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]   Go Down
  Print  
Author Topic: Lifetime of batteries when left disconnected in a cold garage?  (Read 3376 times)
dan_aka_jack
Hero Member
*****
Offline Offline

Posts: 703



WWW
« on: February 22, 2008, 10:00:05 AM »

How much damage would be caused to lead-acid batteries if left for several years in a cold (but dry) garage, unconnected and unmaintained?

I've been casually watching batteries (especially large collections of UPS batteries) on eBay for a while and every now and then a fantastic deal comes along.  The problem is that I don't have anywhere to keep 1 metric tonne of batteries in my current house so I was thinking that I could stick the batteries in my parent's spacious garage until I need them (which might be several years).  Would I ruin the batteries by leaving them unattended in a cold garage?

Many thanks, Jack.
Logged

Paulh_Boats
Hero Member
*****
Offline Offline

Posts: 2827



WWW
« Reply #1 on: February 22, 2008, 01:01:22 PM »

They usually need to be charged every few months as they slowly self-discharge. If they discharge down to a low voltage they can get damaged and their life is shortened. The self-discharge rate and the robustness varies with different types of battery.

If you wired them up in parallel, a simple solar panel and 12V controller might keep them topped up and healthy. Alternatively a plug in timer that charges them for an hour a week would be economical - you would have to experiment with the timing  to make sure they are above 12.00 Volts at all times.

-Paul
Logged

30 tube thermal,
2.3kW PV see:
http://www.solarmanpv.com/portal/Terminal/TerminalMain.aspx?come=Public&pid=17067

LED lighting in every room
NO tumble dryer, +370 kWh per year
RichardKB
Sr. Member
****
Offline Offline

Posts: 450


« Reply #2 on: February 22, 2008, 04:44:15 PM »

They don't last that long if left without any charging, also a flat battery will freeze.

Rich
Logged
Gary T
Jr. Member
**
Offline Offline

Posts: 89


« Reply #3 on: February 22, 2008, 09:48:14 PM »

I think the only way to keep them without a charge would be to keep them in a dry condition, i.e. drained of electrolyte, however, this would result in having to store several hundred litres of sulphuric acid contaminated with lead. I think it would be far better to wait until the batteries are needed. What's more, other types of battery as well as ultra-capacitors may well be developed / come into common use in the next few years, so allowing a number of different options to be considered.
Logged
Bob
Sr. Member
****
Offline Offline

Posts: 430


WWW
« Reply #4 on: February 23, 2008, 06:12:03 AM »

My main set was left by it's previous owner in an unheated shed on an Irish mountain for nearly two years without a charge.  It has taken me 5 years to get them back to a half decent condition. 

I would recommend a plug in timer (7 day variety) and a suitable charger.  Set up a weekly charging cycle.
Logged

It's not what you make, it's what you use that counts!
dan_aka_jack
Hero Member
*****
Offline Offline

Posts: 703



WWW
« Reply #5 on: February 23, 2008, 10:45:11 AM »

Great stuff, thanks loads for all the replies.

Jack
Logged

dan_aka_jack
Hero Member
*****
Offline Offline

Posts: 703



WWW
« Reply #6 on: February 23, 2008, 10:50:54 AM »

On a related point:

What's the average life-time of lead-acid batteries if you look after them?  And are there any good "battery husbandry" guides online?!?
Logged

martin
Hero Member
*****
Offline Offline

Posts: 15733



WWW
« Reply #7 on: February 23, 2008, 11:31:56 AM »

some of the "better" battery distributors give some guideline figures - they refer to "DOD" (depth of discharge), and number of cycles - typical figures would be..........
el cheapo leisure battery - 100 cycles to 50% DOD - which means run them down to half capacity, they'll be knackered after 100 times................. the figures are fairly "pro rata", so if you only used 10% DOD, they'd last 5 times as long...........500 cycles Cool
AGM battery - (advanced glass mat) - 300 cycles to 70% DOD (2,100 cycles to 10% DOD)
Top of the range Gel Battery - 400 cycles to 80% DOD
-which means that if you only discharged 10% per day you should get around 7-8 years out of them~!
(these are similar to "golf cart batteries" which are regularly deeply discharged, with this sort of use, they'll do 1-2 seasons.......) Cool
I think the above figures bring into focus the necessity for careful design of battery systems, and choice of batteries (and why it makes a lot of economic sense to only discharge small amounts relative to capacity...) Cool
The 10% "rule of thumb" is fairly accurate - design to never take more than 10% of the battery's capacity per day, never ask a battery to discharge at more than 10% of it's amperage capacity (110 amp battery - maximum current draw 11 amps), and never charge at more than 10% of it's amperage capacity (110 amp/hr battery  - 11 amps) angel
« Last Edit: February 23, 2008, 12:01:20 PM by martin » Logged

Unpaid volunteer administrator and moderator (not employed by Navitron) - Views expressed are my own - curmudgeonly babyboomer! - http://www.farmco.co.uk
Gary T
Jr. Member
**
Offline Offline

Posts: 89


« Reply #8 on: February 23, 2008, 06:51:32 PM »

One more point, keep the battery store as cool as possible, e.g. outside against a North facing wall and with good ventilation. Temperature is a significant factor in battery life, hence the short life of UPS lead acid batteries (around 3 years in use) in spite of keeping them in a fully charged state!
Logged
Bob
Sr. Member
****
Offline Offline

Posts: 430


WWW
« Reply #9 on: February 24, 2008, 06:41:46 AM »

Picking up on Martin's comment about top of the range gel batteries only giving 7-8 years.  Having never used gel cells I could not comment but that seems a really bad figure in comparison to purpose built standby power cells.  Have a look at the cells on the bottom of this page http://www.abpowersystems.ie/prod01.htm  My main set originally came from them and are still going strong after use, abuse and 16 years.


* battery1.jpg (61.91 KB, 563x381 - viewed 364 times.)
Logged

It's not what you make, it's what you use that counts!
Pages: [1]   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!