BajaNomad - battery replacement

battery replacement

baja43 - 3-20-2014 at 08:23 AM

Two families, with separate houses, share a long-existing solar system. Both families are vacationers. System has been running successfully for 15 years. Don't want to fix what ain't broken, but the batteries are really old and are dying off.
There are 11 separate panels, measuring 17' wide by 4' high, in total. I have no clue on the watts, as they are all different.
There is a Trace 2.5KW inverter.
There is an RV Power Products/Solar Boost charge controller (12/24 VDC 60 amp output); 36/48 VDC input..I have no idea what that means)
There are eight pairs of 6 volt batteries (Stowaway/Exide GC2) installed in Nov. '05
Can I just buy 16 of the Costco GC2 size golf cart batteries as replacement (about $100 each, out the door) and be done with it?
We are in the Colonet area; small, not fancy homes; our neighbors visit for a total of 30 days per year; we're there about 100 days per year.

larryC - 3-20-2014 at 04:17 PM

On a system like that, that has been running well for many years, I would just replace the batteries with similar batteries and yes the Costco batteries would be similar. Sorry, that's a lot of words just to say "yes".
Larry

willardguy - 3-20-2014 at 04:31 PM

they got good service out of those batteries

but I'd go with L16's and lessen the interconnections.

DavidE - 3-20-2014 at 04:53 PM

Check the production run date on the batteries. COSTCO purchases from several vendors and you do -not- want to mix battery origins. The label may indicate OEM origin. Top charge the newly installed batteries, recommended 5 amperes constant amperage until batteries reach 15.0 volts then terminate the charge. This will get them off to a good start.

Alm - 3-20-2014 at 11:15 PM

Yes.

Also, I would replace the charge controller with some of the equal power but the one that has a remote temperature sensor. Unless controller is mounted somewhere in the shed next to batteries and already has on-board temperature compensation. With freezing mornings and hot days in Baja winter, temp compensation is very desirable, helps to prolong battery life.

Bob and Susan - 3-21-2014 at 06:28 AM

first you need to know what voltage the inverter works at .. 12 ..24...48 volts

then I would buy AGM batteries for part time use...like you

just replace the batteries...clean the cables

and get 12v volt not 6 volt
if your budget is $1600 you can 8 nice 12v batteries that don't need "watering"

the new Trojans are failing here...
I wouldn't buy them because of their "history"

don't "over think it" for a system you'll only use 100 days a year

monoloco - 3-21-2014 at 06:55 AM

Quote:

Originally posted by Bob and Susan
first you need to know what voltage the inverter works at .. 12 ..24...48 volts

then I would buy AGM batteries for part time use...like you

just replace the batteries...clean the cables

and get 12v volt not 6 volt
if your budget is $1600 you can 8 nice 12v batteries that don't need "watering"

the new Trojans are failing here...
I wouldn't buy them because of their "history"

don't "over think it" for a system you'll only use 100 days a year

What would be the advantage of using 12v batteries? It seems like he would end up with a lot of parallel strings that way. It's better to design a battery bank to minimize parallel strings, the ideal battery bank would have just one sting of batteries in series.

larryC - 3-21-2014 at 06:59 AM

Quote:

Bob,
I'm impressed, the last I remember you hated AGM batteries

Baja43
Here is a link to a battery place in El Cajon where you can get new surplus 12v agm batteries for $75 each plus a core charge, so take your old batteries with you.
http://deepcyclebatterystore.com/cosmetically-blemished-batt...
Hope this helps
Larry

bonanza bucko - 3-21-2014 at 07:49 AM

I think you must learn a lot more about what you now have before you replace the batteries.

You need to match the charge controller's voltage to battery voltage. You can wire the new (or old) batteries to any voltage you want by reading up on the internet about that. Trojan Batteries and Rolls Surette Batteries both have good web pages for that.

You can probably get a lot more efficiency out of your system by investing ($300-$400) in an MPPT charge controller and then wiring your panels and batteries to take advantage of it. An MPPT charge controller takes the voltage of the panels at every 60th of a second and reduces that to the voltage of the batteries at the 60th of a second and converts the difference to increased AMPs which charge the batteries faster than if they were simply hooked up to the panels or through an old charge controller that doesn't do the MPPT trick-----not really a "trick" if you understand that Watts/Volts = AMPs, or V x A = W, or W/A=V. You want more Amps because Amps are power and power charges your batteries and gives your inverter the DC Amps it converts to AC amps needed by your wife to run her hair drier :-)

So you probably can see that wiring your panels for 60 volts and your batteries for 24 volts will produce an "overhead" of 36 V which will be converted to Amps by the MPPT charge controller at any give wattage then being produced by the panels.

Old solar panels are usually nominally 12 volt jobbies which produce something like 100 Watts. So one panel would produce 100W/12V=8.3Amps. But the "nominal" 12V panels can produce several volts on each side of 12--9 to 14 depending on how old and what quality they are. Typical Baja solar systems with panels that have been added over time that aren't matched closely as to voltage and wattage end up not producing what they should to charge your batteries and run your house during the day.

Investing in modern panels and matching them would most likely save you a lot of money in the long run. Modern panels producing 30V and 250 W (or 250W/30V=8.3A) are pretty common. I think if you had either 2 or 4 of them you would improve your solar power production.

I think if you study up on the Trojan or Rolls web pages you will conclude that an L-16 battery in 6 V is the best you can buy and wiring them up into a 24 V system would be good. A 24V system on the DC (charging) side of your system will require smaller wires than a 12V system because the amperage is lower at any given wattage---again W/V=A and VxA=W etc.

One thing to remember in all this is that the end result of all this is to produce DC power that your inverter then converts to the AC power your house needs. So read up on the net about inverters. Go look at Magnum Energy and their Magnasine inverters or look at Outback Solar for theirs. You will probably then conclude that you need a "sine wave" inverter that produces AC power with a full sine wave instead of a modified sine wave inverter. Modified sine wave power will produce noise in light bulbs and might not be liked much by such gizmos as computers.

All of the above is gonna cost a little. So be ready for that and then line up a bunch of friends who have solar systems that they have built for themselves and get them to help you. That's what I did and I am happy with the result. But, bottom line, you gotta study up some on the web. It's fun.

BB:-)

Alm - 3-21-2014 at 09:50 AM

If they just replace the batteries, new ones will be dead in a shorter time than the old ones, see below.

There is stuff that you have to do, and stuff that is desirable or recommended.

Replacing dying batteries is a must.

Cleaning contacts is highly recommended.

Having a charger with temperature compensation is highly recommended.

Getting AGM in place of 6v flooded is recommended, if your absence is long between 3-months visits, and the batteries are NOT floated/maintained during that absence, i.e. they are not connected to solar.

Why batteries will be dead in a shorter time - because your solar is now 15% less efficient than it used to be years ago, and I sense poor monitoring and maintenance of batteries all those years.

Bonanza Buck - people don't know what "36VDC input" is. Any more questions? Of course, MPPT and proper wiring makes system more efficient. But I think both families using this ~800W solar, have and run generators few times a week, if not daily. Because without understanding the charging and energy conservation issues, it is very unlikely to live off 350-400W (per family) without a generator. Possible, but unlikely. If it was 900W 15 years ago, now it is ~750W, because panels are aging. Since they anyway run a generator few times a week, the efficiency of their solar system is not critical. Will run generator more often, and buy more fuel, alright...

[Edited on 3-21-2014 by Alm]

baja43 - 3-21-2014 at 11:03 AM

Thanks to all for your knowledge, thoughts and concerns about my situation.
A few responses to keep the ball rolling...
System was well-monitored/maintained for first five years (by original installer); not so much last four (he left). I recently retired, therefore, monitoring/maintenance will be better.
I will replace deteriorating cables and connections and keep a clean environment for batteries.
Interval between visits is 30 days max; batteries are never disconnected from solar.
Room housing controller and inverter has a January minimum temp of 55 and August max of 75.
My "partner" family comes down six times a year for five days of surf fishing and beer drinking...no hair driers, TV, nada.
We are very energy conscious and conservative...small house, no computer, minimal TV watching, etc.
We have gen sets, as needed.
Kudos to you guys and your knowledge, but I'm still a "don't fix what ain't broken" and "don't reinvent the wheel" kind of guy....so,
Why should I change to 12v?
And, how do you"top charge" new batteries?

IF it was a new/substantial house and a new system and a comfortable budget and a long time horizon...then I would do the same due diligence as I do to house and auto purchases on this side, but that's not the case here.

Thanks,
Craig

willardguy - 3-21-2014 at 11:18 AM

screw the 12 volt idea, 6 volt batteries are better suited for frequent charging/discharging cycles. (thicker heavier plates=longer life)

DavidE - 3-21-2014 at 11:41 AM

There is a LOT of competition in the BCI GC 220 battery (golf car). Far less so with "Scrubber Type" 12-volt batteries. More value for the dollar. I use a TDS meter and found typical "purified" water from commercial R/O system have anywhere from 70 to 140 PPM total dissolved solids. The more a battery gets watered with this level of solids the more it gets contaminated. Bring steam distilled water from home.

Alm - 3-21-2014 at 01:42 PM

Quote:

Interval between visits is 30 days max; batteries are never disconnected from solar.
Room housing controller and inverter has a January minimum temp of 55 and August max of 75.
...
Kudos to you guys and your knowledge, but I'm still a "don't fix what ain't broken" and "don't reinvent the wheel" kind of guy....so,
Why should I change to 12v?
And, how do you"top charge" new batteries?

No need to switch to AGM if interval between visits is 30 days, and batteries remain on solar. But do check the water level as soon as you come there.

Controller temperature can be different from the batteries unless the batts are in the same room. Even then, if there is no on-board temp compensation in the controller, it "assumes" that the temperature is 77 and regulates the voltage accordingly. In real life there can be as low as 30 outside in the morning, but controller doesn't know this and therefore doesn't adjust the voltage. So the voltage is always "wrong", and this affects the charging. I don't your controller model, whether it has on-board temp-comp or not.

There is not much need to switch from 6V batts to 12V batts, if I understood the question correctly.

To top-charge new batts, or any batts that are close to full but not 100% full, you put them on Float without loads for a day.

baja43 - 3-21-2014 at 03:22 PM

I light off the propane appliances, check the levels and add distilled water as needed and THEN have a beer, when I arrive.
The controller is a Solar Boost 6024 H from RV Power Products. Batteries live in their own house, with a temp range closer to 77 than 30.
I'm pretty sure I'm going to stick with 6 volt golf cart batteries, which will probably outlive my stay in Colonet.
So, I buy them; bring them to Colonet; install them; switch to float for 24 hours with no load and they are good to go??? No individual charging with battery chargers prior to installation?

Thanks for your patience.
c

willardguy - 3-21-2014 at 03:53 PM

I light off the propane appliances, check the levels and add distilled water as needed and THEN have a beer, when I arrive.

there's your problem, your priority's are all screwed up! :lol:

just clean the cable's up,install the new batteries, done deal.

Bob and Susan - 3-21-2014 at 03:53 PM

Quote:

Originally posted by larryC
Bob,
I'm impressed, the last I remember you hated AGM batteries

everything changes...100 days a year...not a BIG system

and

today I watered the batteries...6 gallons WOW

6v or 12v
if he has a 24v system and loses one battery he loses 4
with 12v he loses two

all batteries fail...not is...its when

only the "old guys" still think the 6v system is better

again...everything changes

larryC - 3-21-2014 at 04:08 PM

Quote:

Originally posted by baja43
Two families, with separate houses, share a long-existing solar system. Both families are vacationers. System has been running successfully for 15 years. Don't want to fix what ain't broken, but the batteries are really old and are dying off.
There are 11 separate panels, measuring 17' wide by 4' high, in total. I have no clue on the watts, as they are all different.
There is a Trace 2.5KW inverter.
There is an RV Power Products/Solar Boost charge controller (12/24 VDC 60 amp output); 36/48 VDC input..I have no idea what that means)
There are eight pairs of 6 volt batteries (Stowaway/Exide GC2) installed in Nov. '05
Can I just buy 16 of the Costco GC2 size golf cart batteries as replacement (about $100 each, out the door) and be done with it?
We are in the Colonet area; small, not fancy homes; our neighbors visit for a total of 30 days per year; we're there about 100 days per year.

The man stated he has 8 pairs of 6v batteries installed in 11/05, that's over 8 years out of the FLA batteries, I'd say they are doing something right. Replace the batteries and keep doing what you are doing cause it is working. Normally I wouldn't recommend 8 parallel strings but it is hard to argue with success.
Larry

DavidE - 3-21-2014 at 04:19 PM

Oh gosh I gotta get offline and start calling all the golf courses. Their 3-cell batteries are obsolete and inferior. Anyone got a ----load of quarters?

baja43 - 3-21-2014 at 04:57 PM

OK, so I lied about the beer...we pop the first one as soon as the rubber hits the dirt off Mex 1, just don't tell anybody.

And, Larry...I'll be fishing BOLA the 7th, 8th and 9th...I'm the guy with the white hair...I'll buy you one of Victoria's margaritas.
c

larryC - 3-21-2014 at 06:01 PM

Sounds like a date, I'll be the old guy with almost no white hair. Wear a rose so I know its you. :light:

Alm - 3-21-2014 at 06:27 PM

Quote:

Originally posted by larryC...over 8 years out of the FLA batteries, I'd say they are doing something right.

Low number of cycles per year probably. Battery life is X cycles, not Y years.

[Edited on 3-22-2014 by Alm]

Alm - 3-21-2014 at 06:51 PM

Quote:

Originally posted by baja43
So, I buy them; bring them to Colonet; install them; switch to float for 24 hours with no load and they are good to go??? No individual charging with battery chargers prior to installation?

Float IS one of charging modes. It's a charging at low voltage ~13.6V per pair, when batteries are full but still require a little current because they always require it due to self-discharge.

They are supposed to be full or almost full from the store. Check the voltage - it should be close to 6.3 - and hook them up to solar. If they are good, the controller will go into Absorb after a few minutes, and then into Float. Let them float for a day, and then use them as you normally do. I assume This is your controller. If so, it's a decent 3-stage charger, though there is no temp compensation if you don't buy their optional sensor. Without sensor it will assume that batts are always at 77F, and when they are not, it will provide a wrong voltage.

baja43 - 3-21-2014 at 07:36 PM

Yes, that is the device mounted in our control room. And, yes, I understand (kinda) the difference between float, bulk and equalize....when the system is running well, as it has until recently, the float charge rate is the one in operation.
I'll follow thru after I have made the purchase and installation and let all you guys know the results.

larryC - 3-22-2014 at 08:00 AM

Quote:

Originally posted by Alm

Quote:

Originally posted by larryC...over 8 years out of the FLA batteries, I'd say they are doing something right.

Low number of cycles per year probably. Battery life is X cycles, not Y years.

[Edited on 3-22-2014 by Alm]

Well yes and no, battery life is many times rated in cycles but years is also a telling factor in a batterys condition. I have some 10 year old batteries that have never been used, would you buy them?
Any way you look at it 8+ years on a fla golf cart battery is pretty good service. I have seen many a golf cart battery here in Bahia stone dead after only 2 to 3 years. Maintenance and proper charging are keys to longer battery life. Starting out with a good battery is also a step in the right direction. Usually you get what you pay for, so cheaper is usually not better in the battery world.
Larry
Larry
Larry

willardguy - 3-22-2014 at 09:27 AM

Quote:

Originally posted by larryC

Quote:

Originally posted by Alm

Quote:

Originally posted by larryC...over 8 years out of the FLA batteries, I'd say they are doing something right.

Low number of cycles per year probably. Battery life is X cycles, not Y years.

[Edited on 3-22-2014 by Alm]

absolutely. we've all heard the adage "battery's never die we murder them" no doubt proper maintenance and charging is key but like Larry points out, start with a good quality battery. the more impurities in the negitive plates, the quicker death will come. these impurities are the reason batteries self discharge. davids point about the quality of distilled water might be valid but the key is the integrity of the lead used. buy quality batteries :yes: