battery equalisation charge

[Conachair]

I wasn't even going to mention temperature that's a whole other can of worms.........

But keep it coming, I learn more here than I ever did at school!!
Back to the start, of considerable interest to me as I´ve just bought 4 x us battery 2200´s. I have 2 regulaters, an hrdx which i can switch on or off line and a old fixed 14.2v unit with a power sump bar heater type thing. Now would it be possible to increase the voltage at which it cuts in by placing a couple of big diodes in line - would that mean that the reg would see 1.4v less than at the battery and take the cut in voltage up to 14.2 + 0.7 + 0.7=15.8v ?? Presumable if that would work the diodes would need to be pretty hefty to take full load of the wind gen and solar on a windy sunny day. Any thoughts or another workaround anyone?

TIA

 

[Gumpy]

But keep it coming, I learn more here than I ever did at school!!
Back to the start, of considerable interest to me as I´ve just bought 4 x us battery 2200´s. I have 2 regulaters, an hrdx which i can switch on or off line and a old fixed 14.2v unit with a power sump bar heater type thing. Now would it be possible to increase the voltage at which it cuts in by placing a couple of big diodes in line - would that mean that the reg would see 1.4v less than at the battery and take the cut in voltage up to 14.2 + 0.7 + 0.7=15.8v ?? Presumable if that would work the diodes would need to be pretty hefty to take full load of the wind gen and solar on a windy sunny day. Any thoughts or another workaround anyone?

First thought on this is that the forward voltage of a diode changes with the current passing through it. So at low current it will have a different value to high current..........so the voltage will be wrong at least 50% of the time.

 

[ColinR]

But keep it coming, I learn more here than I ever did at school!!
Back to the start, of considerable interest to me as I´ve just bought 4 x us battery 2200´s. I have 2 regulaters, an hrdx which i can switch on or off line and a old fixed 14.2v unit with a power sump bar heater type thing. Now would it be possible to increase the voltage at which it cuts in by placing a couple of big diodes in line - would that mean that the reg would see 1.4v less than at the battery and take the cut in voltage up to 14.2 + 0.7 + 0.7=15.8v ?? Presumable if that would work the diodes would need to be pretty hefty to take full load of the wind gen and solar on a windy sunny day. Any thoughts or another workaround anyone?


TIA

Before you embark on that, I have emailed US Battery again to try and get a more definitive answer on charging. This thread is very interesting and I have learnt quite a bit but my main concern is quite specific and limited i.e. will this make of battery charge properly or not with my charging setup. I will post anything relevant that I hear back from them. Colin

 

[Conachair]

Before you embark on that, I have emailed US Battery again to try and get a more definitive answer on charging. This thread is very interesting and I have learnt quite a bit but my main concern is quite specific and limited i.e. will this make of battery charge properly or not with my charging setup. I will post anything relevant that I hear back from them. Colin

Thanks Colin. Plenty more on the jobs list before I get to that anyway

 

[ColinR]

Thanks Colin. Plenty more on the jobs list before I get to that anyway

Here is the response from US Bat. Tech help:

'Your battery is not getting fully charged at 14.8 Volts. You need to bring it up to 15.5 Volts and hold it at this Voltage for two hours for proper charge.
Or else, you can do the recommended equalization every 5 to 10 discharge / charge cycles and not less than once a month.'

Great. Any suggestions how to charge it at 15.5v?

Colin

 

[rivonia]

reply to Cervina and Conachair

Well this keeps going deeper and deeper especially as we are bringing in Temperature. At this stage I will humbly bow out. Why, well it was over 15 years ago when I did my intensive 5 day course on DEEP CYCLE BATTERY MANAGEMENT. It would appear that a lot of things have changed since then. Thanks for the discussions most help full

Peter

 

[Stu Jackson]

Here is the response from US Bat. Tech help:

'Your battery is not getting fully charged at 14.8 Volts. You need to bring it up to 15.5 Volts and hold it at this Voltage for two hours for proper charge.
Or else, you can do the recommended equalization every 5 to 10 discharge / charge cycles and not less than once a month.'

Great. Any suggestions how to charge it at 15.5v?

Colin

Colin, here's how I read their response: The Or Else is critical. It appears to me that their basic recommendation is to charge at a higher than normal bulk voltage. OR just charge "normally" and then equalise monthly.

That OR to me is a giveaway.

I believe their concept is to provide a little mini-equalisation every charge cycle, rather than equalising monthly (or regularly).

Oddly enough, they do not mention amperage, nor the "standard" bulk-absorption-float stages of "normal" charging.

Your boat, your choice. If it was my boat, I would ignore the 15.5 volts, and simply charge "normally" with the way most chargers are set up (save the one mentioned earlier that is software programmable) and equalise regularly.

I do not think you have any issues. This has been fascinating.

But I'll ask my friend on Saturday anyway and let you know.

 

[ColinR]

Colin, here's how I read their response: The Or Else is critical. It appears to me that their basic recommendation is to charge at a higher than normal bulk voltage. OR just charge "normally" and then equalise monthly.

That OR to me is a giveaway.

I believe their concept is to provide a little mini-equalisation every charge cycle, rather than equalising monthly (or regularly).

Oddly enough, they do not mention amperage, nor the "standard" bulk-absorption-float stages of "normal" charging.

Your boat, your choice. If it was my boat, I would ignore the 15.5 volts, and simply charge "normally" with the way most chargers are set up (save the one mentioned earlier that is software programmable) and equalise regularly.

I do not think you have any issues. This has been fascinating.

But I'll ask my friend on Saturday anyway and let you know.

thats what I have been doing (well not the equalising bit which would be a bit of a pain)and I've been getting approx half the expected use out of the battery before having to charge it again. Less than the smaller capacity leisure battery that I had before. Thats why I started investigating. Anyhow, thanks for the input everyone. Colin

 

[Stu Jackson]

Colin, not sure what you mean by "it would be a pain to equalise" unless you don't have a charger that does that. One of the possible reasons your bank is failing that way is because you haven't equalised. I figure you know that already...and reading your initial post, maybe your charger doesn't. If it doesn't, reread this whole thread, someone mentioned a "desulfinator," which from reports I've read on other sites, work pretty well. Here's one: http://forums.catalina.sailboatowners.com/showthread.php?t=115587 So instead of getting a new charger, try one of those puppies.

In the West Marine Advisor on battery charging (http://www.westmarine.com/webapp/wcs/stores/servlet/westadvisor/10001/-1/10001/Battery-Charging.htm), they write:

Equalization: This stage is used to prevent flooded lead acid batteries from aging prematurely, and is an optional, but frequently omitted phase. After the battery reaches the end of the acceptance phase, the battery continues to be charged at 4% of C until the voltage stops rising, usually around 15.5-16.2 volts. This forces the battery to its highest possible state of charge, boiling the electrolyte in a controlled manner and dissolving the crystals of lead sulfate that have collected on the battery’s plates. In industrial applications where maximum energy storage is important, this phase is done every charge cycle. In the marine environment, it is more likely to be done every 20-50 cycles to extend the life and capacity of wet batteries. Gel and AGM batteries should not be equalized. Since electrical equipment and light bulbs can be damaged by high voltage, the battery should be disconnected from all loads during equalization.

Maybe the red is what the manufacturer was suggesting. Industrial applications don't usually have voltage sensitive equipment like light bulbs and stereos, do they?

 

[ColinR]

Colin, not sure what you mean by "it would be a pain to equalise" unless you don't have a charger that does that.

I dont. Cheers, Colin

 

[Sybaris]

ColinR,

I don't think your batteries are failing because you haven't done the equalization because the seem to have failed far more than is normal. I have a Freedom charger with the possibility of running the equalization regime whenever I want but out of neglect and lazyness haven't done so for several years and have not noticed any adverse effect on my battery bank.

I also seriously doubt the advice given by the rep you have been in contact with. Like Stu said for example, how can you sell batteries to the marine market that need to be charged at 15.5V when most 12V rated equipment typically works in the range 12-14V.

My feeling is that you have another problem with your batteries. One thing that will cause batteries to wear out very quickly for example is if you often discharge below 50% charge.

A good 3 stage charger should do the job, but make sure you size your battery bank properly. A good source for all of this is the Nigel Calder book. In fact I think every boat should have his book as a minimum requirement.

Per

 

[Stu Jackson]

...good 3 stage charger should do the job, but make sure you size your battery bank properly. A good source for all of this is the Nigel Calder book. In fact I think every boat should have his book as a minimum requirement.

I agree with that suggestion, but not all 3 stage chargers have that separate equalization phase. My Freedom 15 combined inverter charger that I installed in 1998 has the feature, but can only be triggered into that by the use of the Link 2000 monitor that I bought but took all of 8 years to get around to installing! Set a new procrastination record!

Re: Calder's: When we bought our boat, it was July 1998, a week before we were supposed to go on a house exchange to Chipping Norton. Bought the book, fixed the overheating on our new-to-us boat by servicing the heat exchanger in those few days I had left before the trip, and for the four weeks we were in the UK I read the electrical section of the book until it wore out! Great resource, and I think the 2nd edition is superior to the newer version.

Another fantastic and important resource is Ample Power's Primer, download-able from their website: www.amplepower.com. Great battery information and a multitude of different wiring diagrams for all tastes and sizes! Click on the Technical Documents tab. Saves a LOT of incorrect information from being inadequately applied.

Also recommends equalisation and breaking in new batteries. "What?," you say. Why not just read it?

For Colin: either your batteries are toast, your charger is wonky, you need to equalise or Nanopulse (I just ordered one based on my earlier post - I have both corresponded and spoken with Rich Stidger, a very competent fellow, about his system, and we also developed the Link "Gotcha" Algorithm post for those of you with battery monitors and fridges: http://c34.org/bbs/index.php/topic,4922.0.html).

Or you're just fine. Pretty much where you came in, isn't it. But pretty good help from many here.

I'm surprised no one asked you about what your hydrometer readings are. I would check them.

There was also a recent thread about battery monitors compared to adding more battery capacity. The general rule of thumb is if you've done an energy budget and your house bank is satisfactory, then the best thing you can do is get a monitor. It will at least tell you if your suspicions about the health and state of charge of your bank is correct. The two choices: more batteries or monitor? Been there, done that and I had a large bank (360 ah) and procrastinated on the monitor. I should NOT have waited. Most folk suggest this too. Why? See: Battery Acceptance (the thread wanders off to something else though): http://c34.org/bbs/index.php/topic,4787.0.html

Cheers

 

[ColinR]

Hi Per, Stu, the information was direct from the manufacturer in response to the question 'using a multi stage charger that is regulated to 14.8 v on absorption phase, will my battery get fully charged. Answer, no,it needs 15.5v. This information is on their website as well in contrast to other manufacturers who give the more usual 14.8 voltage. I think these batteries are used a lot for golf buggies, maybe they have a different charging setup.I do have monitors both for the sterling regulator and wind gen and a separate ampmeter. I have also done hydrometer tests regularly. It all shows that the battery never gets fully charged. The cranking battery is charged by the same setup and is always fullly charged. I dont think my battery is toast, its in good nick, all cells showing the same hydrometer reading, performs exactly to spec on discharge test when charged fully off the boat. I think I have to take seriously what the battery manufacturers are saying. After all it explains the symptoms I am getting. I have also read Calders book , very illuminating.

Cheers, Colin

 

[halcyon]

Answer, no,it needs 15.5v. This information is on their website as well in contrast to other manufacturers who give the more usual 14.8 voltage.

Quick bit.

Back in the old days we picked 14.2/ 14.3 volt for max charge voltage.

This was because above 14.4 volt, the battery voltage on charge goes up rapidly for little extra charge. Also an old battery may not reach 14.4 / 14.5 volt on charge, so could be a problem for OE boat builder and service issue. So 14.2/14.3 was a safe value, and gave over 90% recharge, so risk free.

To fully charge a battery you need 15.5 volt ( depending on type ), 14.6 volt will give around 95%, 14.8 will be say 98%, 15.5 100%.

So to gain the final little bit of capacity you have a lot of gassing, and water usage.

So you have the BULK of the charge before 14.4 volt, above that not much over 5% extra.

Equalisation was intended to equalise the chemical coversion rate through the thickness of the battery plate. The problem is that the charge when the battery starts to gass is not ideal for this to happen. So you end up with lots of gassing but little charge.

It's all down to the marketing department interpretation, and the sales litreature.

Brian