Thread: Battery Discounts for Aulro members

Well I called Super Charge in Moorabin today to get a price on the Maintenance Free Super Charge Gold battery to suit the Defender. I needed a bettery for the SIII, but figured I'd get a new one for the Defender and put one of the Defender batteries in the SIII.

I'm not sure the guy in the Moorabin store knew about the discount, but when I mentioned it he quoted me $135 for the battery (RRP $195).

I went to get it, but found it was too much of a squeeze with the 2nd battery and the relay and the SC80 and a fuse box under the seat. I got a smaller 670CCA battery and he tested the 2 batteries I had in there. Both of the batteries that came with the Defender were deep cycles and one was a bit of a dud- no wonder I needed to switch in the 2nd battery to start the car if it'd been sitting for >3 days, not to mention that prolonged winching got a little slow. Anyway, the good Deep Cycle battery was too tall to fit in the 2nd battery posi, so I bought a 60 AH Deep cycle battery too. All up $200 for the 2 batteries.

I'm very happy with the service, and I'm set to go winching tomorrow - (hopefully I won't need the winch).

I'm pretty sure the 90AH Deep Cycle will be okay to crank the 2.25 petrol.

I've been looking for a replacement for the County. Currently has a 700CCA in there from when I brought it with a smaller 270CCA for the second aux battery (the 270CCA is actually the same size as the 700CCA).

Went and got a Bosch B67 but when I got it home found it was only 480CCA. Did some browsing and found the Century recommended model for the County is also only 480CCA.

What models are suitable for the County 110?

Here are a few types from the SuperCharge range of batteries
STARTING TYPE
MF50, 600 cca, 235L, 172W, 206TH...TH= total height
MF80D26L, 670 cca, 265L, 172W, 228TH
MF95D31R, 760 cca, 305L, 172W, 228TH
MF31-931, 950cca, 330L, 172W, 235TH

DEEPCYLE/STARTING hybrid
MRV50,650cca, 80ah, 265L, 172W, 28TH
MRV70,700cca, 105a/h, 305L, 172W, 228TH

Thanks Brad for starting this thread up. I came across it as I found the existing start battery dying in my V8 Disco - if the vehicle sits for a week it needs a charger on the battery to be able to start reliably and it's been using water which often indicates imminent failure, probably due to rising internal resistance and hence greater heating.

The old start battery was a Century fitted in 2000 by the previous owner so I can't complain about its life.

I visited the Supercharge warehouse in Tikalara St Regency Park in Adelaide and they were happy to give me a trade price on a start battery and an auxiliary battery, (the existing one is serviceable but losing capacity so I'll relegate it to the camper trailer).

I decided to go with expanded Calcium grid technology batteries for both applications and fitted a Supercharge Gold MF75D23R ($161.26) for the start battery - as is listed on the Supercharge web site for Series I Disco's. It's rated at 65AH and 610 CCA.

The only hiccup was that they gave me a D23Left with the terminals round the wrong way on the initial visit and I didn't discover the problem until I tried to fit it at the weekend - I had to make a return visit on Monday and they happily swapped it for a D23Right.

For the auxiliary battery I chose to replace the Century 50AH deep cycle battery also installed in 2000 with an Allrounder which is also Calcium and is rated as both deep cycle and starting (as opposed to the Amp-Tech which is a deep cycle battery) on their recommendation - it's a better choice if I need to use it to jumper to the start battery in an emergency. It has a useful pair of bolt posts (8mm I think) beside each lead terminal for attaching eye-lugs.

I was able to shoe-horn an MRV50 ($206.69) which is rated at 80AH and 650 CCA into the passenger-side space - it only just fitted though as you can see in the photo.

I spent Saturday fabricating some new hold-down frames from 20 x 20mm steel angle and help from my mate with the stick welder, and I had them powder coated. I picked them up this morning and finished off the job this evening. I used a paint aerosol cap over the +12V terminal on the auxiliary battery to keep it safe until I find something better.

I'm quite pleased with the way it all turned out and I was able to add 60% to the capacity of the auxiliary battery into the bargain. The Calcium batteries are a bit less tolerant to high under-bonnet temperatures than conventional batteries but I think it's a risk worth taking with the fairly high temperatures generated by the V8 engine. I'll let you know if I have any premature failures.

And, yes, I like using the marine isolators on the ground terminals - I've used them ever since I had a wiring loom fire in my Series IIA Landy back in ChCh 20 years ago. They may be inclined to be an unreliable connection (although I haven't found this to be the case, myself) but the benefit of being able to isolate the battery quickly and without tools in the event of a short developing is worth the risk in my opinion (Sod's Law - the only time I've ever needed an isolator was when I didn't have one fitted of course!).

Thanks, Brad, for your info and for taking my phone call from the warehouse to confirm the discount.

thanks graham for the post, i have just moved all the junk out of the way in my d1 to fit the second battery, and i too have a main battery with the second set of wing nut posts as the main batt. still not sure what to do with the second batt, but for now it will be the old batt from one of the other cars.
am using an SC40 from TRAXIDE TRONICS [drivesafe on this forum] to control the loads.

Graham
i fitted a MRV87 and a MF 31930 into the front of my rangie these are the bigger case batterys and required a bit of shoe horning but fitted no probs the allrounder cost me 185 and the goldie cost me 170 i got them from the wearhouse here in newcastle sofar the goldie is goin good tho im a bit sus on the allrounder as it seems to be a bit lacking on what its spose to do as i ran the fridge on it the other day and it only ran the fridge overnight and was flattened so im doing a few more tests on it and if it dont passits goin back for a new one

Hi Lokka,
I'm not been able to fit a longer battery into the passenger side due to the ignition module and coil support bracket which has been relocated to the radiator end of the space, but I presume you don't have that impediment.

So the MRV87 is rated at 120Ampere-Hours ie you can (theoretically) draw 120A for 1 Hour or 1A for 120hours. This isn't quite true in the real world since very high discharge rates tend to reduce the overall capacity a bit so discharging a real 120AH battery at 120A might actually cause it to become fully discharged in, say, 50 minutes. That's why the capacity rating is usually specified alongside a nominal discharge current or a time which implies a discharge rate.

On this last point, the Supercharge web-site has me confused as it specifies the MRV87's "20AH" capacity as 120AH. Perhaps someone can explain the use of AH (Ampere-Hours) in this context for me, but I suspect it really means at the 20 Hour rate the capacity is 120AH. In other words, discharging the battery at 6 Amperes, the battery will survive for 20 hours and will therefore have a capacity of 6A X 20H or 120AH.

So, I think that if you discharge this battery at a rate near 6A, you can expect a capacity of 120AH. If you discharge it at a higher rate, it will likely exhibit a lower capacity - for example at 12A it might only last for 9.5Hours (rather than the 10 Hours you might expect) so you get an effective capacity (at that discharge rate) of 12A X 9.5H = 114AH.

To get to your fridge (finally) my point is that the actual capacity will depend to some extent on the current drawn by the fridge (as well as the battery temperature for that matter). I'd hazard a guess that an average fridge (if there is such a beast) runs at 4 to 6 amps when the compressor is running, and it doesn't run all the time. So the current draw of the fridge is also going to depend on the thermostat setting and how full the fridge is and how well thermally insulated it is.

To asses the capacity of the battery with any kind of accuracy, you need to measure the current draw with an ammeter (let's assume 5A) and sit with the fridge for a while using a stop watch and assess its duty cycle (compressor On time divided by time from compressor switch-on through switch-Off to next switch-On). Let's assume the compressor runs for 5 minutes and one complete cycle lasts 10 minutes (so I don't have to use a calculator). That's 5min/10min which is 1/2 or 50% duty cycle.

Now drawing 5A at 50% duty cycle is equivalent to drawing 2.5A continuously (5A X 1/2 duty cycle = 2.5A).

So drawing 2.5A (average) from a 120AH battery, the battery should last for 120AH / 2.5A = 48 Hours. (In fact allowing for the on/off nature of the fridge and the fact that the current draw is lower than the 20Hour rate of 6A, it should really last a smidge longer.)

Incidentally, another slight complication is defining where the end-point is: is it where the battery terminal voltage drops to zero? I doubt it. Or is it at ~10.8V which is more likely - can someone confirm this? That's going to affect the apparent capacity a bit as well.

So if my guesstimate figures are anywhere near right, and your 120AH battery is lasting less than 24Hours, I'd say there's something wrong with it.

Sorry that was so long-winded but there are quite a few complicating factors along the way.

One point I alluded to in the earlier post, which will affect battery life, is the under-bonnet temperature. Since I have a thermocouple probe for my multi-meter I decided to do some quick checks today after the run up Shepherds Hill Road.

With the engine switched off and zero airflow, which I reckon will be worst case, I measured a general under-bonnet temperature of ~65ºC. The driver's side start batter was at ~45ºC and the passenger-side aux battery was at ~50ºC. The radiator header tank was at ~80ºC incidentally. This is for a 3.9Lt V8 running on LPG. I'll let you know how the batteries survive.

Incidentally most general use electronic components are rated to 60ºC. This means that accessory electronics devices I've fitted like my Electronics Australia (JayCar kit) aux battery manager are running right at their temperature limit. That's one reason I'm thinking of swapping it out for a Traxide controller which I'm guessing will be built with higher rated components suitable for automotive use.