Let's Talk Battery Banks

[crazyidea]

Smitty, wish I could help as I have researched this topic extensively in the past, but as you said things tend to slip the mind when we are not actively engaged with certain subjects. I plan to do the off grid idea, but I never did figure out how long I would have to go before I saved money...I just liked the idea of sticking it to the man by not being burdened with his power bills even if the upfront costs me out the you know what.

[paul iossi]

since you are looking at industrial batteries with the 8D's why not go the next step and look into the ultimate deep cycle battery and check out electric forklift batteries, they are not AGM's but they could be mounted outside with a roller or lift system for servicing once a month. the other plus is that they are rebuildable one cell at a time if the need occurs.

[crazyidea]

I considered the forklift batteries also, but(correct me if I'm wrong) don't you have to both vent those and keep them within certain temperature specifications. I mean with a non-venting battery you can store it inside without worrying about gassing yourself.

[paul iossi]

smitty; i haven't been around around industrial batteries for 15 years or better, i don't know if they are available as AGMs or not, but when i was still active in that buisiness group 31 batteries were the largest AGMs available, it's amazing how fast things change when you're looking elsewhere.

[John]

I'm in the same boat with the did a bunch of research, but that was a while ago.

I used to rely on a couple of local shops to see what they install in solar situations. The used to love the Trojan T-105's but now they seem to favor the Interstate UL-16's. So lately, I've been considering the L16, but been looking at DEKA. These are all lead-acid types, around 300-cycles and 3 year pro-rated (2 year replacement, then pro-rated after that) warranty. Generally about $1 per Amp-hour. Then I saw Rolls Battery company. I don't know anything about them other than they offer larger batteries generally around $0.90 per Amp-hour, but offer a 10-year (3 year replacement, then pro-rated) after that. So many choices...

As for temperature, I had read that (please correct me if I'm wrong) a battery's capacity is reduced in the cold, meaning it doesn't store as much energy and energy comes out and goes in more slowly. But also, it's lifespan increases in cold weather. I was dead-set on storing my batteries in-side, but lately have been researching under-body truck bays and draw slides. I'm with smitty about putting the batteries on a drawer and slide them in and out to do basic maintenance, you may need to add a little length to your a DC cable to have it bend and flex, but not too bad. I'll put them in a weather protected, but vented underbody box rather than inside, but still with smitty on an outside access door. If you do go the unsealed lead-acid type, maintenance is key, the more you monitor and take care of your batteries, the longer they will last. And it seems like its quite a monetary investment.

As for the 1-12V vs 2-6V, I don't think there's any real difference to worry about. Like you said, there may be a little more weight to the battery case and also a couple of extra wire connections, but as long as they are greased and bolted should be fine. Both the T-105's and UL-16's I mentioned above (the local solar guys love and swear by them) are 6-Volt batteries.

[John]

Originally Posted by Smitty

John, if you haven't already bought batterys, and don't have a local source, heres an option that offers free shipping:

http://www.tristatebattery.com/product_ ... ts_id=1106

lol, and I just happen to bookmark the page that will load.....with that monster battery

But I wouldn't mind having a handful of 'em

Woah, I may have to rethink things. The UL16H is approximately $380 for 375 aH @ 6VDC. So 700 for 375 aH @ 12VDC. About a 50 cents an amp hour. Your monster battery is $500 for 245 aH, about 50 cents an amp hour. I thought AGM batteries were supposed to be a lot more expensive?

From what i remember a while ago, there was no maintenance for an AGM battery? Would you even need a drawer? or a vent? No off-gassing... Maybe you could even put the inverter / charger / etc.. in the same bay? Perhaps just a big box to put them in, not worry about being able to slide them out at all.

How many cycles is your monster battery rated for?

[paul iossi]

back in the day it was explained to me that any battery only had xx amount of charge/discharge cycles in it's life, with the best lifespan if you kept the battery from being severely discharged but yet not charged to often, so make sure that you use batteries designed for extended-deep cycle use (slow steady charge / discharge rates) VS starting batteries (high amp draw /short cycle time). It appears that the larger the individual cells are the more amp rating they have, so a 6V battery has 2x+ the amp rating of a 12V.
Shop for the most amperage at a given cost, take into account who makes/markets the battery and their corporate history/health, a super deal on batteries from someone that won't be their to help with service and warranty is no deal.
Battery technology continues to change by leaps and bounds, AGMs are lead acid batteries that are built with paste on film and rolled up cell construction instead of lead plates submerged in liquid, continue to follow as small cordless tool battery technology advances, it is what is driving the electric car technology

[paul iossi]

Agreed, 6 vs 12V is a wash cost wise but the larger individual cell size of the 6V might be an advantage, also golfcart sized batteries are a lot easier to manouver than 8D's from both weight and physical size aspect. you might consider making a HD drawer slide using small channels inverted into eachother and plastic blocks cut from a poly cuttung board for sliders, use a piece of ACME threaded rod to jack the drawer open and closed.

[John]

Another option for slides would be to go with something like Slide Master (http://www.truckcargobed.com/slide_master.html) instead of individual slides. But it is more expensive than the slides you showed.

I would like to see someone try the method above:

Originally Posted by paul iossi

you might consider making a HD drawer slide using small channels inverted into eachother and plastic blocks cut from a poly cuttung board for sliders, use a piece of ACME threaded rod to jack the drawer open and closed.

I was looking at my stock ward battery box the other day, it is just two inverted steel pieces. Sure it doesn't slide out the smoothest, but how often are you going to be opening and monitoring your batteries.

[ezbme]

Smitty

I know this isn't as much power as you are lookng for but we have been off the grid now for about 5-6 weeks. The system we set up in the bus has (4) 100AH batteries we got from the local Batteries Plus store. They are Werker brand & they are AGM. We went with AGM mainly for the ability to keep them inside the bus as the solar is being used for our business office & to help control temperature plus we didn't want to have to maintain them. BP gave us the "commercial" rate on the 4 batteries & were gernerous enough to throw in the cables for free! It totaled to $660 before taxes (or $165 each). They told us normal retail if buying one battery is $259.00 so it was a substantial savings. We are totally happy with the system as the weather has turned on us already (snow in forcast tonight) & we have had cloudy days so we are not getting a full charge everyday from the panels...
Just a little info from a newbie to solar!

Jonathan

[ezbme]

Originally Posted by Smitty

I know I'm going "overkill" on my battery bank (well, the entire PV system to be honest). I'd rather do it once, and have surplus reserves, as opposed to adding more to the system later-on, or having to run the gen more than a minimum. I'd like to be self-sustaining & not have to use the gen at all....wishful thinking more than likely .

I can't remember what you have in the way of panels? I'll have to go look.

Smitty

We have 3 90 watt monocrystaline panels, 4 100AH AGM's & a Xantrex Pure Sine Wave inverter. We normally run a laptop, modem, light, stereo or TV, & usually have some battery chargers doin their thing ( I think that is everything). Also I work at night too (since we got a Little Buddy propane heater-gettin cold here) so the panels are on standby alot of the time. We haven't had any issues with loss of power even after 3 overcast or rainy days. Keep in mind tho that we have an average of 6 hours a day of insolation (winter) as New Mexico IS a sunny state...

Jonathan

[John]

Originally Posted by Smitty

The item John listed is fine, but would likely require serious modification and cutting down, probably scrapping the majority of the materials in the unit. No sense in buying more than needed to cut-away 75% of the materials. I didn't see a cost, but it's likely more expensive than the idea I have, plus probably more labor-intensive as opposed to just starting from scratch.

Smitty

FYI, the pricing is in PDF so you may not be able to read it. They will make the platform to any width / height / weight (1000 or 1500 lb ratings) desired. And use no-skin, plywood or steel. No after-market cut-away / scrapping / modifications necessary.

[ezbme]

Just an FYI Smitty, our cabin is set up with 4 Optima yellow top batteries. They have been in use for the summertime 2 summers in a row & now we are using them full time & they work great. Not sure of the AH or cost difference to AGM but in our experience I am satisfied with them!

Jonathan

[ezbme]

Originally Posted by Smitty

Aren't the Yellow-Top Optimas AGMs? I'm gonna spend good money on my batteries, too much will ride on them, and I want plenty of reserve power in the event of "unproductive" solar days......now if I could get this dark cloud to stop following me around

Smitty

Ah Dangit Smitty! Now I am gonna have to break away from work, waaalk back thru the snow to the cabin & look at the battery bank cause now ya got me wonderin... I always thought they were gel cell but now I am not sure. I have been so busy i haven't had the chance to really check out the cabin setup...pathetic huh?

I am going to build a wind generator & if the first one works I will build a second so the bus & cabin are covered. This way I have backup power for each system as when it rains here it is usually windy...got myself covered for the most part then...

Jonathan

[Andreb]

*** paging the_experience ***

[TygerCub]

Originally Posted by Smitty

I'm gonna spend good money on my batteries, too much will ride on them, and I want plenty of reserve power in the event of "unproductive" solar days......now if I could get this dark cloud to stop following me around

Oh Smitty, make that cloud WORK FOR YA! If it's cloudy, then there's probably wind (and not from the double bean chili with deviled eggs of the night before ). Get a windmill to help top off those uber batteries. Or, build one like Jonathan's doing.

Northern Tool selection of windmills:http://tinyurl.com/5ctggk
or
DIY Vertical Axis windmills (more efficient for mounting on top of a bus):http://tinyurl.com/neescn

[John]

Originally Posted by Smitty

John, (you're right, for some reason I can't view PDF's) could you see what the price is for something around 24" deep X 60" long? Or anything close to that.....just for curosity?

Smitty

24" deep x 60" long looks to be $348 for Aluminum 1000lb / 70% extension / no deck (just the slides no plywood or metal deck)
$450 for Aluminum heavy duty 1500lb / 70% extension / no deck
$314 for Steel 1000lb / 70% extension / no deck
$405 for steel 3-rail 1000lb / 100% extension / no deck

Plenty of more options / prices / etc... but this should get a ball-park.

I'd go with the steel 3-rail 1000lb / 100% extension or build your own out of a combination of lesser slides.

[ezbme]

Smitty, Since you mentioned Sean's bus I thought you would be interested in more info from a solar thread I had posted a while back- (sure you read this but thought since you asked it just gives one persons usage & equipment requirement info & it looks like quite a system... thread: viewtopic.php?f=11&t=4516&p=38725#p38725

This is SeanF's usage on his bus:

ezbme wrote:
Sean, What wattage panels are you using? Actually if you don't mind what is your system comprised of - panels, batteries, inverter etc? I am curious as to the approx useage (wh) you are using daily & the sytem you have set up... Thanks!

Jonathan

4 x KC120 panels (120 watts each, tilted to 50 degrees in winter months)
400 watt wind turbine (not currently set up)
4 x Trojan L16H batteries (6 volts, 420 Amp hours each)
MorningStar Tri-Star TS-45 solar charge controller
Square-D fused safety disconnect
Exceltech pure sine wave inverter
Xantrex DC Load controller
Trimetric 2020 system monitor

I use about 80-100 amp-hours per day (960-1200 watt-hours).

Loads:
Desktop PC/flatscreen monitor 9 hrs/day x 5 days/week
Laptop computer about 60 hours per week
Satellite internet modem, router, 60 hours/week
DC fridge, draws 25 watts, runtime depends on bus temp
LED lighting
DVD player, car stereo, 10 hours/week
2 small muffin fans, always on
Various chargers - cell phone, AAA & AA batts, cordless power tool batteries, etc
Occasional coffee grinder, food processor, electric shaver, water hearer exhaust fan, water pump

That's about it.

[ezbme]

Originally Posted by TygerCub

Oh Smitty, make that cloud WORK FOR YA! If it's cloudy, then there's probably wind (and not from the double bean chili with deviled eggs of the night before ). Get a windmill to help top off those uber batteries. Or, build one like Jonathan's doing.

Northern Tool selection of windmills:http://tinyurl.com/5ctggk
or
DIY Vertical Axis windmills (more efficient for mounting on top of a bus):http://tinyurl.com/neescn

Thank you Than you TC for the DIY Verticle Axis windmill...
I AM going to build one of these soon, weather permitting! AND I learned how to cut cirles on the table saw, how cool! Do you have any info for completing the windmill - electronics & stand/pole for it to be complete?

Thanks! Jonathan

[ezbme]

Originally Posted by Smitty

Thanks for the link!

Smitty

No problem! You have helped me out a bunch... I am gonna try to build The verticle windmill. Got me thinkiing how much power I could generate as it is pretty windy on the property!

Jonathan