Deep Cycle Battery brands, types, systems & installations

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Campfish4x4 said:
Be careful with dc to dc 45 amp as most agm batts have a max of 30 amp charge input bigger is not always better unless your running multiple batterys
one of the notable differences ive found between LC & AGM is that AGM has a MAXIMUM charge current, whereas an LC requires periodic charge with a MINIMUM charge current (20-30% depending on type)
From reading on some 4wd & caravan/camping forums it seems a fair average is around 8yrs on AGM & beyond 10yrs on LC. Im not sure exactly when LC came to OZ, but I haven't yet found reference to anyone using them beyond around 10yrs ago.
This lifespan also varies a fair bit from the obvious fact that there are so many variables affecting any battery's life.
 
condor22 said:
Lead Crystal batteries can be fully discharged unlike an AGM, however there is a cost;
The advertised cycle life is;
6000 cycles @ 20% depth = 16+ years
3800 cycles @ 50% = 10+ years
1400 cycles @ 80% = <4 years if cycled at these rates every day.
So as you can see, the more you use of capacity the lower the number of cycles, however I've not found how long they last if dead flat.

Conversely an AGM
3000 @ 20% = 8.2 yrs (I got 10years out of my last replacement)
1300 @ 50% = 3.6 yrs
800 @ 80% = 2.2 yrs

So the mean difference is that you will get a similar life from a lead crystal @ 50% discharge as an AGM @ 20%. This means a smaller battery bank for a similar output and life approx. half. Or twice the capacity for the same size and life. Lead Crystal is cheaper per AH over life expectancy than either AGM or Lithium and you can use the same charger as an AGM although if you use a deeper cycle it will take longer to charge.

AGM = $$$, LC = +20-25% $$$ and Li = "A bank loan" :)

whilst AGM can be discharged quiet heavily, from what ive learnt is that they shouldn't be discharged beyond 50% to get the best life.
LC on the other hand are happy to be discharged to 80% (or more) on occasions.
Of the people I know running dual battery setups (AGM & Calcium), none ever or rarely discharge them below about that half charge mark.
It seems an LC in this scenario could easily have a life beyond 10 yrs.
It will also be interesting to compare how LC & Lithium last in similar environments & usage in 10-12yrs time. After having a lithium phone battery swell to a dangerous level I am very wary of lithium batteries

Has anyone had any experience with a Lithium Deep Cycle over several years yet to comment?
 
Theres quite a few caravaners running lithiums now dd,weight savings is the main benefit and recharge time and hefty discharge rate,i bought them above to go in my ute but i was gonna mount them in a small made box under the tray in front of the wheel wells,changed my mind because of summer heat and ventilation,there still not set up yet as i ended up mounting them in a big toolbox on the tray,toolbox is rattling to bits on the dirt roads so ive pulled it off for some major reinforcment at the moment and i need to fit a roof rack for a panel to charge them yet.
Think theyd be better in a van or camper instead of the back of a ute,straps linking them together unless well protected can be shorted easier then a normal battery,not sure if id buy them again as a car aux battery,camper or van i reckon yep theyll be very good,ill just be running a solar charger set to 14.2-4 i think it is max voltage,cant overcharge them,lithiums ok,there all around us in every electronic device we all use....
Those at 100ah compared to say a normal agm ya not far off 200ah of usable storage at under 15kg,the weights savings are crazy.....
 
that is good info CTX
the weight advantage for lithium is 1 of its best attributes
Power-to-weight ratio
Lead acid 42 Wh/Kg
Lithium 86 Wh/Kg

with the increasing use of Li batteries in home solar & electric vehicles, & a huge increase in lithium production, the next 5yrs or so should see a good drop in price.
 
I use optima batteries for the last 20 yrs i got onto them though a pilot in turbine thrushes (type of plane with turbine engines ,they put up with heat,vibration, and some deep cycling there's red top ,yellow top,blue and have certain uses,and use ctec chargers but no more than 10 amp compacity i pretty well live in hotest part of aus and ruffest roads and there reliable have a look at them
 
Always a bit tricky getting it right .
.Just ordered for the truck.3x300w solar panels..
45 amp Projector DCDC charger..
2x155 Amp..AMG batterys..Got 2 spare AMG in the ute we could hook up with them if needed..
100amp fuse blocks, fuse panel,rocker switches,Cig and USB outlets..Lots os 25 amp And 15 amp cable..
Waiting for the postman..
 
The problem child in the Truck is a top lid fridge, Wayco 45lt..Not a compressor motor..Is probably going to draw 10 amps..
Also running a 45 lt Wayco as a freezer..Draw 5-6 amps..
Will make ice in the freezer and put in the fridge to help..
Installing computer fans to help air flow around both..
Not using much other power and would expect to use truck motor most days..
Will put a couple of amp meters to check on whats going on.. :party:
 
Hi all,
A question without notice on dual battery installations.
Can someone explain, in simple english, why the need for DC to DC chargers?

Thanks in advance
 
This is pretty well explained.

DC-DC BATTERY CHARGERS EXPLAINED
By: David Cook, Photography by: David Cook

Date: 14.09.2015

A DC-DC charger keeps your caravans auxiliary battery system operating at peak efficiency for longer when youre off the grid. David Cook explains how and why.

DC-DC battery chargers explained
A DC-DC charger is effectively a smart-charger for your 12V system
When you start talking 12V electronics, I reckon half the audience switches off and the other half starts digging fox holes, ready for war.

The fact is, 12V electronics are confusing. It is supposed to be about 12V, but the batteries need around 14.4V to charge, are considered 100 per cent charged at 12.8V and only 50 per cent charged at 12.2V.

The confusion is compounded by various battery chemistries, all with different charging regimes and characteristics, and the fact that what works for one vehicles setup might not in another vehicle.

Then theres cable size, assessed in at least four different ways, and a steady flow of new technology. So theres little surprise vanners wanting to optimise their electrical systems but, beset by conflicting and confusing information, shy away hoping what they already have will do.

BATTERIES
For the purposes of this article, well refer to the batteries in our caravans as house batteries and those in tow vehicles as cranking batteries.

Like all batteries, these supply electricity for our lights, fridges, chargers and other electrical appliances. We can do this off the vehicles alternator while driving, off mains power, or via some third form, such as solar or generator, when off the grid.

Our house batteries are (or should be) different to cranking batteries. The former are designed to deliver relatively low levels of electricity over a long period. The most common house batteries are lead acid (deep-cycle), absorbed glass matt (AGM), gel, calcium and now lithium.

House batteries are rated by amp-hours (Ah) the theoretical capacity to deliver x amount of amps in an hour. In a 100Ah battery, for example, this equals 100A for one hour or 5A per hour for 20 hours. In practice, we shouldnt do that, because discharging a storage battery completely (except lithium) can shorten its life. The manufacturer-recommended level is usually 50 per cent (when the voltage reads 12.2V), though AGMs will survive happily down to 30 per cent (11.85V).

This means that, in a house battery system with one 100Ah battery, you have 50-70A maximum capacity.

CHARGING
Some travellers rely on a cable connection from their vehicles alternator-based charging system, with an Anderson plug to connect it at the hitch point. However, while it is possible to fully charge a battery off an alternator, because the rate of charge declines as the voltage in thebattery approaches that of the charging system, it rarely exceeds about 70 to 75 per cent, even after a full days driving. And because our house batteries are at the end of 8-10m of cable, along which you will get voltage drop, that can be even less.

So our 100Ah deep-cycle battery that ran down to 50Ah after a few days use may only return to 70Ah for our next nights camp, leaving us with a nominal 20Ah of useable capacity (70Ah minus our 50Ah minimum charge).

Fuel efficient low (or variable) voltage alternators found in modern 4WDs compound the issue, producing as little as 13.8V compared to 14.4V produced in earlier generation vehicles. Theres even talk of switching off the alternator once the cranking battery is deemed fully charged.

So what can we do?

BASIC SETUP
Many factors can assist. Firstly, limit losses by:

using decent-sized cable from the alternator to the house battery (minimum 6B&S/13.5mm thats close to a pencil in diameter) and replace any of the 6mm cable usually offered
using genuine Anderson plugs (not cheap clones, usually sold as Anderson-style plugs)
crimping and soldering all connections.
Secondly, install a DC-DC charger adjacent to the house battery.
DC-DC CHARGERS
A DC-DC charger is effectively a smart-charger for your 12V system. It isolates the house battery system from the alternator, so that the vehicles computer management system sees it as something like a set of lights. At the same time, it boosts the charge at the house battery from as little as 9V back up to 14.4V (or higher, if required) to maximise charging capacity, delivering it in stepped form, like your smart mains charger, achieving close to 100 per cent charge after a days driving.

Most DC-DC chargers also act as solar regulators, relocating whats traditionally been a separate item on your solar panel to a better position adjacent to the house battery. And these are no ordinary regulators, but maximum power point trackers (MPPT) that optimise your solar panels performance.

Most DC-DC chargers draw a higher rate of amperage from the alternator than would be supplied if you let the alternator push down the cable. This can be up to 40A or more per hour, quickly replenishing the house battery system.

Complete battery management systems (BMS) are new to the market and incorporate a mains charger, a DC-DC charger and MPPT solar regulator.

These generally come with a high-tech battery monitoring panel and, while expensive, are simple to install, requiring no post-manufacturer wiring between multiple units.

DC-DC chargers benefit from 6B&S/13.5mm cabling (the conductor, not the conductor plus insulation, which is how most cable is sold). They work with smaller cable, but as the voltage drop through smaller cable increases, the heat produced reduces its conductivity, forcing the charger to work harder, drawing more current and increasing heat. This can continue to the point where the demand exceeds the alternators capacity to supply. The energy dissipates as heat is wasted.

Installing the charger near the house battery overcomes much of that voltage drop, while adhering to the manufacturer-recommended minimum clearance assists in dissipating heat.

DC-DC chargers increase the likelihood of your batteries arriving in camp at close to a full charge, minimises damage to your house battery system from over discharging and, in my opinion, should be fitted as mandatory or at least offered as an option on every camper and caravan sold in Australia.
 
update: Im very happy with my system so far. Lead Crystal battery + Projecta 45A DC-DC charge controller + 100W solar panel
Im finding the solar panel more than covers my fridge on sunny days, and tops up the battery. I have a dual voltmeter on the circuit shows me battery & solar input.
I have a manual circuit breaker under the bonnet between the 2 batteries (for alternator charging), & i flick this in once a week or so to ensure ther battery gets a full current top-up as required. Im still procrastinating on whether or not to install the solenoid that I have .... I like manual operation on most stuff, plus still need a breaker/fuse anyway.
An interesting point on the LC battery ... my electronic diagnostic unit (analyses battery & alternator charging, & has proven correct on many occassions now) cannot analyse the Lead Crystal Battery, I assume due its different chemical makeup.
 
Ded Driver said:
update: Im very happy with my system so far. Lead Crystal battery + Projecta 45A DC-DC charge controller + 100W solar panel
Im finding the solar panel more than covers my fridge on sunny days, and tops up the battery. I have a dual voltmeter on the circuit shows me battery & solar input.
I have a manual circuit breaker under the bonnet between the 2 batteries (for alternator charging), & i flick this in once a week or so to ensure ther battery gets a full current top-up as required. Im still procrastinating on whether or not to install the solenoid that I have .... I like manual operation on most stuff, plus still need a breaker/fuse anyway.
An interesting point on the LC battery ... my electronic diagnostic unit (analyses battery & alternator charging, & has proven correct on many occassions now) cannot analyse the Lead Crystal Battery, I assume due its different chemical makeup.
Given your running a DC D.C. unit any specific reason for manually disconnection from alternator? Just curious?
 
a small point if you are buying a solar panel and DC-DC charger .

I have seen Solar panels claimed to be for a 12 volt system that put out up to 31 volts but some DC-DC chargers state their maximum open circuit voltage is 23 volts so check both specs before buying and before you install them.

From memory the CTEK 250D for example is 23 VDC solar input while Redarc is 36 VDC.

Do ya homework !
 
Jaros said:
This is pretty well explained.

BASIC SETUP
Many factors can assist. Firstly, limit losses by:

using decent-sized cable from the alternator to the house battery (minimum 6B&S/13.5mm thats close to a pencil in diameter) and replace any of the 6mm cable usually offered
using genuine Anderson plugs (not cheap clones, usually sold as Anderson-style plugs)
crimping and soldering all connections.
Secondly, install a DC-DC charger adjacent to the house battery.
DC-DC CHARGERS
A DC-DC charger is effectively a smart-charger for your 12V system. It isolates the house battery system from the alternator, so that the vehicles computer management system sees it as something like a set of lights. At the same time, it boosts the charge at the house battery from as little as 9V back up to 14.4V (or higher, if required) to maximise charging capacity, delivering it in stepped form, like your smart mains charger, achieving close to 100 per cent charge after a days driving.

Thanks for that Jaros.

An interesting read.

It's a concern that the author advocates both crimping and soldering a connection, especially in high current connections. (If I've misunderstood his statement then many others may also :/ )

My original question could have been better worded. I was referring to a dual battery system where both batteries are installed under the bonnet as I'd misread the OP as saying that was his intent. In my scenario, there is no apparent cost efficient benefit in fitting a DC-DC charger.
 

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