Battery question for you electrical types....

[Dick 119]

We have a Heart 3000 watt inverter charger with a Link 2000 controller on our boat. As I understand the Heart system it only charges to about 90% of battery capacity and then goes to accept and then float.

The problem is when we are on the hook and using the generator to recharge we never replace all the amps drawn before the system goes to float. At float it is only putting in a very minimal amount of amps. After a week or so we are down 250 amps on a 360 usable amp system. Naturally the voltage drops very quickly when we get to this point.

My question is, other than adding solar to slowly charge all day, is there a charging system that will replace more amps used and charge accordingly or are all systems based on voltage replacement? We use between 80 and 100 amps per day.

Dick
S/V ONE9TEEN
KE7KRL

 

[Buck Harrison]

Dick,

I have the same setup.

If you run the gen long enough so that the Link 2000 goes to "float", the batteries should be completely charged just as they would be if charging from shore power.

Do you use the "power share" function of your Link 2000R and set the charge rate up to (as high as) 50amps when you're recharging w/ your generator?
By setting mine to 50amps, it takes 3-4 hours to recharge my batteries to "float", depending on amount of -amp/hrs.

I think the default "power share" setting is 15amps. If that's the rate of charge you using w/ the generator, then it will take MANY hours to recharge just as it (probably) does w/ shore power.

Make sure to set the "power share" setting abck to 15amps when you return to shore power or the high charger amperage usage may trip your shore power breaker, especially if you turn on your A/C(s).

 

[Dick]

Buck..I'm not on power share. It only takes about 1.5 hours

to completely charge to float. Our generator is a 8kw Fisher Panda and I charge at 50 amps. My porblem is not the time to float, but the amount of
-amps the 2000 shows at float. Usually about -50 amps less than we consume, which after a week grows to over -200. Does yours replace all the amps before float??

Dick

 

[Buck Harrison]

YES,

just as it does if being charged by shore power.
That sounds awfully quick to recharge 80-100 amp/hrs even with a charge rate of 50 amps
Suggest you call Xantrix and get a technician to help you. Your batteries should charge completely whether using gen set or shore power.

 

[Dick]

Buck, I have called them, and they insist that it is operating

correctly, and that I should ignore the amps used and only worry about the voltage. They can give no explanation why once I'm back in our slip after about 24 hours the -amps are replaces by a slow climb into + amps..

 

[Ross]

I am not certain but it seems to me that

charging at that rate (50amps) will drive the battery voltage high enough to signal a "float" ready condition. Is it posible to reduce the charging rate? You seem to be pulling about 8 amps per hour but trying to recharge at 6x that rate. That may be alright for a starting battery but I don't think that a deep cycle battery works well at high discharge and recharge rates.
That is my thought on the matter without having studied the details of the differences in battery construction.

 

[Buck Harrison]

Dick,

When you are running the generator what (+) amperage is displayed after (say) 1/2 hr of charging?
What(+) amperage is displayed when charging on shore power?

You say you're not on "power share", yet you say you're charging at 30 amps. When my "power sahre" is set on default (15amps) the charging amperages after an initial spike drops off quickly (within a minute or two) to 15 amps or less.

 

[Stu Jackson]

It's pretty simple

Once the charger goes into float, turn it off and then back on again. Check your charger specs an manual and you ill most likely find, if it is similar to our Freedom inverter / charger, that the algorithm in the chip will do bulk and acceptance for a minimum period of time regardless of what the battery voltage is ONCE the unit starts up. Just cycle.

Conversely, use the 50% to 85% (or 90%) charge "window" that cruisers use, and just live with the 90% until you get to a dock for shorepower charging, because that last 15% to 15% is gonna cost you big time in running a generator or an engine. Start charging when your Link 2000 says you've used half your house bank, and just charge up to 85-90%. Easy.

 

[Dave]

1 Stage Versus 3

F.Y.I.

The Heart 3000 Watt Inverter / Charger has a charging capacity of 140 amps not 50.

The "power share" function of the Inverter / Charger allows you to control the amount of amps the charger will draw (AC) not the output DC amps. With 15 Amps AC you should be able to charge 140 amps DC.


PS: I like Stu's response. I believe the different changing states have a default time that can be overridden by the Link 1000 or 2000. The easiest approach is to turn off the charger when it reaches float and restart. The amount of amps absorbed during bulk charge will be based on the batteries current state of charge. This basically is chargeing the batteries using a 1 Stage Charger versus 3.

 

[Dick]

Dave, I guess I wasn't clear on the charging amps. Yes

it does charge at 140 amps, but that is DC, which, to my knowledge, power share does't control. The 50 amps I was referring to was the AC input amperage.

 

[Stu Jackson]

Dave makes a good point that I forgot to mention

which is battery acceptance. Once the batteries get 90% charged, they can't absorb much more amps anyway, which is the reason that the chargers taper off their amperage at float anyway. The "power share" feature has nothing to do with the DC end, only the a.c. input, which allows it to avoid tripping the generator. See the link (written in 2004).

 

[walt]

??

I’m possibly way off here but will throw out an idea..

The system charging is making decisions on which stage to charge at mostly or entirely based on voltage. If the location where the voltage is being measured is not at the battery but at the other end of a too long or too small of gauge wire, the voltage measurement will include both the battery voltage and the voltage loss in the wire and will cause the "smarts" in the charge controller to shut down the charging too early. For example, if the link 2000 was sensing voltage at the charger and there was a long small diameter wire between the charger and the battery, the link 2000 algorithm would be sensing both the battery voltage and the loss in the wire and for example, think the batteries had less capability than they actual had and go to float too early.

 

[GuyT]

You are pushing too much charge current!

You said that you have 360 Amp usable system(sounds like 3 group 31's??) and you are charging with a 140 amp source. That charge rate is too high! Keep to a C/5 charge rate for good charge acceptance or in your case 360/5 =~ 75 amps.
It will take you longer to charge but, you will put more back in the battery.

 

[Benny]

You indicate your bank has a usable capacity

of 360 amps. Is it correct for me to understand that this is the 50% discharge limit and that your bank has a total capacity of 720 amps? An energy survey is used to size the battery bank necessary for a boat. You indicate your usage is approximately 100 amps a day and that you have the ability to recharge daily through a generator. It seems you have sized the battery bank to big for your usage. 100/720 = 14% on day one and 100/648 =15% on subsequent days provided you recharge to 90%. At these rates of discharge the charge acceptance of your batteries is very low requiring extremely long hours of recharge which perhaps you may not be providing. A battery bank charged to 90% will show a voltage after an hour's rest of 12.58V. It you do not get this reading you are not charging the batteries long enough. Life is not simple as the reality is that while you are trying to recharge your batteries your refrigerator and perhaps other components may be simultaneously drawing power out so its very hard to get a solid voltage reading. Your battery bank is the size of someone's with your usage that has to go three days between recharge cycles. Let the bank go down to close to 50% discharge and your powerful charger will have them up to 75% charge in two hours and up to 90% in approximately another 6-12 hours depending on your acceptance charge rate. To recharge small amounts on a daily basis would probably take you just as long every day. You do not indicate how long you are running the genset but if you are running into an amp deficit I'm afraid you may not be running it long enough. The charging times given are just provided to illustrate the point as I'm not familiar with your charger specs. Some cruiser divide their banks and alternate their use. Battery life and total capacity may suffer but it all depends on your priorities at the moment.

 

[Dick]

Thanks for all the input. Some extra points to help explain

our set up. We have 3 8d lead acid (1 year old) as our house bank. Equalized about 6 months ago. At first we are able to sit on the hook about 3 days before a charge is required. (12.2 volts) But after several days on the hook that starts to drop , and after a month I must recharge every day. (Benny, I've never heard of the theroy that a battery bank is too big. Thats a new one!!) It takes between 1.5 and 2.5 hours to re charge. The time difference depends on weather I'm running the water maker at the time ( Spectra Newport 400gpd).

The Xantrex does meaure the voltage at the battery, and I've double checked it with my VO meter and it is spot on. And again Xantrex says the system is working correctly. Sounds like I'm headed to solar pannels.

Again thanks for all the input.

 

[trontek]

Battery charging

Have I misunderstood some text that I found that says that we do not put electrons into a battery during charging but that the charger pulls them from the positive plates(which is why the charger voltage has to be higher than the battery voltage[since they tell us electrons travel from negative to positive] and that the chemical action within the battery generates the electrons and causes them to be available at the negative plates. It stated that, once enough electrons were "piled" up on the positive plates, there was no longer a difference in potential and the battery is "discharged"....?

Jim

 

[Don S/V ILLusion]

Jim

What voltage does is push the reaction by moving electrons from one pole inside the battery to the other. The actual metals and electrolytes used control the voltage of the battery -- each different reaction has a characteristic voltage. For example, in one cell of your boat's lead-acid battery:

The cell has one plate made of lead and another plate made of lead dioxide, with a strong sulfuric acid electrolyte in which the plates are immersed.
Lead combines with SO4 (sulfate) to create PbSO4 (lead sulfate), plus one electron.
Lead dioxide, hydrogen ions and SO4 ions, plus electrons from the lead plate, create PbSO4 and water on the lead dioxide plate.
As the battery discharges, both plates build up PbSO4 and water builds up in the acid. The characteristic voltage is about 2 volts per cell, so by combining six cells you get a 12-volt battery.
You charger merely controls the rate at which this occurs.

 

[trontek]

Why then does the charger potential

have to be higher than the rated battery voltage? Is the electron flow toward the charger or away from it? could this flow be shown with a meter in the positive lead between charger and battery? My fairly smooth brain needs more wrinkles....

Jim

 

[Don S/V ILLusion]

Jim

I don't want to (further) side-track this discussion. Search on info related to battery chemistry and see what you can find after which, you could always start a new post if you still have questios

 

[GuyT]

Push or pull ??

It all depends on your perspective

If I am behind you, I can push you.
If I am in front of you, I can pull you.
Regardless of termology, the net effect is the same - you moved.

Chargers push electrons from the chargers perspective.
Electrons are being pulled from the plate from the electrolytes perspective.

It all depends on which side of the plate your standing on.