deep cycle or not deep cycle

Submitted: Tuesday, Jan 18, 2005 at 16:40
ThreadID: 19571 Views:2081 Replies:7 FollowUps:8
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looking for a battery to run the invertor powering the lights maby a little tellie for the kids. done the homework and figure i am working on a 100 ah deep cycle. off to battery world and the 100ah is $210 furthur investigation and a cheap 80ah cranking battery is $79. if i get 2 80ah cheepies and use them i wont discharge them as much as a single 100ah but i am still in front by $50. question is am i wasting my time and money on the cheepies or cos the discharge % will be less will they hold up? also is $210 about rite for a 100ah deep cycle?
thanks in advance. greg
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Reply By: Member -Dodger - Tuesday, Jan 18, 2005 at 17:04

Tuesday, Jan 18, 2005 at 17:04
IMHO the deep cycle is the way to go. I have been using them for a no of years and they have always been better than an ord cranky battery.
Mainly because you can deeply discharge a deep cycle batt more times than a cranky battery and get away with it.
Try and get everything you want , lights etc and tele in 12v as these will then use less juice than something that runs through an inverter. My inverter uses power in it,s own right as does any inverter then you add the watts up from what you are using on 240 divide by 12 and you can then see what amps you are drawing from the battery, it's usually a lot more than you think.
Most tele's draw about 90 wats or so , one bulb incadesent 100 wats.
So far = 190 wats = 15 amps when on 240v plus the inverter draw.
12v tele draws about 5 amps and one 12 flouro (versa lite) 1amp total amps = 6 amp much less as you can see.
Lastly $210 for a d/cycle is somewhere in the ball park. mine was $150 three yrs ago.

I used to have a handle on life, but it broke.

Cheers Dodg.

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Follow Up By: greghud - Tuesday, Jan 18, 2005 at 17:56

Tuesday, Jan 18, 2005 at 17:56
yes i see the benifit of 12v gear i am working on about 30 to 50 amps between charges so i was working on the 100 ah deep cycle being run down to 50% but the cranking units down to 70% because of the extra capacity i am on a buget but hate to waste my time.
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Reply By: Member - Alan S (NSW) - Tuesday, Jan 18, 2005 at 17:07

Tuesday, Jan 18, 2005 at 17:07
Not sure if this helps or just adds to the confusion:
I've just installed a dual battery system and have used a cranking battery, $100 on sale for a 700CCA from super cheap, its a bosch and comes with a 2 year warranty. The cranking battery charges up real quick and if I stuff it up by discharging too much and too often I can replace it under warranty or in two years time buy another one (cheapy) and I'm hoping that this arrangement wil last me longer than one deep cycle....
AnswerID: 93806

Follow Up By: greghud - Tuesday, Jan 18, 2005 at 17:40

Tuesday, Jan 18, 2005 at 17:40
thats my theory to.
also if i use 50amp b4 recharging thats 50% if its fully charged but with the 2 cheepies its only 30% so not working as hard?
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Follow Up By: Noosa Bushtrackers - Tuesday, Jan 18, 2005 at 18:17

Tuesday, Jan 18, 2005 at 18:17
Alan,
Just be careful with warranty on Batteries. I found that the larger batteries are in a different warranty bracket to the smaller car type ones and only have a 12 months warranty.

We found out when we went to make a claim on a truck / 4WD sized battery that was a crank type and had been using it as auxiliary battery to run Engel fridge. We apparently ran it down too far because we didn't have anything in the line turn it off as the voltage drops, and stuffed the battery. They wouldn't recognise the warranty until the selling outlet pointed out to them that they hadn't even made him aware of this lesser warranty period, and they then replaced the battery.
Crank batteries don't last very long at all when you discharge them too far too often.
Brian
Doing it tuff, Towing a Bushtracker.

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Follow Up By: Member - Alan S (NSW) - Wednesday, Jan 19, 2005 at 10:23

Wednesday, Jan 19, 2005 at 10:23
Thanks for the tip Brain. I'll check again but i'm almost positive that this battery has 24 months warranty, in fact I'm sure there is a sticker on the battery itself stating the same.. but I'll check just to be sure....
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Follow Up By: phil - Wednesday, Jan 19, 2005 at 15:49

Wednesday, Jan 19, 2005 at 15:49
I have just bought a Exide Extreme N70 size for $116 at Kmart where they are on special now. It has a 2 year replacement warranty if it fails a standard battery test. (whatever that is).
The Extreme is a cranking battery but often recommended for second battery installations. It supposedly has vibration resistance and other features for 4WD use.

Recharging deep cycle batteries in a reasonable time is difficult. It may take many more hours than you will be driving to replace the charge. Cranking batteries accept a much larger charge current at normal vehicle charging voltages.

Phil I
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Follow Up By: greghud - Wednesday, Jan 19, 2005 at 15:56

Wednesday, Jan 19, 2005 at 15:56
phil,
did the battery have a stated amp hr rating?
at 2 years thats not bad and the charge rate is a nother good feture
would rather buy a name brand and the 2 yr warranty coz kmart arnt going to argue. good tip
thanks, greg
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Follow Up By: phil - Wednesday, Jan 19, 2005 at 16:37

Wednesday, Jan 19, 2005 at 16:37
The Extreme N70 size is 80AH or 150RC (RC is no of minutes at 25Amp before flat) The AH rating is at a lower current, so is larger than what you calculate from the RC (which is 62.5 )
I think this is about as much as you will get in that size case.

Phil I
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Reply By: Member - Jeff M (WA) - Tuesday, Jan 18, 2005 at 19:03

Tuesday, Jan 18, 2005 at 19:03
I know that Agparts around the corner from work in MidvaleWA (a farm supplies shop) sells calicium to calcium 105amp/hr deep cycles for not much more than $120. Worth looking around at some alternative suppliers to the 4wd/camping battery world style chains I reckon.
AnswerID: 93828

Reply By: Wok - Tuesday, Jan 18, 2005 at 19:57

Tuesday, Jan 18, 2005 at 19:57
Greg,

Is your figure of 80Ah for the cranker at the C20 discharge rate? I haven't come across N70 size with that sort of performance [mostly around 55Ah]....especially at $79!!!!!! Details of this cheapy?

If your figures are correct, then you have gained because your current drain is lighter for the 2X80s and you get more effective Ah then 160. If space & weight isn't an issue its the way to go..........just double check those specs again!

cheers
AnswerID: 93836

Reply By: Wizard2 - Tuesday, Jan 18, 2005 at 20:01

Tuesday, Jan 18, 2005 at 20:01
When we fitted the dual battery system at ARB they recommended and fitted a Hybrid (700 CCA and 80 AmpHr). I've had it in now for 2 years without a single problem.

It powers the caravan, the CB and fridge in the car. Having lived in Darwin for 2 years we heard stories of shortened battery life due to the heat and humidity. Haven't seen any evidence yet.

Deep cycles are designed to be completely drained flat and recharged a number of times.

Most 12 volt electrical devices (inverters, fridges, etc) have safety cut offs that stop the them running when the voltage drops below, say 10 volts as an example, as a protective measure. My inverter starts beeping at 10.5 volts, then will shut off. My Waeco will shut off if the voltage drops too far.

IMHO unless you can be sure the battery is to be completely drained flat and recharged then why pay for it. I would opt for a heavy duty truck battery as described in previous replies.

Wizard
Prado TD
Jayco Freedom
Gold Coast
AnswerID: 93837

Follow Up By: phil - Wednesday, Jan 19, 2005 at 16:41

Wednesday, Jan 19, 2005 at 16:41
By the time a cranking battery reaches 10.5 volt it is well on the way to being stuffed because it is fully discharged. They don't like it and it reduces life drastically.

Phil I
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FollowupID: 352912

Reply By: Mainey... - Tuesday, Jan 18, 2005 at 21:28

Tuesday, Jan 18, 2005 at 21:28
Greg,
Definitely get the two 80a/h Cheepie’s, their specs are as you have stated 80 Amp Hours each, so their cost is not relevant other than to say they are inexpensive...
I have been using the same two 80a/h Deep Cycle batteries wired in parallel for 4 1/2 years now and without any hassles.

How are you planning to recharge the batteries in the bush ??

Searching the web for actual battery manufacturer’s recommendations on using Cranking v Deep Cycle batteries to power auxiliary items will confirm the above.

the link below may also be of some interest->
http://www.uuhome.de/william.darden/
AnswerID: 93847

Reply By: greghud - Wednesday, Jan 19, 2005 at 15:29

Wednesday, Jan 19, 2005 at 15:29
i have run from the main batt to the back of the car with 100amp cable then anderson plug to the van batterys are to be in the front of the van so all up bout 6 mtrs with 1 plug at camp pull the anderson and i wont flatten the car but during the day driving it will charge and at powered sites i can run the charger to bring it right back up dont expect to go longer than 2 or 3 days at the most between access to 240v and i am getting 13.5v at the test battery in the van now off the car altenator. i am heading off for 9 weeks so it will be a good test.
the specs about the battery are not confermed becouse i havent been back there yet. but i think it was about the size of a n70z maby a bit bigger? not realy a prob coz the space is there for it.
AnswerID: 93939

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