Your favorite house battery?

[hellosailor]

Clipper- Your old batteries FIT well. They've WORKED well. The entire boat's electrical system apparently is set up FOR THEM and works well with them. And of course, all the cables FIT AS IS. So why not just pull one up, check the label, buy the same thing if they are still available. Buy the same size with the same terminals from another good source if not. Not much has changed in ten years, unless you want to invest a fortune in a lithium system, which may or may not still be the high-end choice in ten more years. Ten years is a damned good run.

[Adelie]

Originally Posted by moseriw

Ummm.... yes, AGMs have life cycles (our oldest bank of AGMs is finally going down the tubes, at the end of 11 seasons)...

Well it is said thst AGM's have about 1000 to 1200 recharging cycles.
Hmmm how come that your batteries lasted 11 years AND it is recommended to charge/discharge them continously. assuming one cycle per day (solar charging) the banks shoud have been done 1200/365 = 40 month.

11 years are about 4000 cycles then.

Probably cycling a lot shallower than 50%.

[mitiempo]

Originally Posted by moseriw

Almost all electric units work between 13,8V (fully charged) and 11V. It makes no sense to use batteries that can be discharged down to 2V.

Still not sure which batteries you are referring to that can be discharged to 2 volts. No 12 volt battery that I have ever come across can be taken that low.

A 12 volt battery is generally considered dead at 10.5 volts. Trojan's chart below shows the often mentioned 50% SOC to be 12.1 volts for a 12 volt battery.

Even 20% SOC is 11.66 volts

[TeddyDiver]

Originally Posted by mitiempo

Still not sure which batteries you are referring to that can be discharged to 2 volts. No 12 volt battery that I have ever come across can be taken that low.

A 12 volt battery is generally considered dead at 10.5 volts. Trojan's chart below shows the often mentioned 50% SOC to be 12.1 volts for a 12 volt battery.

Even 20% SOC is 11.66 volts

Dunno about moseriw's intentions but for me it makes perfect sense. A 2v cell is about at 2v at 50% DOD.
Two volt batteries would be the perfect batteries for me.

BR Teddy

[mitiempo]

Originally Posted by TeddyDiver

Dunno about moseriw's intentions but for me it makes perfect sense. A 2v cell is about at 2v at 50% DOD.
Two volt batteries would be the perfect batteries for me.

BR Teddy

I don't think he was referring to 2 volt cells.

Not that common but a good way to go if you have the money and space.

[moseriw]

I am talking about common 12v car batteries :
Absorbent Glass Mat (AGM) = VRLA (valve-regulated lead-acid battery)

interresting links about lifecycles:

https://www.civicsolar.com/support/i...-agm-batteries

and:
-----------------------------

1- Cyclic life
The battery life is mainly determined by the use cycles of the battery. An AGM or flooded battery may have a life of 300 to 700 cycles under normal use; however that of a gel battery may be from 500 to 5000 cycles .

The battery completes a cycle when it is charged and discharges once. In a solar system, the batteries are charged during the day and they are partially discharged during the night. In this case, one cycle corresponds to one day.
2- Depth of Discharge (DOD) effect
The harder the battery works, the sooner it will fail. This means that a higher capacity withdrawal would result in a reduction of life cycle. Here is a table that explains the effect of depth of discharge.
Typical VRLA Battery Cycling Ability vs. Depth of Discharge Typical Life Cycles Capacity Withdrawn Gel Battery AGM or Flooded Battery
GEL / AGM
100% 450 200
80% 600 250
50% 1000 500
25% 2100 1200
10% 5700 3200
----------------------------------
source: https://www.civicsolar.com/support/i...rmance-factors

[moseriw]

conclusion:
we need a charging computer between the solar (mine is 6 to 16Amps) and AC chargers to monitor and regulate charging between say 95% and 50% to keep cycles low. Did not find a solution but surveying.

[masonc]

We recommend Trojan for our solar customers, their technology is cutting edge and they are a great company. If they have a battery in the same form factor as your previous units, I would get them.

[Frankly]

Anybody found gel batteries for sale/ sail. I have one used for starting service on my 18 ft outboard that is 12 years old still going strong.

My suspicious nature kicking in, these things were so successful that the battery mfgs stopped making them.

[TeddyDiver]

Originally Posted by mitiempo

I don't think he was referring to 2 volt cells.

Not that common but a good way to go if you have the money and space.

Seems that he has a bit of language and cultural barrier to be understood.

2v battery prices vary a lot from Chinese (<$80/400Ah) to European/USA (>$350/400Ah) hard to find anything between..

BR Teddy

[masonc]

Originally Posted by Frankly

Anybody found gel batteries for sale/ sail. My suspicious nature kicking in, these things were so successful that the battery mfgs stopped making them.

Sure, manufacturers found a product vastly superior to their competitor's product so they stopped making them.
Deep-Cycle Gel | Trojan Battery Company
Gel are common in solar applications.

[moseriw]

Trojan 8D-GEL 12V, 225AH (20HR) Gel Battery $755.00

Varta Promotive Silver N9 SHD 725103115 12V/225Ah 1150 A EUR 289,90

Is GEL really an option?

EUR/USD is nearly even I'll get 1,6 AGM's for 1 GEL.

If I fix charge managment properly I'll get far more cycles out of the AGM's

[hellosailor]

"If I fix charge managment properly I'll get far more cycles out of the AGM's " Indeed? If you ask any one manufacturer, who makes both gel and agm batteries, which one will provide the greatest number of charge cycles? Funny thing, the chances are that today they will say GEL. Fifteen years ago they might have said AGM, but that has been proven somewhat mistaken. If you don't get the numbers from the same vendor, then all you are comparing is apples to oranges. The last time I got solid numbers was from Deka/East Penn. They said yes, they used to say AGM, but not any more. They soft-sell GEL because it is so easy for owners to ruin them with improper charging. Like Trojan, they manufacture in the US not in Austria, so they would not be a good local choice for you. Whereas Varta could be a short trip away from you. Shipping lead overseas is only economically feasible if you are a Chinese manufacturer. FWIW.

[mitiempo]

Originally Posted by TeddyDiver

Seems that he has a bit of language and cultural barrier to be understood.

2v battery prices vary a lot from Chinese (<$80/400Ah) to European/USA (>$350/400Ah) hard to find anything between..

BR Teddy

Try Rolls/Surrette made in Canada.

[moseriw]

Hellosailor

Just participating in an interresting discussion. I have 3 + 1 new Varta 12V 225 Ah