Author Topic: Battery Equalization  (Read 4614 times)

Fred Brooks

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Battery Equalization
« on: February 20, 2021, 02:16:55 PM »
   Now that we are beginning to see light at the end of the tunnel, we may want to consider visiting our coach so we don't experience any surprises. One of the more common situations will be the house batteries. For a lot of us they have been sitting dormant for over a year. Even though Beaver owners are the smartest on the planet, we should check our house batteries out even if the coach was plugged in or solar charged.
   Deep cycle batteries will leave a small sulfate deposit on the lead plates over time and the acid mixture will stratify from sitting too long. After checking water levels, and charging them up to "float then full" I would suggest that you give them a "hydrometer test" to see what state they are in. A fully charged lead acid battery should read 1.265 specific gravity (at 80 degrees). You can purchase a hydrometer for under $10.00 at any NAPA parts store. If your test is less than specified and you have not "equalized" your batteries recently, here is how you can do this yourself. In the Inverter/charger owners manual under "charging", you will find Bulk, Absorption, Float, then Equalization. Enclosed is a picture of how I do it to keep the process under control. This sequence will make the batteries boil a little as the voltage rises. Read the instructions and initiate the process from your Inverter/charger remote panel. After you are done, wipe down the batteries with baking soda solution then clean and protect the terminals. Doing this per your instructions will extend your house batteries life. Happy trails to all of us. Fred
Fred & Cindy Brooks
2000 Marquis, Jasper
C-12 Wild Cat (U of A)
2014 Honda CRV
Proverbs 3: 5 & 6
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Eric Maclean

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Re: Battery Equalization
« Reply #1 on: February 20, 2021, 04:42:06 PM »
Fred
Equalisation is a great idea to help equalize all the cells in a given battery bank but you should keep an eye on the chassis batteries while doing it if you have an Echo charger or some sort of battery combiner as often they will combine both battery banks at higher charge voltages and the chassis batteries are usually of a different age or even different type of batteries .
This can sometimes lead to over charge damage to the chassis batteries depending on the equalisation duration and voltage.
The chassis batteries need to be included in the electolite level check and should be monitored for signs of over charging
 ( excessive boiling or sulpher smell) during equalisation.
I personally have seen several chassis battery sets boiled  dry from lack of maintenance and a couple of good equalisation charges.
My coach has 4 x 6 volt flooded lead acid golf cart batteries for the coach and a pair of maintenance free 31S chassis batteries as many of these coaches do
The problem arises from the miss match of battery type as they may have different Internal impedence or resistance values which makes the bank with the lower impepence value excepts the charge much more readily than the other bank leading to over charging of the lower impedence batteries.
This is the same reason you should not mix new and old batteries in a given battery bank.

I don't want to confuse the topic I still believe in equalisation of the coach batteries because as you said it will help extend their life. Just be aware of the chassis batteries and the possible effects on them if they are combined  with different types of batteries during equalisation.
Hope this helps
Eric
1997 Patriot Yorktown
3126-B
2009 Chevy HHR
Roadmaster falcon tow bar
Demco Air Force one tow brake.

Fred Brooks

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Re: Battery Equalization
« Reply #2 on: February 20, 2021, 05:40:15 PM »
   Eric, Good point and thanks for sharing as I agree with you. What I forgot to mention is you can take the Echo charger out of the loop by removing the fuse from the yellow holder with the red wire with the yellow tracer (chassis battery charge line) until you are done. Fred
Fred & Cindy Brooks
2000 Marquis, Jasper
C-12 Wild Cat (U of A)
2014 Honda CRV
Proverbs 3: 5 & 6

Bill Lampkin

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Re: Battery Equalization
« Reply #3 on: February 20, 2021, 05:43:14 PM »
Our coach has the 'Bird' relay-doesn't that keep the two battery banks separated if both are fully charged? Correct me if I don't have this right.
2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
525 hp C13

"Goin where the weather suits my clothes..."

Eric Maclean

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Re: Battery Equalization
« Reply #4 on: February 20, 2021, 07:15:02 PM »
Bill
The B.I.R.D  or bidirectional isolator relay delay is actually the electronic module which operates the isolator relay/solenoid we commonly refer to as the bird
the electronics are set up to keep the two battery banks seperate to preserve the chassis batteries from being depleted when drawing down the coach batteries while dry camping. the BIRD electronics monitor both the chassis battery side of the relay and the coach battery side of the relay and when either side shows a charge voltage say from the engines alternator on the chassis side or from the inverter or even solar on the coach side the electronics turns the relay solenoid on connecting both battery banks together so they can be charged all together. The e!ectronics have a delay built in to allow the charge system to stabilize before connecting the second battery bank to avoid voltage pull down which could cause the relay to drop out or bounce or chatter.
As long as there is a good charge voltage present on either battery bank the solenoid should be closed connecting the two battery banks together.
Hope this helps
Eric
1997 Patriot Yorktown
3126-B
2009 Chevy HHR
Roadmaster falcon tow bar
Demco Air Force one tow brake.

Bill Lampkin

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Re: Battery Equalization
« Reply #5 on: February 20, 2021, 08:47:49 PM »
So I have sealed chassis batteries and flooded (gc2) batteries for the coach. Do I have to disconnect the chassis negative cable while equalizing the coach batteries?
2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
525 hp C13

"Goin where the weather suits my clothes..."

Bill Lampkin

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Re: Battery Equalization
« Reply #6 on: February 20, 2021, 08:55:17 PM »
Maybe just turn off the chassis battery disconnect switch??!! Then equalize the house batteries!
2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
525 hp C13

"Goin where the weather suits my clothes..."

Fred Brooks

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Re: Battery Equalization
« Reply #7 on: February 20, 2021, 10:14:33 PM »
  Bill, Not sure if you have the Magnum or Xantrex Inverter/Charger. Either way their top off voltage at the end of the Equalize sequence is close to 16 volts. Because the "big boy solenoid" that Eric meant is what ties things together. I would disconnect the negative battery cable or use your meter to determine if your disconnect theory works. I would follow the recommendations of the Inverter/Charger owners manual. Fred
Fred & Cindy Brooks
2000 Marquis, Jasper
C-12 Wild Cat (U of A)
2014 Honda CRV
Proverbs 3: 5 & 6
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Gene Obie

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Re: Battery Equalization
« Reply #8 on: November 11, 2021, 02:46:54 AM »
Following up on an older thread. Another poster recently complained of a "Mystery Noise" under the bed and Fred suggested it might be inverter/charger cycling due to batteries needing an equalization charge. Turns out I just started getting a mystery noise near the bedroom that was waking me up at night- and it did indeed appear to be coming from the inverter charger. I had never done an equalization charge as I knew my batteries were due for replacement so didn't think it important. However, I looked up all the settings on the battery manufacturer website, set up the charge parameters and did the equalization and it has stopped the cycling for now and hopefully until I get new batteries.

House batteries are wet cell and chassis AGM so I decided just to pull the control line from Big Bird controller to Big Boy relay and confirmed chassis batteries did not receive higher voltage so that worked for me. Also, turned off all 12V breakers in the coach and didn't use any 12V accessories during the equalization to be safe.

So thanks to Fred for his suggestion. Seems I learn something new every day.
-Gene

2005 Beaver Marquis, Ruby 40, C-13 Cat 525HP, Allison 4k
Towing 2018 F-150
Washington
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Bill Lampkin

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Re: Battery Equalization
« Reply #9 on: November 11, 2021, 03:12:27 AM »
i had a mystery clunk also-Turned out to be a bad battery temp sensor; unplugged the temp sensor from the inverter and the 'clunk' went away. Later, I pulled the modified sine wave inverter and replaced it with a pure sine wave inverter to keep my new residential fridge happy. New temp sensor came with the inverter, all is humming along.....
2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
525 hp C13

"Goin where the weather suits my clothes..."