A couple of months ago I outlined the types of tests I would be conducting on a range of different battery types.
My first step was running the batteries through tests involving drawing down the batteries to 11.5 volts with a 4.6 amp work light and then recharging them with a CTEK 25 amp/240 volt battery charger.
After these tests where completed I was then to move on to the alternator based tests where I would put the batteries through the same testing process this time recharging them with the alternator in my 100 Series Landcruiser.
At the start of the tests I believed quite confidently that the first stage of our test (i.e. recharging the batteries with a 240 volt battery charger) would not show up much difference in the different types of batteries. I believed that the alternator test would be the test that sorted out the different types of batteries in real world conditions.
How wrong I was!
The reason for the battery charger stage taking so long is that the test results of the individual batteries have been that far apart that I’ve tested and retested to make sure of my results.
Another result that I’ve noticed through my continued testing is the significant drop off in the different types of batteries.
When the batteries where new they certainly performed much better than after I put them through repeated charge/discharge cycles. The repeated drawing down of the batteries to 11.5 volts and then recharging them has seen all the batteries drop off from their earlier performances, however some have been affected much more than others!
I have to admit that when I drew the batteries down I tended to leave them lying around discharged to 11.5 volts for a period of 8 to 36 hours before I could recharge them.
This is certainly not ideal; however it does replicate real world usage which is the goal of my tests, so I think this observation has been a very worthwhile part of my testing.
All of the different types of batteries where put through these test conditions, so at the end of the battery charger test we can really see which batteries will handle discharging abuse well.
This is a very important element for me as my batteries, no matter how hard I try, always seem to sit around discharged for a while.
The perfect example is my 100 Series Landcruiser with my 50 litre National Luna fridge/freezer in the back. I live about 800 metres from work so sometimes I hardly get to take the Cruiser for a long enough drive to get any charge into the auxiliary battery.
The good thing about the National Luna is I can set the battery cut out on the fridge to 9.5V, 10.5V or 11.5V. I really would not like to see any battery go below 11.5 volts especially for an extended period of time, so this is what my fridge is set at.
What I want from a battery is to be able to let it sit at 11.5 volts if I can’t keep the charge up to it, and then for it to be able to take charge well when it is available.
No battery is going to perform at 100% under these conditions, and if you can avoid them you should! However the real world isn’t perfect and these things do happen, so I want a battery that will cope. Currently I am using a no brand AGM battery that I am considering using on our portable power packs, that will be released onto the market over the next couple of months.
This battery has taken everything I have thrown at it and still performs well, which for me is a vote of confidence in AGM technology.
Another example is our hire fleet of camper trailers. Unfortunately not all hire customers care too much about the condition of the batteries in our camper trailers and there have been occasions where the batteries have been brought back dead flat.
Currently our hire campers come supplied with traditional lead acid deep cycle batteries; they have been through the abuse and seem to come back ok when reconditioned on a CTEK battery charger.
Before we changed over to the Cape York camper trailers we where hiring the Kimberley Kampers which came with Gel Cell batteries. These where only good for boat anchors once over discharged, and our bad experiences with them is why you won’t find them in my battery tests.
Gels are a great battery if you look after them; however they do not handle abuse well. AGM batteries have similar performance characteristics to Gels however handle abuse much better, and that is why I recommend them to my customers over Gels.
Overall in the battery charger stage of my testing I am very happy with the performances of the AGM batteries and marine start batteries. The traditional deep cycle and calcium type batteries really seemed to struggle.
But for now I’ve run out of time to finish writing up my results so I will follow up this email with part two and the individual results of each battery next week.
Kind Regards,
Brett Hooper
Kulkyne Kampers & 4WD
