restoration charge so I isolate as many things as possible - probably not really a problem but some things onboard don't list a maximum voltage. It's pretty much a wasted day. Keeping a boat maintained is tough enough without this added monthly chore.

Since this happened, I've bumped into a surprising number of people who say that their Lifelines failed early despite good care. Some said that previous Lifelines had lasted much longer. Is there a chance something changed at Lifeline?

I hope not! I got 7 years out of my last set with comparable treatment to what you described, but I was probably pushing it. Lifeline recommended a 20A portable charger made by CTek which I use for equalizing/conditioning and also as a backup. My 2-batt. house bank can be isolated which allows me to keep the lights on off one while I'm equalizing the other. The CTek also has a feature which senses when the batt. is finished equalizing and then automatically goes back to float. Btwn that & my Lifelines, it makes it easy to set & forget, or at least do some other task onboard while each batt. is equalizing.

[a64pilot]

Originally Posted by kmacdonald

I know one of my batteries will NEVER get to 0.5%C end amps at 14.8 volts no matter haw long it's connected and it's a fairly new battery. The 0.5%C current might be more than we can hope for. Maybe a more realistic 1 or 2%C figure might be more appropriate.

If it’s not a Lifeline battery, and I assume it’s not with that voltage, .5 may not be a desirable target, I believe a Lifeline can get that low partially due to low internal resistance, another battery brand maybe can’t, and trying to may be overcharging?

[noelex 77]

Originally Posted by a64pilot

I’m convinced that people that live on Solar alone often don’t get to fully charged, but their battery chemistry is more tolerant of that than an AGM bank, it’s why AGM isn’t likely a good chemistry for cruisers, unless it’s special needs are coddled to.

Boats that are primarily powered by solar need to have enough charging capacity to cover poorer seasons, or cruising grounds. They therefore tend to achieve 100% SOC, most of the time, relatively early in the solar day.

However, I agree AGM batteries are not ideal for many boats where the primary charging power is solar. There are likely to be locations and seasons where 100% SOC is not achieved on regular enough basis to ensure a long life from this type of chemistry.

[kmacdonald]

Originally Posted by a64pilot

If it’s not a Lifeline battery, and I assume it’s not with that voltage, .5 may not be a desirable target, I believe a Lifeline can get that low partially due to low internal resistance, another battery brand maybe can’t, and trying to may be overcharging?

You are correct. It's a Sams Club LA battery. (two 6v in series) I've never seen any specs on the batteries but they do last a long time even being abused to the max. Recharge when the frig quits and the beer gets warm.

[john61ct]

The endAmps spec is usually available from the maker of a quality battery.

The total charge time does of course increase if your early stages are not at at least .15C for a flooded bank.

May even take twelve hours to get to 100% Full in a low current context like solar. 100A for the first 2-4 hours is not very high if you have a large bank and consume a lot of AH per day.

That is a reflection of insufficient charging power, not something wrong with the charging protocol spec.

And a much bigger problem to solve for those with AGM.

[john61ct]

Originally Posted by kmacdonald

You are correct. It's a Sams Club LA battery. (two 6v in series)

If Duracell, you can get the detailed specs from EPM/Deka, the maker.

Flooded I assume, can get to the electrolyte?

[john61ct]

Originally Posted by noelex 77

Boats that are primarily powered by solar need to have enough charging capacity to cover poorer seasons, or cruising grounds. They therefore tend to achieve 100% SOC, most of the time, relatively early in the solar day.

Wut?

Most solar-mostly setups I've seen are only sufficient in good weather, not sized for short or cloudy days.

Much **less** likely to regularly get to 100% Full, except when the owner knows the 2-3 hours ICE Bulk stage in early AM "trick".

Which may be 4-6 hours depending on the C rate.

In any case total charge time requires 5-8 hours even with plenty of current available on demand.

Those claiming they get to 100% Full before noon are kidding themselves, not measuring endAmps.

[john61ct]

And yes, anybody claiming long life should really only do so knowing the residual capacity SoH%.

Of course if you push past 70% you can get many more years, but that "doesn't count" when discussing the effect of im/proper care on longevity.

People cruising in primitive locations need predictability, and should be replacing their bank between 70 and 80% SoH, depending how long before they return.

Just waiting for failure symptoms to become obvious is a game for weekenders and cruisers staying close to well-developed coastlines.

But it is possible with real coddling to get 5+ years from quality AGM like Lifeline even on that proper-EoL basis.

But with less than optimal care even the best most robust FLA can easily be murdered in a season or two.

[noelex 77]

Originally Posted by john61ct

Wut?

Most solar-mostly setups I've seen are only sufficient in good weather, not sized for short or cloudy days.

Much **less** likely to regularly get to 100% Full, except when the owner knows the 2-3 hours ICE Bulk stage in early AM "trick".

Which may be 4-6 hours depending on the C rate.

In any case total charge time requires 5-8 hours even with plenty of current available on demand.

Those claiming they get to 100% Full before noon are kidding themselves, not measuring endAmps.

Good days can be averaged with bad days using the battery bank’s capacity. But battery capacity is not sufficient to average the good months with those times of the year when the isolation is poor.

So, for example, if you have enough solar power to run the boat in winter, or even just in spring and autumn in a sub tropical location there will be heaps of power during summer.

However, there are many different ways to produce power with no ideal answer. I think John most of your posts assume the primary power generation will be via a generator, or at least that a generator, or engine will be regularly used to produce power. This is true for many boats, and can be a good solution, but there are alternatives. Boats equipped with enough solar power to provide all, or nearly all, their power throughout the year are not unusual.

Many of these boats are often doing what you think is impossible such as hitting end amps by noon.

[rom]

Originally Posted by kmacdonald

I know one of my batteries will NEVER get to 0.5%C end amps at 14.8 volts no matter haw long it's connected and it's a fairly new battery. The 0.5%C current might be more than we can hope for. Maybe a more realistic 1 or 2%C figure might be more appropriate.

Now that is interesting information. I actually did the test myself raising float voltage of my MPPT close to absorption voltage. It would take about 90mn to go down to 1% from 2% and the batteries would stay there accepting 1% forever.


Could it be that some of us have been waisting time and money trying to reach the 0.5% trailing amps advocated here every single day by our forum expert ? Overcharging their batteries and actually shortening their life ? I hope not. I am glad we are making progress.

[sailinglegend]

Originally Posted by john61ct

.....Of course if you push past 70% you can get many more years, but that "doesn't count" when discussing the effect of im/proper care on longevity.....
...Just waiting for failure symptoms to become obvious is a game for weekenders and cruisers staying close to well-developed coastlines....

Lifeline say replace the bank when down to 50% - and then only if the capacity is too low for normal use. Other manufacturers recommend replace at 80%.

We are full-time liveabords in the Med - not weekenders!!!

So we started with a very big bank of 1050Ah and when it got down to 450Ah it is was too low for our cruising needs so we replaced them - this time only 610Ah - but with more solar.

This worked out at £123 per year!!!!!