I have a failed house battery & I am in the market for a new one. Could I ask those elec. techs. their opinion of the pros & cons of one larger AGM, as against two 100ah in parallel. I have an open mind on the subject & would value knowledgeable input. Thank you.
Terry
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Chris & Terry
3.2lt 4 x 4 Mazda BT 50, single cab chas with full alloy canopy
Me too, hope to be getting mine next week. I have decided to get a SuperCharge Allrounder, think thats what its called from Autobarn. $219.00. Might depend on the space where you are to put it. Mine goes into a boxed space at one end under the bed which is behind the drives seat. Might have to adjust one wall slightly to get the new one in. Decided on that brand as a lot of people have told me it doesn't take as long to recharge as a deep Cycle.
My knowledge of things electrical is extremely limited, but I would expect one 120AH AGM Deap Cycle battery would be a lot cheaper than say two 70 Ah AGM's. If one gives up the ghost before the other both have to be replaced or the new one will be brought back to the condition of the older one.
An All Rounder is a bit like having a bet each way. If your on a winner you only get paid for a place. It won't be a proper Cranking Battery nor a Deap Cycle Battery. If used as an auxilary battery to run things in the RV then a deap cycle battery should be the first choice as it will handle the constant discharge and recharge a lot better and thus have a longer life.
Note: The vehicle alternator will not charge a Deap Cycle battery 100%. You'll need a quality multi stage charger to do the job.
Cheers, Ozjohn I'm open to be corrected on the above statements.
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Retired Engineer, Ex Park Owner & Caravan Consultant. Holden 2.8 Colorado - Roma Elegance 17'6" Pop Top. Location: Mornington Peninsula Vic.
ozjohn I'm not going to correct you on your statement because I haven't a clue. But have been told the All rounder will charge up quicker and to the maximum, which you are saying the Deep Cycle wont charge to 100%. Now I'm confused as you say an all rounder is like taking a bet and only get paid for a place. Where do I go from here. I, being only a dumb female, thought I had it worked out from what I have been advised by so many different people.
ozjohn I'm not going to correct you on your statement because I haven't a clue. But have been told the All rounder will charge up quicker and to the maximum, which you are saying the Deep Cycle wont charge to 100%. Now I'm confused as you say an all rounder is like taking a bet and only get paid for a place. Where do I go from here. I, being only a dumb female, thought I had it worked out from what I have been advised by so many different people.
HI
OzJ basically has it correct
Batteries can be :
[1]pure starters give high currents for short time , & recharge quicker
DO NOT like to be heavily discharged or even 50% discharged frequently
[2]pure deep cycle
lower steady currents to 50% discharge on a regular basis
slower to recharge to full
[3] Hybrids a bit of each[1]&[2] but not perfect @ either
Just be wary all agm batteries are not deepcycle INCLUDING "FULL RIVERS"
The following is an edited paste of a recent post of mine on the techies forum covering this issue...
I personally prefer to avoid parallel connecting batteries but if doing so it's important that the batteries be identical in every respect including age. If one battery fails (even partially) both batteries must be replaced. If considering ordinary wet (open) batteries I'd suggest a couple of 6v 200ah batteries connected in series would be a better alternative, this would also be the preferred alternative for AGMs too but price and availability may be an issue. (note that two 200ah 6v batteries in series gives a total of 200ah at 12 volts (not 400, "you don't get nuthin' for nuthin'!")
When parallel connecting batteries, steps must be taken to ensure the load is shared exactly by both batteries. The best way to do this is to use heavy gauge cables to interconnect them, also in order to equalise the load, the wires connecting the battery bank to the load should be connected as follows...The positive wire to the positive terminal on one of the batteries and the negative wire to the negative terminal of the other battery. Failure to do this risks the possibility of shortening the life of the batteries.
I assume that the batteries are for the caravan and not aux batteries for the tug, and that they will be recharged from some or all of the following: .... solar panels, on board (240v) battery charger and/or charging circuit from the tug. A deep cycle would be fine for this application as the charging rate (time to charge) will be limited by the charging system or the length of the cable run from the alternator to the house battery.
Except I don't think Full River Batteries are as good as they once were, and can't understand how many can justify their premium prices.
OJ
If the batteries are installed in a parallel connected configuration I'd suggest this as a much more likely cause of reduced battery life rather than the quality of the batteries.
Also, battery life is dependent on both the number of discharge/recharge cycles and the depth of discharge. (as alluded to in OT123's post above)
Gel batteries give the best life in terms of cycles and depth of discharge but there are other considerations beyond the scope of this thread that must be taken into account before thinking about gels.
-- Edited by jimricho on Thursday 4th of August 2011 07:31:18 AM
Sorry jimricho, but could you expand further on your last parragraph? (there are other considerations beyond the scope of this thread that must be taken into account before thinking about gels.).
Regards Terry
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Chris & Terry
3.2lt 4 x 4 Mazda BT 50, single cab chas with full alloy canopy
Me too, hope to be getting mine next week. I have decided to get a SuperCharge Allrounder, think thats what its called from Autobarn. $219.00. Might depend on the space where you are to put it. Mine goes into a boxed space at one end under the bed which is behind the drives seat.
I won't buy into the chat about which is better, 2 small vs 1 large (I'd go for the 1 large as the best all round option unless you need to run a CPAP machine or something and need to guarantee at least one bettery is there), but I do have a word of advice for you.
A battery needs to be in a vented (to the outside) place unless it is one of the gel types thatdoesn't produce hydrogen gas as part of the charging process.
Hydrogen and the possibility of a spark from the vehicle electrics is not a good combination!
thanks for the heads up Joe, my initial request was the pros & cons re two large gels or agms as against one larger. Still waiting for a reply jimricho.
Terry
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Chris & Terry
3.2lt 4 x 4 Mazda BT 50, single cab chas with full alloy canopy
Sorry jimricho, but could you expand further on your last parragraph? (there are other considerations beyond the scope of this thread that must be taken into account before thinking about gels.).
Regards Terry
Happy to Terry, just didn't want to clutter up my previous post too much....
A few considerations re Gel batteries....
1. They can be damaged by excessive charging currents. I've seen a figure quoted as low as 5 amps for a 100 ah battery as a suggested charging current. Yes, seems a bit low to me too so check with the manufacturer's data to make sure.
2. They require a lower charging voltage than AGMs or flooded (wet) batteries so the charger must be suitable for gels (my Xantrex charger has a special setting for gel batteries)
3. They do not like high discharge currents (eg most inverters)
4. They are not suitable for charging from an engine alternator for both reasons 1. and 2. (unless steps are taken to limit the charge rate and voltage). They are not suitable for under bonnet installation.
5. They are ideal for stand-alone solar installations, such as street lights/signs etc, navigation channel markers, some communications installations etc, where they undergo a daily recharge/discharge cycle.
Note....These coments are generalisations and may not apply to every gel battery (I think "Haze" is one example of an exception).
Thanks jim, I have settled on an answer to the question of two large against one larger, (will go one larger), but only half settled on the question of gel v agm. Probably agm, but changing my mind a dozen times a day. Thanks for your input.
Terry
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Chris & Terry
3.2lt 4 x 4 Mazda BT 50, single cab chas with full alloy canopy
My two bob's worth from playing around with battery's for years.
Go a quality agm battery as big as you can handle as the large ones are very heavy but a 200 amp hr battery is still lighter than 2X 100amp hr battery's.
It is the physical handling of the large battery that is the problem.
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I was tired yesterday and I'm tired today betcha I'm retired tomorrow. he he.
My two bob's worth from playing around with battery's for years.
Go a quality agm battery as big as you can handle as the large ones are very heavy but a 200 amp hr battery is still lighter than 2X 100amp hr battery's.
It is the physical handling of the large battery that is the problem.
Yep! no argument from me on that one. 2nd choice would be the two 6v 200ah jobs. This is electrically identical to the one 200ah 12v one, In fact it is effectively one battery spread across two battery cases.
-- Edited by jimricho on Saturday 6th of August 2011 07:18:43 AM
According to the lady manager at Battery World, she and her husband do a lot of camping. They replaced their gel batteries with AGM and now they wouldn't use anything else.
Cheers. Pam.
p.s. Roll on "National Myrtle Day". (That's whichever day she goes home)
-- Edited by Travel Bug on Saturday 6th of August 2011 04:23:19 PM
