Author Topic: adding batteries  (Read 5976 times)

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Mary B

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adding batteries
« on: December 18, 2013, 01:41:03 AM »
My current battery bank is about 14 months old, I just got a small inheritance and can afford to double the size of my battery set. Currently have 8 US Battery 2200XC golf cart. I was quoted about $900 for 8 more of those or about $1300 for 4 Trojan L16's.

Can I safely parallel 8 more golf cart bats with what I have or should I go with a second battery bank? I have 2 charge controllers and can go either route. Second bank would run fridge and freezer mainly. Maybe some kitchen/pantry lighting

Frank S

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Re: adding batteries
« Reply #1 on: December 18, 2013, 02:08:13 AM »
MaryAlana; I might ask a question if I may because I am getting ready to double my bank size as well.
 First off in the past 14 months do you have an idea of how many deep cycle discharges your bank has endured?
 How about short charging cycles where your bank did not reach full and remained there for a period of time.
 DO you have any idea of your banks state of discharge capacity in amp hours currently compared to when it was new?
  This might help you determine the direction you would be better off taking.
 My bank is 9 months old and has had not less than 80 discharges to the point that my inverter kicked off due to low SOC Each time it has done this I made sure to run my generator and battery charger in conjunction with the input form my array to bring the bank up to full ad held it there for a few hours. even though I felt I may have been burning diesel needlessly at the time
 Through out the summer at least twice a week I made sure the bank topped off .
 I have noticed though that with these short days I must run the generator most every day in the evenings or my bank will not power everything through the night and have enough left over for morning coffee if the fridge starts up  before the brew cycle is complete. If we were to wait until the sun hd been up for an hour before coffee time then the bank will make it .
 My system is only on 12 v nominal so what I plan on doing is remove the current bank from circuit and run the new bank while I check each of the older batteries individually . maybe even get  desulfater "spelling" and run that before reconnecting them to the system. They  appear to still be in great shape I just want to make sure , because like you I can just as easy run a split system but I would rather have a single system with multiple chargers.
I live so far outside of the box, when I die they will stretch my carcass over the coffin

birdhouse

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Re: adding batteries
« Reply #2 on: December 18, 2013, 10:55:32 AM »
if i were either of you, i'd add to the existing bank.  it's really nice (easy) to have all your Ah in one place.  less rigging around and switching ect.  but i'm sure there are advantages of having two banks as well. 

@mary-  i certainly wouldn't mix l-16's with you golf cart batts.  they typically take a higher bulk voltage and equalize as well.  BUT, if you could potentially get even more l-16's in the nearish future, it might be worth going dual bank, and the golf cart batts could become the smaller older bank once even more l-16's were purchased. 

i started with four trojan t-125's.  added four more about a year later.  they play well together.  however, i never once had the inverters LVD kick out.  i try to keep them more full than that.  my batts are also at a vacation spot, so they only get cycled ~40-60 times a year. 

adam


dbcollen

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Re: adding batteries
« Reply #3 on: December 18, 2013, 12:47:21 PM »
I started out with 8 rolls s460s, a year later I added 8 rolls s530s, and another year later I added 8 deka l16s. they are all working well together 8 years after the initial install. They are 8 series, 3 parallel for 48v. All gravities come up evenly, and they still have good capacity.

thirteen

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Re: adding batteries
« Reply #4 on: December 18, 2013, 01:21:18 PM »
I would check each battery now before adding others to it. If one by chance does not test well you could deal with it. I agree with birdhouse on the batteries.  Unless you have had problems with your batteries adding to them should be ok. If it was 3 years on them I would be extra concerned about longevity of the first set dragging the newer set down to an early death.
  The ones I have now will be used in a small workshop area next to the house. There they will be used about 6-7 times a year mainly during wood cutting. They are a mixed set and only one is a deep cycle battery and two are 2 years old the others are 4-6 yrs as a guess. Freebies. Just an idea to consider.  13 
MntMnROY 13

Mary B

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Re: adding batteries
« Reply #5 on: December 18, 2013, 02:32:08 PM »
Very few deep discharges, I rarely drop it below 70% maybe a dozen times to 50%. Otherwise they are acting like the day I installed them.I know newer batteries will charge different and that the system will somewhat compensate for it to a point. I doubt I will add onto this after this point, 4 strings in parallel is pushing it.

kitestrings

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Re: adding batteries
« Reply #6 on: December 18, 2013, 03:05:44 PM »
I agree with Adam.  I'd add them.  They're are barely broken in.  ~ks

Flux

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Re: adding batteries
« Reply #7 on: December 19, 2013, 04:25:31 AM »
As long as they are all good and of similar type paralleling usually presents no problems.

I don't expect you to have any trouble in this case.

The same does not hold good for series or series parallel banks.

Flux

john8750

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Re: adding batteries
« Reply #8 on: February 25, 2014, 01:16:12 AM »
Hi
I use eight 6 volt used golf cart 205's wired 4 pairs series and then in parallel to make a 12 volt system.
A 60 amp CC works good, I only have 600 watt about 35 amp max charging current.
I got the batteries for free. Seems to work very well.
Don't know about mixing new with used.

John Smith
Keep the fun in it. Give me sun light.
John Smith

Mary B

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Re: adding batteries
« Reply #9 on: February 25, 2014, 03:45:44 PM »
John I am adding 8 more batteries to my existing 8 that will be 2 years old by the time I get the second set of solar panels installed. I will have 2,400 watts of solar feeding 16 batteries. Looking to add a small wind generator that can get me 100 watts in 20mph winds as a secondary system to float the batteries but that will have to wait for more cash flow. Unless someone has a used 12 foot mini windmill they want to get rid of...

john8750

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Re: adding batteries
« Reply #10 on: February 25, 2014, 05:40:50 PM »
That's cool. I normally see high winds this time of year at my place, not this year  :(
I have 600 watt's on the roof. Would experiment with the wind, if there ever is any again. This is just for my hobby shop, about 350 watts max and about 20 hours a week. I don't use all the power I make.
Make sure all your batts are up to voltage. Might disconnect the charger and run the batts normally for a while, then check voltage. Look for one with less voltage than the others. I have had good luck with the used batts I get for free.
 Seems you have a good set-up.
 Keep the fun in it.......   :D

John Smith 
Keep the fun in it. Give me sun light.
John Smith

ChrisOlson

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Re: adding batteries
« Reply #11 on: February 25, 2014, 07:26:12 PM »
John I am adding 8 more batteries to my existing 8 that will be 2 years old by the time I get the second set of solar panels installed. I will have 2,400 watts of solar feeding 16 batteries. Looking to add a small wind generator that can get me 100 watts in 20mph winds as a secondary system to float the batteries but that will have to wait for more cash flow. Unless someone has a used 12 foot mini windmill they want to get rid of...

MaryAlana, I have strong doubts that a 100 watt mill will produce enough energy to float even eight 2200XC's, much less 16 of them.

You cannot parallel Trojan L-16's with your 2200XC's.  US Battery has pretty specific recs for charging with a two-stage charger that does not match Trojan's recs



You can parallel eight more 2200XC's with no problem, with a few caveats.  As I'm sure you're aware, US Battery uses a high-specific gravity electrolyte in the XC (Xtra Capacity) batteries and they will hit 1.300 SG with over-charging, which is not good.  1.285 is where they should be cut off or they will have actually less capacity being over-charged.  With strings of different age I'd install a battery monitor like a Trimetric on each string as a monitoring tool to make sure that the strings of different age are exiting absorb at the right amps.  The older ones that have been cycled will take more amp-hours than the new ones during absorb.  This will cause the new ones to be over-charged and reduce their capacity and shorten their life.

Any other type of battery you can parallel just about anything with anything.  But the US Battery XC-series are susceptible to damage if continually over-charged (note their 3%C absorb amp exit vs the industry "standard" 2% C exit current).

Call their tech support if you have any questions.  I have talked to them on L-16HCXC batteries for our yacht a couple of times and they have excellent tech support there - absolutely the best tech support I have ever talked to at any battery company.

ChrisOlson

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Re: adding batteries
« Reply #12 on: February 25, 2014, 08:09:44 PM »
Another hint that might save you a few bucks; all of Interstate's industrial batteries are manufactured by US Battery.  Interstate buys them by the train load and due to their good price they get on wholesale and their retail distribution network being so efficient on shipping costs, you can usually get the same battery from your local Interstate dealer for less money than it will cost from a US Battery retailer.

The Interstate L-16HCS is the same as the US Battery L16HCXC.  It is 420ah @ the 20hr rate, 1.285 SG.  We got these for our yacht:



They were $258 each from our Interstate dealer.  In my opinion, they would be a better match to your 2200XC's than another string of 2200's.  The reason is because the L-16 is much taller (they're like 2 feet tall) with thicker plates than the 2200's.  So they are less susceptible to SG's ending up at 1.300 with over-charging.  A new set of L-16's from US Battery (or Interstate Battery) would probably be a better match to your cycled set of 2200's in a parallel configuration.  These big L-16's are not near as finicky as the lighter duty golf cart batteries.

These are all of Interstate's batteries that are manufactured by US Battery - they prefix the part# of the battery with "U" although the battery model number (like L-16) will not have the "U" prefix):
http://www.batteries-faq.com/activekb/categories.php?categoryid=5
« Last Edit: February 25, 2014, 08:21:59 PM by ChrisOlson »