navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address. Following continuous spam/hack attempts on the forum, "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1] 2   Go Down
  Print  
Author Topic: Rolls batteries rock  (Read 6562 times)
camillitech
Hero Member
*****
Offline Offline

Posts: 5430



WWW
« on: July 03, 2013, 05:57:38 AM »

Having fitted a set of these http://www.navitron.org.uk/product_detail.php?proID=798&catID=157 to my mates 'off grid' system over a year ago http://lifeattheendoftheroad.wordpress.com/2012/04/16/bouncing-batteries/  I am seriously impressed with their performance. Looking after around half a dozen or more FLA banks over the last ten years and having taken and logged thousands of SG readings I'm simply staggered by these batteries

 

Even after a years use the readings are consistently higher than any cell I've ever recorded and regularly 'off the scale' as they were on Sunday.



Out of the twenty four cells some twenty were at 1.3 with four being around the 1.28 mark, though a two hour EQ sorted that out.
http://lifeattheendoftheroad.wordpress.com/2013/07/01/i-wish-id-taken-a-picture/

 Now I know that hydrometers are not the most accurate of instruments but I've had this 40 Durite one for years now and it's what I use on all the banks apart from the ones at work.

I am seriously thinking of installing a set at the new house instead of 'fork lifts', as far as I can see their size and shape makes them easier to transport, fewer connections and less prone to stratification . Disadvantages being they are harder on the back to top up and have a larger footprint. Also, I guess that one dud cell would mean changing three but I've never had much success with changing single cells anyway, the others usually fail very shortly afterwards.

Sure there are, on paper better performing cells for the money, but this is real life observation of a working bank over fourteen months of a five year warranty.

Cheers, Paul
« Last Edit: July 03, 2013, 05:59:55 AM by camillitech » Logged

http://lifeattheendoftheroad.wordpress.com/

'Off grid' since 1985,  Proven 2.5kW, Proven 6kW direct heating, SMA SI6.OH, 800ah Rolls, 8kW PV ,4xTS45, Lister HR2 12kW, , Powerspout pelton, Stream Engine turgo, 60 x Navitron toobs and a 1500lt store. Outback VFX3048 and 950ah forklifts for backup,
Justme
Hero Member
*****
Offline Offline

Posts: 3560


« Reply #1 on: July 03, 2013, 06:23:48 AM »

Could the high SG readings be due to a stronger initial fill strength of acid?

That could be intentional due to the internal chemistry or an accident.
Logged

Navitron solar thermal system
30 x 58mm panel 259L TS
1200watts solar 120vdc
FX80 Solar controller
2 x Victron Multiplus II 48/5000/70
Cerbo GX & GX 50 touch
BMV 700
6kva genny
48v 1000ah
Grid Possibly coming soon
camillitech
Hero Member
*****
Offline Offline

Posts: 5430



WWW
« Reply #2 on: July 03, 2013, 07:47:28 AM »

Could the high SG readings be due to a stronger initial fill strength of acid?

That could be intentional due to the internal chemistry or an accident.

Perhaps Justme, but I have seen them lower occasionally (but never in the white section) and they always seem to return to the higher readings. The bank does have hydro input but quite often that will be turned off at this time of year so it relies on 1.2kw of PV.
Logged

http://lifeattheendoftheroad.wordpress.com/

'Off grid' since 1985,  Proven 2.5kW, Proven 6kW direct heating, SMA SI6.OH, 800ah Rolls, 8kW PV ,4xTS45, Lister HR2 12kW, , Powerspout pelton, Stream Engine turgo, 60 x Navitron toobs and a 1500lt store. Outback VFX3048 and 950ah forklifts for backup,
bar
Full Member
***
Offline Offline

Posts: 198



« Reply #3 on: July 03, 2013, 06:44:01 PM »

Hi Paul

I have had rolls batteries in for 5 years now with no noticeable age-related drop in performance. Although i never felt i have got "design" performance; that maybe down to the cabling. They always score well and even on testing. i do notice some variation in temp between the cells on equalisation charging - must be resistance related?

they do take some topping up, even with the hydrocaps. last check they all took a litre each to bring up to level (plates were not exposed).

i am considering the merits of re-filling with new acid when they eventually start to fall off. any thoughts on the benefits of this?

i am not looking forward to the day i will need change them because they weigh 1.5 cwt each (4 volt) and dent the account. Undecided

cheers

Bar
Logged

we don't plan to fail we only fail to plan
camillitech
Hero Member
*****
Offline Offline

Posts: 5430



WWW
« Reply #4 on: July 03, 2013, 09:22:34 PM »

Hi Bar,

never thought to check temperature difference on charging, seems like another job for the IR thermometer  Cool Often wondered about rejuvenating with acid. I did try it without success in the 70s though, when batteries used to come 'dry charged' and had to be filled with acid prior to use. There was always drums of sulphuric acid about the stores but it never seemed to restore life to a dud battery, however I was only young and don't remember flushing out the old stuff very well. Considering how difficult it is to legally get rid of the stuff I'd be inclined to give it a miss. I once emptied a battery onto the grass behind the house and it's still brown and lifeless five years on  Cry

Good luck, Paul
Logged

http://lifeattheendoftheroad.wordpress.com/

'Off grid' since 1985,  Proven 2.5kW, Proven 6kW direct heating, SMA SI6.OH, 800ah Rolls, 8kW PV ,4xTS45, Lister HR2 12kW, , Powerspout pelton, Stream Engine turgo, 60 x Navitron toobs and a 1500lt store. Outback VFX3048 and 950ah forklifts for backup,
skyewright
Hero Member
*****
Offline Offline

Posts: 1769


« Reply #5 on: July 04, 2013, 02:26:43 PM »

Having fitted a set of these http://www.navitron.org.uk/product_detail.php?proID=798&catID=157 to my mates 'off grid' system over a year ago http://lifeattheendoftheroad.wordpress.com/2012/04/16/bouncing-batteries/  I am seriously impressed with their performance. Looking after around half a dozen or more FLA banks over the last ten years and having taken and logged thousands of SG readings I'm simply staggered by these batteries
So if I have it correctly each battery is rated at 400Ah @ C20 and there's 8 of them linked as 2 lots of 4 to suit the 24V input the inverter expects?

I'm sure I ought to know how to work it out, but what's that provides as usable kWh from "full" to "better stop now"(50% DOD?)  - assuming sun doesn't come out along the way?

Logged

Regards
David
3.91kWp PV  (17 x Moser Baer 230 and Aurora PVI-3.6-OUTD-S-UK), slope 40, WSW, Lat 57 9' (Isle of Skye)
Eleanor
Hero Member
*****
Offline Offline

Posts: 2574



« Reply #6 on: July 04, 2013, 03:38:04 PM »

The acid concentration in a battery decreases over time as sulphate ions irreversibly (under normal charging conditions) end up on the plates. Just emptying out the acid and replacing it with acid of the original concentration will increase the rate of discharge as there will be more ions available to form lead sulphate on both plates.

I think Rogeriko has changed the acid in batteries. From memory the cells have to be charged as much as possible ie get as much sulphate off the plates as you can. The acid is then tipped out (not forgetting that the plates are charged!) and replaced with water and charging continued to try and remove more sulphate.

Having ruined numerous frocks working with similar and higher concentrations of nitric acid (without the excitement of it being part of a battery) it's not something I'd be contemplating unless I really knew what I was doing  signofcross

Logged

I'm doing this for free, please be nice to me surrender
"Very few batteries die a natural death ... most are murdered" stir
billt
Hero Member
*****
Offline Offline

Posts: 833


« Reply #7 on: July 04, 2013, 04:03:20 PM »

Energy is Ah x Volts.
In this case theoretical total capacity is 400 x 24 = 9600 Whr.
Divide by 1000 to get 9.6 kWhr.
Divide by 2 to get capacity to 50% DOD = 4.8kWhr.
Logged
djh
Hero Member
*****
Offline Offline

Posts: 2128


« Reply #8 on: July 04, 2013, 04:15:49 PM »

I once emptied a battery onto the grass behind the house and it's still brown and lifeless five years on  Cry

Put some lime on it or mix some into the soil?
Logged

Cheers, Dave
rogeriko
Hero Member
*****
Offline Offline

Posts: 1435



WWW
« Reply #9 on: July 04, 2013, 05:11:49 PM »

Indeed Eleanor my clothes have more holes from messing around with battery acid than a swiss cheese. I just successfully restored 24 1000Ah OPzS batteries that had shorted plates because of too much lead paste that had fallen to the bottom. (DO NOT TRY THIS AT HOME).  I emptied out the acid then drilled 5 holes in the side at the base, I washed out all the gunk with a hosepipe through the holes and from the top down. When the bottom was clean I sanded and filled the holes with 2 part epoxy and put the old acid back in. I charged them for about a week at 30A, they were bubbling like crazy, and then added concentrated sulphuric acid, no more than 100 grams at a time so the acid doesn't get hot, until the hygrometer showed full charge. After sitting for 2 days I connected 12 of them to my inverter (24v) and they ran the house for 2 days and 3 nights without being charged at all from solar or wind, about 24kwh. I have just recharged them and they went back to full just like a new battery. 


* batteryfixsml.jpg (112.97 KB, 1280x960 - viewed 491 times.)
Logged

biff
Global Moderator
Hero Member
*****
Offline Offline

Posts: 12060


An unpaid Navitron volunteer who lives off-grid.


« Reply #10 on: July 04, 2013, 05:32:11 PM »

Wow!, Roger,
               Now there is news.So it can be done if you know what to do!Exellent news.
         Just one thing though,When you are hosing out the cells with water,Is it ordinary water,?
                                                                        Biff
Logged

An unpaid Navitron volunteer,who has been living off-grid,powered by wind and solar,each year better than the last one.
rogeriko
Hero Member
*****
Offline Offline

Posts: 1435



WWW
« Reply #11 on: July 04, 2013, 06:29:04 PM »

I am using ordinary well water from granite rock so it has little dissolved salts. Rain water would be better you don't need much because the lead waste drops to the bottom of whatever container you are using to catch the waste almost immeadiately.
Logged

skyewright
Hero Member
*****
Offline Offline

Posts: 1769


« Reply #12 on: July 04, 2013, 06:33:50 PM »

Energy is Ah x Volts.
In this case theoretical total capacity is 400 x 24 = 9600 Whr.
Divide by 1000 to get 9.6 kWhr.
Divide by 2 to get capacity to 50% DOD = 4.8kWhr.
Thank you.
Logged

Regards
David
3.91kWp PV  (17 x Moser Baer 230 and Aurora PVI-3.6-OUTD-S-UK), slope 40, WSW, Lat 57 9' (Isle of Skye)
biff
Global Moderator
Hero Member
*****
Offline Offline

Posts: 12060


An unpaid Navitron volunteer who lives off-grid.


« Reply #13 on: July 04, 2013, 07:33:02 PM »

Cheers Roger,
               Thanks for that info.
                                  Biff
Logged

An unpaid Navitron volunteer,who has been living off-grid,powered by wind and solar,each year better than the last one.
camillitech
Hero Member
*****
Offline Offline

Posts: 5430



WWW
« Reply #14 on: July 04, 2013, 07:45:15 PM »

Energy is Ah x Volts.
In this case theoretical total capacity is 400 x 24 = 9600 Whr.
Divide by 1000 to get 9.6 kWhr.
Divide by 2 to get capacity to 50% DOD = 4.8kWhr.

Not quite Bill,

they're 6v 400ah each and there's eight, two parallel banks of four, 19.2 and 9.6kWh.

Cheers, Paul
Logged

http://lifeattheendoftheroad.wordpress.com/

'Off grid' since 1985,  Proven 2.5kW, Proven 6kW direct heating, SMA SI6.OH, 800ah Rolls, 8kW PV ,4xTS45, Lister HR2 12kW, , Powerspout pelton, Stream Engine turgo, 60 x Navitron toobs and a 1500lt store. Outback VFX3048 and 950ah forklifts for backup,
Pages: [1] 2   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!