Deep cycle batteries.

briche · Guru

Deep cycle batteries.

Happywanderer · The Master

I will be interested too briche, as to types and prices for when I get my van and there is a need to renew.

Peter_n_Margaret · Guru

Why 2 @ 6 volt x 200Ahr and not 1 @ 12V x 100Ahr?

I would only ever contemplate AGM batteries, personally.
I have had good service from Fullriver and would suggest the DC series, but there are other good brands of AGMs on the market too.

Cheers,
Peter

jimricho · Guru

Peter_n_Margaret wrote:

Why 2 @ 6 volt x 200Ahr and not 1 @ 12V x 100Ahr?

I would only ever contemplate AGM batteries, personally.
I have had good service from Fullriver and would suggest the DC series, but there are other good brands of AGMs on the market too.

Cheers,
Peter

2 x 6V 200 ah will give a total of 200 ah at 12 volts..... 1 x 12 v is only 100 ah. total.

Maybe you're suggesting paralleling 2 x 12v batteries to achieve a total capacity of 200 ah. This seems to have become common practice with RV owners in recent times, probably not long enough for the life shortening effect of connecting them this way to become evident.

Brian's plan to use 6v batteries in series is the correct option. I'm aware that he comes from a technical background very similar to mine and is well aware that the practice of connecting batteries in parallel is never done in critical installations such as communication facilities where battery reliability is paramount. I am speaking from professional experience here.

Jim

bill12 · Guru

Really, what do you want to run? 200amp hr atr 12v is welding current, and I am a welder by trade!

jimricho · Guru

bill12 wrote:

Really, what do you want to run? 200amp hr atr 12v is welding current, and I am a welder by trade!

Hi Bill,

You seem to have a misconception here. We are not talking about the battery's ability to deliver 200 amps but 200 amp-hours. One amp drawn from the battery for 200 hours is 200 amp-hours. Ten amps for 20 hours is 200 amp-hours.

Amp-hours is a way of expressing the capacity of the battery. Amps (amperes to give it its full name) is a measure of the rate of flow (current) of electicity from the battery. If nothing is connected to the battery or switched on there will be no current being drawn, therefore there are no amps coming from the battery. If a device that draws (say) 10 amps is connected, the current (rate of flow) is now 10 amps.

Think of it like a water tank, amp-hours to a battery is like litres to a water tank. Amps to a battery is like litres per hour being drawn out of the water tank.

OK pedants, I know the story is a little more complicated than that, but let's keep it understandable.

briche · Guru

Well I did say that this topic may start some discussion. Thank you for your comments so far. As it has already been pointed out that the two 6 volt batteries of 200 or 100 amp hour rating in series is the same as one 12 volt battery. The benefit and it is a major one is that you don't have the problems that arise when batteries are connected in parallel. These problems come from that fact that when one battery starts to develop a fault, ie faulty cell, etc it will attempt to rectify the issue by drawing from the good one. In the end you run the risk of having two dud batteries, one due to it's faulty condition and the other in some level of discharge due to the power taken from it.

I must admit that on the surface it can be a little difficult to get your head around but believe me that's the way it's done in the battery industry. Sure there are problems with the whole battery bank if one battery develops a fault but you only have to replace that one. The best way to catch the issue before it reaches that place is to carry out regular battery maintenance ,say once a month, by checking the batteries and writing down the results. That way you will see the change before it becomes an issue.

Sorry this has been a bit of along winded but as someone who worked with batteries in the power generation industry for 27 years I know how and why batteries can be a bit of a pain in the neck if there not looked after properly and after all if you are intending to do lots of free camping like Cheryl and I are battery condition is a very important topic.

Thanks for your interest
Briche

BobnBev · Senior Member

Hi Like p n m I too use Fullriver AGMs and find them good value for money.. Have a look on flebay for the best price delivered.. I use 2 120amph 12 volt ,run a 190 lts Waceo 2 door fridge .. 400 watts sola ..all runs fine.. Good luck with it...Bob

Peter_n_Margaret · Guru

My appologies, I did mean 2 @ 12V, not one.

briche wrote:
These problems come from that fact that when one battery starts to develop a fault, ie faulty cell, etc it will attempt to rectify the issue by drawing from the good one. In the end you run the risk of having two dud batteries, one due to it's faulty condition and the other in some level of discharge due to the power taken from it.

We are a bit off the track here now, but the problems of paralling batteries are more theoretical than practical, in my view.
In the example you quote, if a 6V battery dies and you remove it from the bank, you have nothing useful left (only a 6V battery).
If a 12V battery is removed from the bank, you still have one good 12V battery left. That is good insurance, in my book.
I have run 5 @ 12V batteries in parallel for 5 years with great success as do virtually all other motorhomers with larger banks.
Fact is if you need more than about 200Ahrs, you will need to parallel them anyway otherwise they will be individually too big to move.

Cheers,
Peter

_wombat_ · Master (of Mischief)

I suggest you take your van to a place like Battery World or one of the big battery dealers and tell them what you want it for and they will advise the best brands, asking those sort os questions in a forum will always get conflicting replies, personally I have no idea about batteries so when mine go down I head to Battery World in WA, amd no I do not work for them

jimricho · Guru

I have experienced first hand the reduced life span of parallel batteries... nothing theoretical about that.

Once the batteries start to age they can do so at different rates so the two batteries are no longer identical, also steps need to be taken to ensure that the load is shared as evenly as possible.

Using 6v batteries in series is much the preferred option to get the maximum life from the batteries.

Feel free to parallel as many batteries as you like, it's your money, you may even get a reasonable life span out of them, but then again you may not.

briche · Guru

Thank you for all your comments and advice. It has been good to see thoughts and comments out there and once again it has shown me that this grey nomad community is one that looks out for each other and I thank you for that support.

Regards
briche

bill12 · Guru

Maybe I got that wrong. It depends on what you want to run. I have a 150amp/hr lead acid deep cycle as my second battery and a 120 amp/hr as my starting battery, and they run all my stuff , inc 55 ltr fridge, lights, fans etc. 200 amp hr is a lot .What do you want to run? I also have 3 -40watt solar panels, and the engine has a 70 amp alternator, which keeps it all charged up.I get up to 5 days before I have to start the diesel.The system works well.

briche · Guru

Thanks bill12, for your input.I will be looking foe something around the capacity that you have in your system as the loads and charging will be about the same as well.
I was originally asking of what brand of AGM battery has the runs on the board before I go out and purchase them but the discussion moved away from that. Our vehicle (landcrusier) that we have just purchased all ready has been fitted out for the second battery along with all the hardware that goes with all that but the caravan does not have batteries installed as the previous owner ran the van from the vehicle all the time.

As we are intending to do a lot of free camping I need to install batteries and charging system in place before we start out. Have sorted most of it out but have not decided to put sola panels on the roof or use a portable panel set. Seems to be one of those subject areas that is open to discussion.

Thanks for your input
Regards
briche