Agri Vehicles Insurance from Greenlands

Author Topic: which are the best batteries for a battery bank 12v-110ah or 12v-120ah  (Read 8708 times)

lynnandrob

  • Joined Jan 2013
hi
ive been looking at deep cycle batteries and cant work out which would be the best brand and the best ah for the battery bank i want to make in my other post.what batteries do you use and are they any good?
ill only need mine to run a security system,burglar alarm,a few security lights with motion sensors,a couple of lights that will be 11w energy saving bulbs,a pump for the cental heating and maybe a toaster and tv,nothing big like a dryer or washing machine.as mentioned in my other post we are not there all the time just at weekends which gives the batteries plenty of time to recharge.any pictures of your set up would be great

rob

smiley bucket

  • Joined Mar 2011
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #1 on: January 20, 2013, 10:58:16 pm »
Really looking forward to some educated replies to your question lynnandrob, I have the same idea and needs as you but not a clue where to begin storing power.
Pay our politicians minimum wage and watch how fast things change.

mab

  • Joined Mar 2009
  • carmarthenshire
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #2 on: January 20, 2013, 11:43:31 pm »
OK, another difficult question  ::) .

The 'best' batteries are made by Rolls/surette but they're not cheap.

If your looking for a larger battery (300Ah+)  then the general wisdom is that forklift batteries are a good value, robustly constructed deep cycle option - these are used by most off-gridders (I think).

Historically sealed AGM batteries 2nd hand from UPS's have been a good value source of deep cycle batteries, but nowadays they seem to be quite pricy for 2nd hand, and you've got the added complications of charging sealed 'valve regulated' batteries. If you are keeping the batteries in your house then AGM are best as they don't (normally) leak acid or vent explosive gasses.

If you're new to off grid power and battery manamgement I would recommend going for cheaper batteries the first time around - that way if you make a mistake and damage them it won't be as expensive. Also recommend a battery charge controller with undervoltage disconnect - which will protect the battery up to a point.

lynnandrob

  • Joined Jan 2013
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #3 on: January 21, 2013, 07:45:23 am »
hi mab,

thanks for the reply,yes im new to off grid living and dont have a clue when it comes to 12v batteries/battery banks.ive being doing a bit of research so i can have power at a off grid property that i own but im getting conflicking feedback with regards to setup and size.this link is to a diagam of what i think is needed from what knowlage i have gained so far,

[img=http://s20.postimage.org/9g4rqttnd/2_solar_panel_battery_bank_setup.jpg]

but i still dont know what AH is,is it the charge of the battery when full or is it the amount of charge it releases in a set time (eg-120ah battery will release 120ah in a one hour period).ive being looking at the trojon batteries but they go from 12v-34ah to 12v-120ah and im not sure which is the battery/batteries id need.
below is a reply i got from another site however i ve now found out it is mainly usa/canada users and they have a differant setup and possibly more sun.
----------------------------------------------------------------------------------------------
The system that you gave the specs for looks nice. Under extreme conditions, the Sound Bomb (With the twin pizeos singin') would consume ~2 aHr/24 hours. In armed/stand-by.. .264 aHr.. *Alarm state.. .312 aHr.. (Plus the sound bomb)*

It'll work from a 12 volt battery with ease. Worse case scenario, it would use ~4 aHr/day! A small marine deep cycle battery, a 30 watt panel, and an ElCheepo charge controller and you wouldn't need to touch it. Ya gotta have a little sunshine there sometime during the day..

Most standard marine deep cycle batteries are rated ~60 aHr. The 25% safe discharge level would be ~15 aHr. In stand-by mode, a fully charged battery would last over 50 days! The sound bomb is what sucks the juice. With the sound bomb screamin' it would still work for ~4 days..

If you're going to be there once a week, just use a set of jumper cables and charge the battery with your vehicle. That should cover things until ya come back next week..
----------------------------------------------------------------------------------------------

these are the things that will be run of the system that really need to be connected ( not tv)and their power useage's are
security cameras-10ah
alarm-13ah sound bomb 80ma(what is ma?)
house lights 11w each -maybe 5/6 used at any one time and only on a night(max say 70w)
security spot light 4 lights x 3w each on sensor's so only one or two will be on at any given time when movement is detected.
heating pump for the cental heating -0.38a ( only used when we are there )
tv - 36w

all advice and diagrams are greatly recieved

rob

mab

  • Joined Mar 2009
  • carmarthenshire
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #4 on: January 21, 2013, 11:47:20 am »
OK, the basics


A/Amp / ampere -  is a measure of electrical current - a large load will draw more amps and drain the battery more quickly.


mA is milliamperes - 1/1000 amp.


Ah stands for amp-hours - literally amperes x hours is a measure of battery capacity; a 100Ah battery is rated to supply 1A for 100hours, or 10A for 10 hours, 100mA for 1000 hour, etc to 100% discharged. in practice though, battery efficiency falls with higher amps so a 100Ah battery will last for more than 100hrs at 1A and a lot less than 1Hr at 100A. For this reason batteries are rated for a specified time; e.g. 100Ah at the 20Hr rate, meaning it will provide 5A for 20Hrs.


When sizing your battery, you have to guesstimate what your typical daily Ah draw is and how many days you want your battery to support between charges (assuming the sun doesn't shine everyday where you are). Also, as stated previously, you can't use the full rated capacity of the battery unless you are prepared to replace it every year.


when it comes to re-charging, bear in mind that a battery is typically around 80% efficient so if you've taken 10Ah out of the battery, then you need to generate about 12Ah to recharge it.


The drawing looks OK, but is for a larger system where you're using an inverter to supply the loads - that's OK but an inverter is at best 90% efficient and they typically draw 1A even if there's no load on them, so if you want to use an inverter 24/7 you are talking about a large battery, and solar array.


I hesitate to direct you to another forum (sorry dan), but really for research into this subject there are a couple of forums that have a lot of info on off grid living, and it would take a long time to relay it all here.


www.fieldlines.com


is a US based but quite multinational site which was started by folks living in remote areas where grid supply wasn't an option.


http://www.navitron.org.uk/forum/


is a UK site and whilst it has a lot of 'grid-connected' renewables people, there are quite a few off-gridders & 1/2  and 1/2 like me, and folks are familiar with UK weather.

lynnandrob

  • Joined Jan 2013
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #5 on: January 21, 2013, 01:56:56 pm »
hi mab
thanks for the links ill check them out later,
from what i can make out ill need at least two 120ah batteries just for the
security camera system (10ah)
alarm (13ma+80ma if triggered) lets say 0.1ah
am i right in thinking this will reduce the batteries to 50% in 24 hours ?
ill have a look on the other sites about amp/watt/volts as i need to know what 100w of light bulb power is in amp-hours.also what size panels to use,im presuming a 100w panel will only produce 100w in perfect condition with clear sky .so now i need to know what a 1000w panel will produce in amp hours and what it might produce on a cloudy day.
ill post my findings on here to help others who maybe thinking of setting up a simular system.

lynnandrob

  • Joined Jan 2013
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #6 on: January 21, 2013, 02:06:53 pm »
just being on a volts/watt amp converter that says 100w is 8.33amp if this is correct i think ill be taking a spare battery with us to run the lighting.

lynnandrob

  • Joined Jan 2013
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #7 on: January 21, 2013, 02:23:50 pm »
hi mab

tried joining the navitron forum but i cant get past that stupid anti-bot puzzle so it looks like this forum is stuck with me and my annoying lack of knowlege. :excited:

mab

  • Joined Mar 2009
  • carmarthenshire
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #8 on: January 21, 2013, 08:25:49 pm »
yeah they can be difficult to join - I ended up sending an email to them to set up a login.

watt=amps x volts for DC so yes 100w @ 12v is 8.33A

IIRC you cctv thing was 11w so ~ 22Ah/day if run directly off the battery; if run via an inverter and power supply (as per the diagram) then that's more like 50Ah/day. So es that'll take you down 50%/24hrs.

as to how much a panel will produce on a cloudy day - how long's a piece of string? They will produce something as long as it's daylight but there's a a big range of 'cloudy' from hazy sun giving 30-50%, bright overcast 10-25% down to dull grey <1%.

The fact is it's almost impossible to be 100% reliant on solar in the UK in midwinter and most people try to have something else (wind / hydro) and still end up firing up the backup genny occasionally.



lynnandrob

  • Joined Jan 2013
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #9 on: January 21, 2013, 10:14:26 pm »
everyone seems to go on about cheap solar setups but from my callculations things are far from cheap.

with 30w kit being around £80.00
and 100w kits around £200.00/£250.00 (£400.00 just for the panels,no fixings)
then the deep cycle batteries are over £100.00 each for the half decent 120ah ones,meaning its sure to put a dent in your wallet.

for the setup i need it looks like im going to have to spend over a grand just for the security side.
ive just worked it out - 12v -11ah - to be around 180w for the security cams/alarm and lights meaning ill need 4x100w panels (2 for day power usage and 2 for night power usage) just to power the batteries and probably another 200w for when it is cloudy and since the roof is facing almost east/west the panels wont be getting the full sun light so even more panels needed.
now im getting depressed :(.
please can someone show me a diagram for a setup that wont course the wife to kill me and will power 10ah/11ah worth of equipment. :(

lynnandrob

  • Joined Jan 2013
Re: which are the best batteries for a battery bank 12v-110ah or 12v-120ah
« Reply #10 on: January 22, 2013, 11:22:58 pm »
hi mab

i managed to join the navitron forum,but nobody gives advice on there just comments like,

I think it would be really daft to install anything of any value until someone is living there.
however good their intentions so far only one surgestion has made any sense and that was to have a battery bank that was topped up using a generator (which i sugested on this or back woods home forum)but i havnt heard how many batteries id need/best generator for charging or how to set it up.
here is the last part of the thread that i posted hoping someone can help.

but enought about that this was supposed to be about getting a power system that will power the security system.
all i need to know is how to do it,
for instance if i had 4x120ah batteries,how long would it take the system to reduce the power to 50% and how long it would take to charge back to full power using a blablabla generator or connect a blablabla solar panel system including blablabla and it will last  this long,or use twice as many batteries connected to this and this will happen.wind power is out of the question so it will have to be solar or generator powered.
please bear in mind im a complete novice when it comes to this sort of stuff so i would need diagrams/pictures to show me how to set it up.
any advise you or other members can give would be great,so far ive joined 3 forums and apart from the knowlege ive gained on here im still no closer to getting power to the house,althou all the forums seem to say it would need lots of solar panels and kit to just to run the security system.
 
SMILEY BUCKET im not sure if your still following this but it looks like we'll have to go with a generator setup

 

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