24 to 48 volt upgrade

openplanet · April 2017

I've had four Rolls S530 6 volt batteries in series for about 2.5 years, and am planning to upgrade to a 48 volt system. Some seem to think I can add four new S530s to the string without impacting their health or lifespan, while others think it's a mistake, meaning I'd need to purchase (gulp) eight new batteries. Thoughts? Thanks.

WaterWheel · April 2017

From what I've read and learned by adding to my battery bank is that if the original batteries are less than 12-18 months and in great condition adding more batteries is basically ok but if your current batteries are more than 18 months or have been abused it's not a good financial choice to add new batteries to them.

Your new batteries will degrade to match the old set within 4-6 months. If the old set is barely degraded then not so bad but if the old batteries have been heavily used then you're paying for new batteries that will only last as long as your old batteries.

mcgivor · April 2017

openplanet said:

I've had four Rolls S530 6 volt batteries in series for about 2.5 years, and am planning to upgrade to a 48 volt system. Some seem to think I can add four new S530s to the string without impacting their health or lifespan, while others think it's a mistake, meaning I'd need to purchase (gulp) eight new batteries. Thoughts? Thanks.

My suggestion would be not to add new with used, for reasons pointed out by @WaterWheel ,keep the existing 24V system to operate a load such as a refrigerator, build a 48v system to serve the ballance of loads, or vice versa , perhaps smaller batteries could be used for that, but as I've no knowledge of what the loads are.........just some thoughts

Photowhit · April 2017

Since you'll have to replace your inverter, might consider adding some solar capacity now and angling some of the array South east or south west, to spread your charging profile and perhaps taking some of the pressure off your batteries. Conserve as best you can and save your money for the inevitable large future battery purchase.

For what it's worth, I'm doing this very same thing... May it be a long wait and perhaps a good learning experience shifting loads as best we can to run off the array.

Estragon · April 2017

I'm inclined to agree with the above - adding new batteries to a 2.5yr old bank may not be wise. That said, there are variables to consider.

- Number and depth of cycles on existing. A deeply discharged daily year-round bank may be well into middle age. A lightly cycled bank in a weekend cabin may still be fine.

- It follows that you're going to 48v because loads have grown. If you have tons of pv and run only when sunny but would like capacity to run without sun, and/or use a generator to run and want to use less, that's different than if the bank has been used heavily for the growing loads.

Before making a decision, I would check SGs on all cells, EQ fully to get all cells up to spec as needed, then do a carefully measured load test.

If the EQing finds weak cells, or the load test finds much capacity reduction, I would bite the bullet and buy 8 new. At least then I could have the 4 old ones in reserve (and charged regularly). I would use that along with the gear made redundant by the voltage upgrade for backup to new 48v system if an inverter etc failed. When the 48v bank starts to fail, odds are some batteries will go before others, at which point you may be able to use some of the stronger "old" batteries to keep the bank going for a while.

If I did add 4 to the existing bank, I would swap out the old for the new and keep running 24v for at least 60 cycles or so on the new to get the new bank broken in, and do SG check and EQ on old and new battery strings individually before putting them into use as a single string. I would also want to be sure I had lots of charging capacity for the combined string as mixed life batteries + undercharging will likely end badly.

jonr · April 2017

If you do add batteries to an existing string in series, I'd install a balancer (eg, HA-02) to help with fixing the inherent imbalance. In parallel, I wouldn't be so concerned. The new batteries will work harder and age faster until they match the older ones.

openplanet · April 2017

Thank you all for the very informative comments. As a few of you suggested, I probably will bite the proverbial bullet and upgrade to 48vdc via 8 (gulp) new batteries and a new (gulp) 48 volt inverter/charger. BTW, any thoughts or observation on AimsPower? Thanks again all.

Raj174 · April 2017

The Aims inverters I have seen have a very high self consumption rate. I'd choose one the top 3 quality inverters, Outback Power, Schneider Electric or Magnum.

Estragon · April 2017

I'm happy with my Outbacks, but if I was inverter-controller shopping I'd seriously consider the new Midnite b17. No idea what pricing will be (won't be cheap), but sure looks nice.

nickdearing88 · April 2017

Me too, can't wait for the B17 release and prices.

Horsefly · April 2017

I know I must be in the minority here, but... I really wish that MidNite didn't go for the cheesy aesthetic look on all their stuff. Outback is hardly better. As a relative newcomer, I started looking at Magnum, Outback, MidNite, and Schneider. Almost right away I saw the Outback and MidNite equipment at targeted towards frustrated nerds instead of real systems. As a former frustrated nerd (

), I was a bit put off by the appearance. I'm sure there are loads of fans that like the cool look of this stuff, but for people who are mainly looking at how to power their home, is this really the way to go? As far as I can tell, both Outback and MidNite make great products. Unfortunately the toy-like look turned me off in some of the final comparisons.

When I looked at the B-17 video, I was really impressed by the technology that was apparently behind it all. By aiming the front-facing stuff at nerdy and WWII buffs, I think they missed the point. Maybe it's just me.....

mcgivor · April 2017

Horsefly said:

I know I must be in the minority here, but... I really wish that MidNite didn't go for the cheesy aesthetic look on all their stuff. Outback is hardly better. As a relative newcomer, I started looking at Magnum, Outback, MidNite, and Schneider. Almost right away I saw the Outback and MidNite equipment at targeted towards frustrated nerds instead of real systems. As a former frustrated nerd ( ), I was a bit put off by the appearance. I'm sure there are loads of fans that like the cool look of this stuff, but for people who are mainly looking at how to power their home, is this really the way to go? As far as I can tell, both Outback and MidNite make great products. Unfortunately the toy-like look turned me off in some of the final comparisons.

When I looked at the B-17 video, I was really impressed by the technology that was apparently behind it all. By aiming the front-facing stuff at nerdy and WWII buffs, I think they missed the point. Maybe it's just me.....

You're not alone, they should make two versions, one with the goofy art deco look and another with a serious industrial business like appearance, to appeal to both markets, by no means would I consider their quality inferior, in fact they are superior in many respects, it's just the looks. The names are also of putting, Kid, Brat and Wizz Bang Jr., I'm sure they would appeal to more people if they were something like K 30, or WBJ 1, ......just opinions, some may actually like the look, names and so forth but personally they don't do much to attract my attention.

Estragon · April 2017

The art deco thing is admittedly a marketing gimmick and may not appeal to everyone.

Sometimes marketing gimmicks work out, like the computer company named after a fruit that made some real dud products and nearly went under, then made an mp3 player and later phones which featured design as the main differentiator.

jonr · April 2017

Gateway 2000 had cows and lost to the more businesslike Dell.

Estragon · April 2017

Maybe if they had started making phones with cow spots they would still be around?

westbranch · April 2017

don't forget the 'Gudgel link' between Outback and MidNite..... ie the 2 brothers that basically stated their careers at Trace, moved on to Outback, sold out and started MidNite... ps AFAIK each of the names, like the KID, have a significant tie to someone (Mario) or something, like the WB jr (Whiz Bang jr) ???must have worked right off the get go?, that has happened in the factory.... another is, have you ever noticed the close similarity of the MX60 and the Classics? the looks don't bother me nor get me going, it's 'just' a piece of GOOD equipment with some quirky design elements... chest pounding over.

Photowhit · April 2017

Estragon said:

The art deco thing is admittedly a marketing gimmick and may not appeal to everyone.

Sometimes marketing gimmicks work out, like the computer company named after a fruit that made some real dud products and nearly went under, then made an mp3 player and later phones which featured design as the main differentiator.

I find this very interesting. To the point that Apple made great 'ready to use' product in computers and 'nerds' hated them! Where they found a market is in graphics, because they did the job so much better end to end. And in education again simply worked.

They were always a creative company, did lots of interesting design work, but the Mp3 player was truly a 'Creative' design! How creative? It wasn't really their design, but a design by a company by the name Creative. What they did so well was promote and sell the 'cool factor'.

https://www.cnet.com/news/apple-settles-with-creative-for-100-million-1/

I think the brothers Gudgel want to be on the cutting edge, and do some one time cast case design. Similar to what Apple did, but they, also were on the cutting edge of the electronics design.

westbranch · April 2017

have a College/University Dr. friend... He LOVED his Apples and MAC's..(pardon the fruit pun). he struggled for years to keep using them until time came to doing the data processing for his thesis...
He finally admitted defeat and Microslopped it as those neat graphics machines can not handle heavy data crunching... I'm still not an Android fan yet, may be a long time too...

Photowhit · April 2017

Actually, I would suspect a specific program that he couldn't run with Apples. Graphics are all numbers and calculations, I've largely been out of the Graphics world for 10 years, but suspect Apples are still very good, I do have a friend who has a DNA analysis lab, Her sequencer ran on an older Mac for years.

Oddly enough my brother was one of those who never thought much of Apples/Mac's, He worked for IBM while getting his EE and went on to get a Masters in AI from Michigan, His family is down to 1 Windoz machine (out of many) and after years or being a software engineer, he writes I-Phone Apps!

http://www.zcage.com/

I use to be a Photoshop professional, He shared a seminar he went to where part of the presentation was a demonstration of electronic architecture, back when the apples 'pipe' was quite a bit higher than Windoz. They come in and talk about comparing speed in processing an image, they have a top end Mac and Windoz and start a process on the Windows machine, and the start the mac up and load the image and start the same process on the 'slower' Mac machine and of course it finishes just ahead of the windows machine. Of course Photoshop was written for Mac's originally, so there might be an advantage in the translation, this was a while back, I think in the days of PS 5.5.

westbranch · April 2017

You are right on that speed issue... this is the thing that WDoz does faster, don't know about Linux, heavy data (number) crunching especially when you have multiple data bases that are measured in Mega bytes... and compared to my last project, before throwing in the towel, his was simplistic. Took us ~ 3 years to build and proof the data ( all map based, multi layers) kinda liked that part!
PS 5.5 yup still got the CD..

24 to 48 volt upgrade

Comments