Trying to understand Link 1000 battery charging cycle

[wgkenney]

All,

I have a 2006 Benteau 473 which my wife and I have owned for one season. As we start our second season I want to ensure that I am keeping our batteries in the best condition possible. The boat is on its fifth year and the batteries still seem in very good shape. I have 3 4d wet cells (2 house and 1 inverter) and 2 series 27 (one starts the diesel other starts the genset). Gives me a total of 600 ahr.

We have a Freedom Marine 20 inverter / charger and a link 1000. I've been reading the manuals and forums here and I think I have most of this. I'm a little confused on a few points and could use some help clarifying.

I'm a former submarine officer so the battery charging concept and cycle is actually very similar to how we charged our batteries on my sub. I understand the bulk cycle uses full amps as the voltage builds up to 14.5 volts and then shifts into acceptance with constant voltage and reducing current until you shift to float at 13.5 volts or so for my system. Then holds 13.5 volts at small amps in float.

Here is what I'm not sure of:

Does the link system consider my battery charged when it shifts from acceptance to float? I think the manual says that the green battery lights should flash when fully charged ... but I have never seen that happen.

I know that my system is set so the charge is "complete" when the voltage is above the 13.2 v setting and amps are less than 3% (may be too high but what the previous owner had) of my capacity. But is that the point where the system shifts from acceptance to float? Or does that happen during the float cycle.

I have seen on several posts that the system also looks at the amp hours used as well. I don't think my system does this. I'm actually a bit concerned about overcharging as I can get some decent positive amp hour numbers at times when I go a few weeks between being out. I think the system is suppose to recal the CEF (mine is at 81% right now) and zero the amp hours. I know that it does zero positive amp hours as soon as the battery comes off float and starts to discharge.

Last question. Once there is some level of positive amp hours should the system come off of float and allow discharge or is it set up to constantly be on float. Back to my question of when does the link consider the charge done.

Any help would be great. I'm trying to learn as much as I can about all the systems on board.

 

[Stu Jackson]

wgk,

One of my favorite subjects!

The Link says your bank is full when the parameters (13.2V and 3%) are met and switches your Link signal to your Freedom I/C to float.

Please read this, I'm sure you'll have more questions:

http://c34.org/bbs/index.php/topic,4922.0.html

You can also do a search on this board for "Gotcha" and my name for more reading.

There is no "done" it stays on float until you turn it off by pushing the charge button again.

You have a very good system, and we can help you fine tune it.

 

[wgkenney]

wgk,

One of my favorite subjects!

The Link says your bank is full when the parameters (13.2V and 3%) are met and switches your Link signal to your Freedom I/C to float.

Please read this, I'm sure you'll have more questions:

http://c34.org/bbs/index.php/topic,4922.0.html

You can also do a search on this board for "Gotcha" and my name for more reading.

There is no "done" it stays on float until you turn it off by pushing the charge button again.

You have a very good system, and we can help you fine tune it.

Okay, this was very helpful. I think I have this.

The key thing I was not understanding was that when the Link 1000 hits its criteria of voltage and the 3% it shifts from acceptance to float. Seems obvious now that I know the answer. So the actual charge is really the bulk and acceptance stage. Float just follows on. Actually this is pretty much the way it works on a submarine as well.

As long as I have discharged at least 10% of the capacity, the link should turn on 3 green lights and flash the forth to signify it is done and recalculating the CEF then will reset to zero. I have noticed it doing this in the past.

Right now I've been on float for a few weeks (had to pick daughter up at college and there was bad weather this past weekend) so my overcharge is a bit higher than normal. I need to take some logs on the amps that are being displayed in float mode.

Now the other thing is that I have noticed that in my normal cylce of weekend out and charge when I get back in the slip .... the acceptance phase is realatively short. Based on what I have seen here that is likely due to the 3% parameter. With a capacity of 600ahr that 3% is 18 amps. I don't need the refirgerator to come on to get below that number. And if the charge is secrued at that point, ahr reset to 0 and CEF recaculated I have likely been undercharging. My float will help out but I likely need to reset that back to factory default of 2% (not sure why previous owner had it at 3%).

one more question ... sorry... how does the CEF recalulation work. I'd like to understand the 81% that I have and how the recal is done. I could not find it in any of the link literature. If I understand it right, for every 1 amp hr I take out I have to put back in 1.23 amp hr to move the amp hr meter up 1 amp hr.

 

[Stu Jackson]

Yes, you "got it." I would recommend that you revise the parameter to 1%, fridge or not, so you won't ever prematurely show full, but if you raise the voltage, too or by itself, that should work (discussed in the link article). One or both should work, but you know your uses.

Since you understand the need to reset the default(s), then this should avoid having your charger (Freedom) hop from "charge" to "acceptance" and too soon to float. Float, when first switched to, is NOT full, since you still have that 2% (or 1%) to go. That's why float isn't necessarily full. Once you maek this change, Ron's comment of "when I see 0.2A on my monitor I know it's [finally] full."

To learn more about the CEF, download the Link 2000 manual, which IIRC has more info than even the Link 1000. Usually it pushes it UP, not down (IIRC it starts at A87 or A90 depending on battery type), but I'd have to go back to the manual to answer your ? as to "how" it actually works.

In any event, if we follow Rich's advice in The Gotcha, setting it to manual 94% covers that, doesn't it?

 

[wgkenney]

Yes, you "got it." I would recommend that you revise the parameter to 1%, fridge or not, so you won't ever prematurely show full, but if you raise the voltage, too or by itself, that should work (discussed in the link article). One or both should work, but you know your uses.

Since you understand the need to reset the default(s), then this should avoid having your charger (Freedom) hop from "charge" to "acceptance" and too soon to float. Float, when first switched to, is NOT full, since you still have that 2% (or 1%) to go. That's why float isn't necessarily full. Once you maek this change, Ron's comment of "when I see 0.2A on my monitor I know it's [finally] full."

To learn more about the CEF, download the Link 2000 manual, which IIRC has more info than even the Link 1000. Usually it pushes it UP, not down (IIRC it starts at A87 or A90 depending on battery type), but I'd have to go back to the manual to answer your ? as to "how" it actually works.


In any event, if we follow Rich's advice in The Gotcha, setting it to manual 94% covers that, doesn't it?

Thanks .. this all really helps. I hate not understanding how the "automatic" systems are working in the background