Biggest 110 Deep cycle possible?
 

My Optima Red Top and Yellow Top Batteries are up for renewal.

I currently run a 40W Solar panel, a National Luna battery management system and a Red & Yellow top Optima setup.

The red top apparently needs replacing, and I'd like a lot more capacity deep cycle wise for computer usage (and I'm likely to add a fridge as well).

Two batteries under the passenger seat is normal, but the National Luna system will allow a third battery which could be fitted behind the internal bulkhead.

Any suggestions for a good setup, or better batteries than Optima yellow tops?

You could replace them all with one of these
Odyssey battery PC2250
but breath deeply before you look at the price
It's the civilian version of this I've had one for a few years now that I bought surplus on German ebay. It has just started to fade on one cell and I'm going to have to buy another:(

I had a couple of ten plus year old wet cells (leisure batteries) that finally went to heaven and have replaced the pair with a single AGM (absorbed glass mat if I remember correctly). I had 100Ah with the two and now have 120Ah with one battery. The wet cells could only cope with about a 25% (so really only 25Ah) discharge and the makers claim the AGMs can cope with upto 80% (84Ah available) and still recover.

The AGMs are great as you can mount them anyway you like.

Downside is that I needed to fiddle with a charge sensor to make sure that the AGM does not overcharge, but no great difficulty as there was already a 75Amp solenoid from the vehicle starter battery.

Time will tell.

Make is Ritar.

I changed from AGM's to AC Delco.
Voyager® Battery | Batteries | Parts Information | ACDelco
My setup is 2x120 watt Kyocera panels and a PL-20 regulator , in Aust. with plenty of sun.
Check the charging voltage required for both types.

rolls series 5 batteries are pretty much the best batteries for deep cycling that money can buy. My experience of them is that even if you discharge them to near 100% they will still outlast most other batteries.

The payoff is that they achieve this through extremely thick plates and so as well as being massively heavy for their rated capacities, they are also extremely expensive.

If you look after them and do not discharge them below 50% my guess is that they will outlast the vehicle. Having said this, if you understand how to look after any battery it can be made to last a lot longer than one would expect.

A cheaper solution to using expensive batteries would be to use cheaper batteries but add equipment that will assist in ensuring that your batteries are able to be fully charged, not over discharged and not over charged.

A decent battery monitor that monitors amps in and amps out with a big shunt will be able to tell you accurately what level of charge your battery is at and will enable you to cut off energy users when you reach 50% discharge. This will be enough to massively increase the lifespan of your batteries.

Getting intelligent charging devices that enable you to charge you batteries beyon dthe 70% limit that is practically reachable with a standard alternator or solar regulator, will increase the usable battery capacity and make deep discharges less common. Sterling make some cheapish battery to battery chargers that use a standard 4 stage charging cycle to get your batteries to 100% charge in less time. Using an MPPT regulator on your solar cells will optimise their power output and so you will get mroe out of them

Thanks for the feedback:

I should perhaps have pointed out that I don't understand the maths of how all of this works - so any comments pointing how much extra grunt I would get compared to a single Yellow Top would be useful. I could always just put two Yellow Tops in parallel if my (older model) National Luna system allows that??

silver G,
They look good, but I'd prefer not to place 100% of my trust in one battery - having two that can be started off if the one goes belly up seems to make sense.
Would two of these fit under a 110 passenger seat?

RogerM
Slightly confused on this whole subject, so apologies for the dumb question - but AGM is a type of battery rather than a brand/model? If so, are there any particular brands models that are highly rated and what advanatges would a AGM have over the optima's?

ivanll
Why? Cost? better performance etc?

nickdisjunkt
"Getting intelligent charging devices that enable you to charge you batteries beyon dthe 70% limit that is practically reachable with a standard alternator or solar regulator, will increase the usable battery capacity and make deep discharges less common."

I think the National Luna system I have is quite good - though I struggle to use my 17" laptop for more than 3 hours (heavy processing, large screen etc doesn't help).

Any more thoughts on this...?

Not recommended
 

Hi Darrin,

We bought an intimidator battery, which is AGM (absorbed glass mat) and it has given us nothing but trouble.


I know very little about battteries and wasn't really given any additional imformation on this battery, so I could have ruined it myself. One thing that was the death nell of the battery was we put it on trickle charge, which apparently is a big no no for AGM. You have to buy a seperate charger.

Good luck

Hi guys

I'm no expert on batteries, but I remember a long conversation (over a pint or two) with the South African fella that owns eazi awn.

He tried to explain to me why the use of deep cycle batteries in an overlanding application does not work (in his opinion).

The basis of his argument was that the normal stop start of daily travel does not provide the time necessary for an alternator to recharge a deep cycle battery.

Deep cycle batteries will of course tolerate being run flat and then recharged, however the time to recharge a deep cycle is much longer than the 8 or so hours of driving the next day.

My own experience with:

- a deep cycle battery/national lunar split charger/minus forty fridge -

did seem to confirm this.

It was ok for the first discharge, but thereafter it never seemed to recharge.

Other travelers with a similar system but with a 'normal' battery always seemed to have their fridges still running when my 110 amphour battery had packed up. - perhaps because their 'normal' battery recharged quicker??

It could well be that the addition of solar panels will provide the necessary extra support to prevent the deep cycle from discharging too much in the first place; and supply the extra recharging oomph (technical term) to bring the charge back up.

However, could it be argued that if you have sufficent solar panel wattage to run the toys, then a deep cycle is not necessary - you might just as well have an ordinary battery with the low voltage protection system that the national lunar split charger provides.

If the eazy awn guy is right - deep cycle is not the solution; better to find a balance between toys and solar panels.

As I said at the beginning I'm no expert - I might be talking crap

John

The Optima Yellow top deep cycle are fine but limited to 75 Ah capacity.
I choose the AC Delco as it is also a deep cycle battery but it has 95 Ah capasity and was therefore better suited for my purpose as a house battery.
I have 2 of them in parallel, so there is enough capacity for a few rainy and overcast days.
The Voyager's were cheaper than the AGM's they are also lighter in weight.
But most important the Voyager like the Yellow Top can be charged directly from a normally voltage regulated Alternator which can be between 14.4 to 14.7 Volt.
It is not recommended to charge an AGM battery above 14.2 Volt this is why they require a Regulated battery charger.
A good solar regulator can be set to charge a normal Lead Acid battery( starting battery) or AGM's and Gell cells. But it should only charge one type at a time.
Short and to the point.
Normal lead acid batterier and deep cycle batteries (not Gell cells)can be charced from the same source.( alternator or solar regulator)
AGM's and normal lead acid batteries should Not be on the same charging source at the same time.
There are many good information on the different battery types and their specific charging requirement on the net.

Quote:

Originally Posted by chickcharnie (Post 215975) Hi guys

If the 8 hours of driving does not recharge your batteries then the problem is definitely not with the batteries, it is with the charging system or the energy users. The easiest way to make sure that 8 hours is enough time for full recharge is to use less energy and discharge the batteries less each night. If this is not possible then you need to improve the charging system. I am not familiar with the National Luna unit but any dc to dc voltage regulator which does a decent 3 or 4 step charging system with a bulk, float and absorption stage will massively increase the rate of charge; the sterling units are certainly good value and are worth considering if the national luna doesn’t do this. These units are obviously at the mercy of the alternator output though so while they maximise the available power they are not substitute for putting a bigger (or even a second) alternator on the vehicle. I decent alternator with a decent voltage regulator will be enough to power all but the hugest auxiliary battery banks if you are driving for 8 hours per day but if this is still not enough, then one or two big 200w panels will help.


Most batteries that call themselves ‘deep cycle’ will certainly not tolerate being run flat regularly. The only batteries that can cope with total daily cycling from 100% to 0% are true traction batteries such as those used in rechargeable forklifts and as I mentioned earlier these are both heavy and expensive; not to mention the fact that they usually come in 2v units which need to be seriesed up to the desired voltage. The speed at which a battery can be recharged is a function of the amps that the charger (the alternator) is putting out and the voltage difference between the charging source and the battery. The set and constant voltage that an alternator puts out can reasonably charge a battery to 70% or so but after this point the voltage difference between the battery and the alternator gets so small that the charging rate drops off exponentially, to counter this an intelligent charger uses a higher voltage which will drop back at an appropriate point. 70% might seem adequate but unfortunately this is a misleading way of looking at it; a regular deep cycle battery is not deigned to be discharged below around 50% on many occasions and indeed the voltage gets so low beyond about 40% charge that most equipment including inverters and fridges will fail to operate. Effectively this means that your 100ah battery is only able to use around 22ah! Using an intelligent charger should (unless you have in inadequate alternator) be able to charge the batteries to near 100% in 8 hours of driving and so you can more than double your available energy reserves.


Low voltage protection systems rarely assist in protecting the battery to a great degree, they are usually intended to protect the sensitive equipment from operating at too low a voltage and it is usually the case that by the time the low voltage sensor cuts power the damage is already done. Using a decent battery monitor and keeping an eye on it will be a much better solution, but unless you sort the charging side of things you will quickly see that your system is unable to cope with the demands.

The use of solar panels will invariable mean the need to cycle the batteries heavily as you will only be able to charge the batteries in the day. If your charging systems and battery capacity are unable (as is the case at present) to keep up with the energy demands than all but the most expensive batteries will have a massively shortened life-span and so my recommendation would be to use the cheapest ‘leisure’ battery that you can find.

I can wholeheartedly recommend the motorhome electrics book by Collyn Rivers if you want to learn more about getting the most from your low voltage eclectics system.

Sorry for the rant but there is a lot of misinformation floating around on the internet and elsewhere and mistakes with batteries are invariably expensive.

Great info, thanks - been looking for the justification to buy one of these inteligent chargers they aint cheap .:(

For a rant it was really informative

Thanks

PS Told you I might be talking crap!

John

Just to throw a spanner in the works, have you considered carrying a small silent generator instead of additional batteries?

The national luna as I understand them is basically a voltage sensing relay and so will not help with 'intelligent' charging. I looked at them when I was considering my split charge system. I ended up with a Sterling battery to battery charger and clipper marine battery monitor. The B2B can be set so that the charging pattern matches the type of battery. Temperature sensors are also included for battery, alternator and the unit also senses it's own temperature. I have found it to be superb and likewise the clipper which tells you amp/hrs consumed, current state of charge etc etc. I cannot really comment on types of batteries as I have only used the following with the B2B:
- cheap german (centro) cranking wet cell 110a/h. This actually drove the fridge and lights really well, but I ended up deep cycling it too much... Which shouldn't happen with the clipper, but does - if your car and fridge are used as a bar at outdoor bush parties...
- Caterpillar sealed wet cell calcium cranker 100a/h. Discharges much faster than the cheapo, but I know from other experience just how much abuse these batteries can take.

I have a AC Delco (branded as Deltec there I think) on the way coming from South Africa, and will probably just parallel it with the CAT to get about 200a/h. Both batteries share the same charging program on the sterling so we will see what happens. To be honest I lean towards the cheaper battery/better charging and monitoring school of thought. But on the otherhand a fit and forget type AGM I can really see the appeal.

I would say that if you are happy with the NL split charge then go with a decent cranking wet cell and a 100+a/h deep cycle wet cell. I would recommend sealed only for safety reasons - most sealed have a flashback arrestor in their vent. I once had a cap type wet cell detonate under my arse in the battery box of the Defender. I got a HELL of a fright but luckily no damage to anyone or anything other than the battery! At the end of the day for the price of a fancy agm you can get a lot of wet cells...

It seems to be a big complex subject this black art of battery stuff. Our highly qualified electrical engineer looks at me like I am from Mars when I start asking him about multi stage charging - but then he checks a battery condition by shorting it out while the caps are off and it is bubbling away :nono: I turned and ducked when I saw that!!!!!!!!!
It seems common to the internet that battery threads generate some big debates.
Gil

Ok, here we go again ;-)

The existing system has been fine, no problems over 8 years of use, except a lackof capacity, so I'm leaning towards just replacing the red and yellow top optima's running through the NL system as it currently is (Optima's seem quite cheap bang for your buck?).

Then adding a third battery - a huge deep cycle battery to run the (new) fridge(?) and as a backup for computer use etc.

My solar panel has a regulator and a switch so I can charge any battery I wish - I'll change this to also be able to charge the new (third) deep cycle battery.

My trusty overland preparation barn says they will be rig the third battery up to the alternator to be charged when the alternator is running. So when the engine is turned on it will start charging the red top starter battery and the third deep cycle battery - then after 5 mins the NL system will flick over to allow the 2nd deep cycle to be charged as well.

Two questions:

Is charging 3 batteries too much for a standard Defender alternator?

What is the recommended option for the third deep cycle battery? Size isn't a problem, weight and cost are a little etc

Many thanks!