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witzgall · 05-02-2019, 06:54

A hopefully not too sales-y comment to the original poster. The SG200 will help with your issue. We have a Carbon Foam profile, and you will free yourself from synchronization drift errors. My wife and I cruised for two years with an old Link 10, and the issues you state are ones we experienced, even with the LIFEPO4 we were using.

Chris

admiralslater · 05-02-2019, 07:47

Not to salesy . That is very interesting. I am running a bunch of victron equipment with Bluetooth which I really like . Will look more closely later

admiralslater · 07-02-2019, 14:44

I planning to do the reboot on the FF in a day or so . My question is regarding trailing amps at the end of charge .
Is this taken in a no load situation
I s the number a percentage of bank size (525)
Will the ampmeter on my sterling bc be a reasonable indicator
Wish me luck i dont want to by new batteries

FlyingScot · 07-02-2019, 17:26

Quote:

Originally Posted by admiralslater

I planning to do the reboot on the FF in a day or so . My question is regarding trailing amps at the end of charge .
Is this taken in a no load situation
I s the number a percentage of bank size (525)
Will the ampmeter on my sterling bc be a reasonable indicator
Wish me luck i dont want to by new batteries

No load situation doesn't matter as the batteries need to have excess charging amps available above and beyond what the boat is using. Once the charging amps are available but not being accepted by the battery is what defines tail current/trailing amps.

The Victron BMV-712 I have allows you to set tail current as a % of bank AH. That coupled with time resets the 100% SOC. According to the demo mode of the Victron Connect app, The 700H, 700 & 702 have the exact same settings.

Firefly specifically states in the July 2018 manual:
For a complete charge cycle, charge the G31 to 14.4V/L15+ to 4.8V with temperature compensation (bulk phase) and continue charging until the charging current drops to 1.5A for the G31 or 6A for the L15+ (absorption phase time will vary). You DO NOT need to fully charge the batteries each cycle in order to maintain the capacity and only need to perform a complete charge cycle when you want to maximize the capacity for the following discharge cycle"

My bank is 450AH made up of three 4v L15+ batteries:
6AH / 450AH = 1.3%.
I choose to set mine at 5 minutes.

Your bank size and battery choice will require a different answer.

admiralslater · 09-02-2019, 07:22

Doing my recovery now , we will see , this morning had the sterling 60 amp charger and the alternator from one engine pushing 98 amps into the battery for about 20 minutes. I only have small fram alternators so decide not to push them . Boy where they warm .
My question is . Is the tail amperage for a 525 amphere bank the same as for a single battery. I suspect the same as right now the charger in a no load situation is putting out 14.2 volts and 12.0 amps
The charger is set to 14 .4 , so I guess we are in the long absorbtion cycle

witzgall · 09-02-2019, 07:47

Quote:

Originally Posted by admiralslater

Doing my recovery now , we will see , this morning had the sterling 60 amp charger and the alternator from one engine pushing 98 amps into the battery for about 20 minutes. I only have small fram alternators so decide not to push them . Boy where they warm .
My question is . Is the tail amperage for a 525 amphere bank the same as for a single battery. I suspect the same as right now the charger in a no load situation is putting out 14.2 volts and 12.0 amps
The charger is set to 14 .4 , so I guess we are in the long absorbtion cycle

The tail current is per battery in parallel. So you want to multiply that value by the number of batts in parallel.

admiralslater · 09-02-2019, 09:12

I am 1. 8 amps away, I wonder how long the last bit will be

john61ct · 09-02-2019, 15:50

With lead, the last 10% SoC can be well over half the total charge time.

Especially with high-CAR chemistries.

FlyingScot · 09-02-2019, 16:19

Quote:

Originally Posted by admiralslater

I am 1. 8 amps away, I wonder how long the last bit will be

From the July 2018 manual:
Restoration Charge
As stated, Firefly Batteries can operate in a partial state of charge for long periods of time without sustaining any permanent damage. The usable capacity will decrease, however, with each cycle within a partial state of charge, up to a point. In order to regain the full original capacity and in some cases more, it is necessary to perform a restoration charge. To perform the restoration charge: charge the G31 to 14.4V or the L15+ to 4.8V and continue to charge until the current drops to 0.6 A on the G31 or 3A on the L15+. Fully discharge the battery to 10.5V (G31) or 3.5V (L15+), and then repeat the same charge cycle. At this point, the battery should have regained full capacity.
Safety

So, are you doing a restoration charge or normal charge?

admiralslater · 10-02-2019, 06:37

I am doing or have done a long over due restoration charge. The batteries suffered a complete discharge for about two months following an un known current leak after which I could not restore them with shore power due toa delayed rebuild of the shore power system . Solar brought the system to a usable state and yesterday i hooked up to a friends 8 kw genset for 12 hours . So we shall see were we are .

john61ct · 10-02-2019, 07:24

So when will you next have access to shore power?

In the aftermath of such a drastic misadventure, it may be a good idea to do the full charge / discharge routine a couple / few times in a row, obviously in very controlled circumstances.

Personally I would have hauled the batts ashore to charge a lot sooner, it does not take any special boat-based gear to care for a bank, could even make do with a garage style charger long as you have an ammeter.

admiralslater · 10-02-2019, 08:10

I missed that detail between full charge and restoration charge tail current . I got it too 1 amp per battery so 5 amps

admiralslater · 10-02-2019, 08:12

Quote:

Originally Posted by john61ct

So when will you next have access to shore power?

In the aftermath of such a drastic misadventure, it may be a good idea to do the full charge / discharge routine a couple / few times in a row, obviously in very controlled circumstances.

Personally I would have hauled the batts ashore to charge a lot sooner, it does not take any special boat-based gear to care for a bank, could even make do with a garage style charger long as you have an ammeter.

I agree John however that was not feasible at the time . This week we will be in Martinique an I will try to get that done

john61ct · 10-02-2019, 08:14

yes .005C is a pretty common endAmps spec for Full-full.

Even a tiny solar panel can do the last few hours, pretty wasteful to burn genset hours after the first couple, say 85% SoC.