Equalization

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BaltimoreLurker

BaltimoreLurker

Curmudgeon
Joined
Oct 8, 2007
Messages
2,775
Location
USA
Vessel Name
Moon Dance
Vessel Make
1974 34' Marine Trader Sedan
The spiffy new Xantrex XC3012 charger has seemingly been performaing well for the past month. So now I decided to equalize the batteries.* Checked the specific gravity of each cell of the two 8D's in Bank 1. All read between 1.265 and 1.275 at 84 degrees on the IR gun.* All seemed right with the world.* I put the charger in the Equalization mode on Bank 1 and I got the expected indications on the monitor.* But she dropped out of equalization mode after about 3-5 minutes and went back to the routine monitoring and into Float mode.

I put it back in Equalization and it dropped out again after a few minutes.* Did it again and quickly checked the voltage at the terminals of the batts, which read 13.1V. Not the 14V - 16V I was expecting.* She dropped back into Float mode and as the charger cycled between the 2 banks the voltage on Bank 1 varied between 13.1 and 13.4 (as bank 1's turn came around)

Some background:* I have 2 banks of two 8Ds.* I have no idea of the age of the batts.* This is the 2nd season with the boat for me, no telling how long they were in the boat before then.* The reason I have a new charger is because I screwed up, left the master switch on after a trip and didn't come back to the boat for 2 weeks.* They appeared to be "dead" as even the bilge pump wasn't working and I had high water in the bilge.* Hooked up the shore power and the bilge pump kicked in and did it's job.* I had an old ferroresonant charger that I didn't trust to be on shore power if I wasn't around for more than a few hours.

I'm going to try Bank 2 later today.* And contact Xantrex.

Anybody here have any ideas?

Thanks,
Darrell
 
Doh!* Never mind.* Like my daddy always says, "If all else fails, read the instructions."* So I read them again.* And again. And again.* And finally I realized I wasn't pushing all the appropriate buttons correctly.* Once I did, she immediately started pumping in 15 amps at 15.5V.* That's more like what I expected to see.

- Darrell
 
"15 amps at 15.5V."

About right , usually the equalizing start is about 1% of capacity.

Should get warm , as stirring the electrolite is part of the process.
 
Oh, they were bubbling away merrily.* Eventually the voltage got up to 15.9V.* After 2 hours of cooking the temp was still below 90 degrees.* It was taking a while for the heat to soak through to the outside of the case.

Bank 2 only got up to 14.5V at 15amps.* I'm wondering why the difference.* Maybe higher resistance to breaking down the lead sulfate on Bank 1?* I can convince myself this makes sense as Bank 1 is the "starting" battery bank and is where the alternator is wired to.* So in the past maybe it's seen more very shallow discharges and incomplete recharges.

- Darrell
 
If bank 1 is the start it probably got GREAT recharges , as starting seldom takes even 1% of a batt.

Batt 2 set is probably lower V as IT has the sulfation from deep discharges , waiting half dead to get recharged , and only getting to 100%SOC in the slip , or on transit of 8 hours or so.
 
I believe you are correct, sir.* Once I put the hydrometer to Bank 2 I realized how bad a situation I'm looking at there.* Deeply discharged and low on electrolyte to boot.*

Bank 1 seems to be about as good as it gets. Bank 2 is in serious need of help.
 
"Bank 2 is in serious need of help."


Equalize once a week, have distilled water aboard.

If you ever were going to get one of the pulse setups , now is the time.
 
I'm not ready to try one of the pulse gizmos yet.* The first few hours of cooking Bank 2 increased the capacity of the cells (based on the SG readings) from just over 25% to somewhere between 50% - 75%.* I'm feeling good about this so far.* I cooked them again for a few hours yesterday.* I'll let them soak and equalize internally for a day or so and then check the SG again to see how we're doing.

I've learned more about battery chemistry in the past few weeks than I ever knew existed.
 
The jury is still out on the pulse units and to date their is no real science that they do much. You need a charging system capable of equalization and that will carry a float charge that will not overcharge the batteries and will deliver the required charging for both banks. All of your batteries need an equalization charge on a regular basis, once a week if possible or at least once a month. Eventually this kind of maintenance will bring all of your batteries back, providing there has been no cell damage. BTW, I am not a big fan of Xantrex. Chuck
 
Capn Chuck wrote:
BTW, I am not a big fan of Xantrex. Chuck
Click to expand...
The only complaint I have so far is that the charger isn't as "Smart" as I thought.* Equalizing batts as badly damaged as mine is a time consuming exercise and the Xantrex charger shuts equalization off after 1 hour so you can check temps and water levels.* I wish I could adjust that to a few hours at a time.

- Darrell
 
"Eventually this kind of maintenance will bring all of your batteries back, providing there has been no cell damage."

Sorry but there is ALWAYS cell damage the lead is allowed to slough off , and falls into a space below the active plates.A non ending slow loss of capacity.

Part of the design difference between starts and house.

Starts are thin plates with mucho surface area that foll the case,
, the house thicker lead and space in the case for the results of aging deterioration.
 
BaltimoreLurker wrote:

*
Capn Chuck wrote:
BTW, I am not a big fan of Xantrex. Chuck
Click to expand...
The only complaint I have so far is that the charger isn't as "Smart" as I thought.* Equalizing batts as badly damaged as mine is a time consuming exercise and the Xantrex charger shuts equalization off after 1 hour so you can check temps and water levels.* I wish I could adjust that to a few hours at a time.

- Darrell

*

Darrel, I understand your issues with the Xantrex and the timeout on the equalization. Your initial post that it is* brand new means you have not yet put any miles on it. I hope that it does not become a problem in the near future but we have replaced and removed for repairs,* too many Xantrex units, not only battery chargers, for me to even suggest someone go to these units as replacements or upgrades. That is not to say every unit will fail and perhaps yours will be fine for a long time. But the percentage of failures for many Xantrex products is just way too high in my opinion. Chuck

*
 
Capn Chuck wrote:
I hope that it does not become a problem in the near future but we have replaced and removed for repairs,* too many Xantrex units, not only battery chargers, for me to even suggest someone go to these units as replacements or upgrades. That is not to say every unit will fail and perhaps yours will be fine for a long time. But the percentage of failures for many Xantrex products is just way too high in my opinion. Chuck
Click to expand...
Chuck:

I hope this one runs!* I did a bit of research and did see that there are some problems with Xantrex.* But overall, it appeared to be closest to what I wanted/needed.* And anyway, I don't know that this is the last boat for me.* When originally purchased I intended for it to be my "practice" boat for maybe 5 years or so.* I wanted to get familiar with all the issues associated with a small power boat as my previous experience was on a very simple small sailboat.* The power boat has way more, way more complex systems to deal with.* I've already worked through prop, propshaft, cutless bearing, engine mounts, basic diesel mechanics, some of the fuel/filtering, some of the electrical ..... on and on. Haven't even touched the cosmetics yet, not to mention the traditional MT wet cores.* Much to learn!* I taught myself to sail - how hard can this be? (Famous last words!)

- Darrell






*
 
"The power boat has way more, way more complex systems to deal with."

Nothing you mentioned would not be on a sail boat .

The motor boat complexity comes from the "higher" (their opinion) standard of living.

Sailboats have 60 inch Plasma Tv's, air cond , deep freezers and drawers of gadgets ., along with complex secondary electrical requirements . NEMA 2000 so your sat nav can talk to the 3D depth sounder is great , for only those who like visiting dealers.

The LESS you have to fix ,maintain, repair , jury rig , replace , the more time there is to enjoy the cruise!

This is perhaps a minimalist view , but in places like the Bahamas a foot painted 12ft pole is far better to find an overnight spot than forward scanning sonar.

Boats need not be holes in the water , if the owner decides NOT.
 
But they weren't on my sailboat!* An 8 HP Yamaha O/B, a porta-pottie, an igloo cooler, a VHF radio, a line & clamp tiller-tamer, one 12V battery, some tell-tales and a weather vane* .... that was pretty much it!

I wanted a bigger boat but not bigger sails.* The ladies wanted an enclosed head and hot, running water, a place out of the sun, etc.

A friend of mine, a lifelong sailor & power boater, on his first trip on "Moon Dance" was blown away.* He said "Man, this is like being on a sailboat.* Except I can see and it's a lot less f'ing hassle."* True 'dat!
 
OK, this little project is done for now.* According to the hydrometer I have achieved significant improvements.* I'm still a little foggy on how all this really works but it appears that I have moved my available capacity from something like 25% to around 85%.* At least based on the SG readings.* So, if there is that much more acid in the cells I have to guess it came from breaking down the sulfates & restoring lead dioxide; seems the process worked as advertised.*

According to Calder there are a couple simple load and capacity tests I can run to see if I really have anything.* I'll try to get to them this weekend.
 
Good news. At this point with regular maintenance you should get decent service from your battery banks. At 85% I doubt you are going to get a whole lot better considering what the batteries have been through. But you will have to monitor them and stay on top of maintenance. Good Luck. Chuck
 
ralphyost wrote:

You didnt mention how you are taking your specific gravity readings.
Calder specifically warns that SG readings must be taken when the battery is at rest, not being charged, and not being discharged. The following web site provides similar discussion
http://www.rpc.com.au/products/batteries/accessories/hydrometer/hydrometer_faq.html
Click to expand...
Fully charged, no load, at rest for at least 24 hours - but in "Float" mode.* Is Float at Rest?* Hmmm, reading the article makes me think that maybe I should shut off even the float mode and let them rest.* However, if I'm reading correctly the SG may be
even a bit higher after I take it off float.




*
 
You really should be taking the readings with the batteries at rest with nothing, including the charger, on them. Chuck
 
"You really should be taking the readings with the batteries at rest with nothing, including the charger, on them"


AND you must wait 24 hours for the test to be valid.

Folks in a hurry will get rid of the higher surface charge with a tail light sized bulb and about 10 min of light. Do not test till after the bulb is disconnected.
 
After three years with Pulsators, my house 4 D battery has to be replaced. I just replaced four 6 volt house batteries after four years also fitted with Pulsators. I have an old fashioned "dumb" charger so that may be why the Pulsators do not work. Every time I think about installing a "smart" charger I am discouraged by all the negative comments for all the different makes of chargers. Hey, at least I know what I got.
confuse.gif
 
I have to replace a 4 D house battery and I would like to go with a battery I can physically handle. Capacity is no problem as my house bank is comprised of four 6 volt golf cart batteries and the 4 D. Starting batteries are a separate bank. Can I put in a smaller*size battery without screwing up the system?
 
The current choice for starts is the size 31.

These starts are used on many large trucks , where the CCA is huge in winter, may take a pair for them.

Unfortunatly LEAD is what does the work, so a smaller lighter bat set will not have the capacity of the old huge 8D or 4D

The Trojan L -16 , if you have the height and is paired for 12V.Being 6 V batts they are more efficient per footprint as the internal seperation is less , more lead.

If you have the bucks for a REAL, 150-200A recharge setup , the Odesy thin plate deep cycles might be worth the bucks as the useable amps per discharge can be higher.

These can be brought down to 30% and if quickly recharged do not suffer fewer cycle life.

You will usually (on the hook) cycle wet batts from 80% down to 50% (of 20 hour rate).

The special thin plates may go from 90% down to 30% , a double of useful discharge with little more charge time.

Depends how you cruise , how you value no noisemaker time , and how many boat bucks you can"invest".

FF
 
I pulled out the 4 D battery and will replace it with two 6 volt golf cart batteries. This will give my house bank six golf cart batteries working together. I never was comfortable with putting a 4 D battery in parallel with six volt golf cart batteries, but that's the way the boat was set up. Hey, it only took me ten years to figure it out.
biggrin.gif
 
You may have problems with the age difference of the house set.

The old way of keeping banks ( Rotary 1-2 switch) might be advisable ,

although today the Big Bank ,all used at once is the modern house management scheme.

FF
 
I have a Xantrex Inverter Charger (3.0) and is brand new. The other one took a dump after just 2.5 years of use. Called the company and they said, sorry, out of warrantee. Buy a new one.

I was told by a friend of mine that equalizing the batteries slowly damages them. I see some recommendations in this thread of equalizing once a month.
Does equalizing slowly damage or diminish the wet cell battery?
If not, how often should one "equalize"?
 
According to the very experienced marine electrical shop we use, how often you equalize will depend on your battery setup and how you use your boat. We use ours year round but have very low electrical demands on the system. Up till now the boat has had its stock electrical system consisting of two 8D lead-acid batteries (plus a 4D for the generator).* We are changing this setup next week but the system operation and usage will remain unchanged.

Our batteries are charged continuously via a 3-stage charger (with two echo chargers) on a Heart Freedom 25 inverter/charger we had installed some ten years ago Based on our battery setup and usage it was recommended that we equalize the batteries once or twice a year, which we do (usually once). The owner of the shop said some people recommend equalizing more often but in all the years his father and now he have been in the business he has not found more frequent equalization to be beneficial to a system like ours given our usage.

So there would appear to be no "one size fits all" answer to your question. I would suggest you do as we did, and get advice on equalizing from a reputable and experienced marine electrical shop, preferably one familiar with your boat's battery setup and how you use its electrical system.
 
The service guys plug in the charger for a few days at least twice during that period. I top off the batteries in the Spring and equalize

In the cold the self discharge is a bit lower , but a new battery will loose about 1% per day , an old batt almost 3% PER DAY.

AS the bats age the number of times the set needs to be recharged in increases.
 
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