Amptech AGM Batteries

Discuss technical aspects of your 4WD with other owners, and share your opinions
Bazza_rips
Part of the furniture
Posts: 1488
Joined: October 29th, 2006, 8:39 pm
Location: Capelle Larba, Brisvegas

Unread post by Bazza_rips » January 11th, 2007, 6:12 pm

drivesafe, just another reason for me to mount it in the tray :D
Moderate amount of kit......... Still a bloody long list to go!

Who needs Bling when you've got Black sunnies?

Richo1951
Getting to know the place
Posts: 13
Joined: April 27th, 2007, 10:29 pm
Location: Mount Gambier

AmpTech AGM Batteries

Unread post by Richo1951 » April 27th, 2007, 11:18 pm

The one size fits all doesn't apply in most situations in life, and certainly not for power requirements when you are on the road, camping etc. I read with interest the different setups people have to keep their batteries charged and their beers cold. Most people seem happy with their various solutions.

I originally fitted a Redarc solenoid and used an Exide 75 Ah "hybrid" battery to run a 55l Lemack fridge. It worked like a charm until the regulator on my Hilux shook to pieces on the Cordillo Downs road to Birdsville (along with two tyres). The battery got very flat and I never got it fully charged again until I got home and used a battery charger.

The next year we camped for two weeks in the same place and apart from an occasional trip into the pub, there wasn't much charging going on. We ended up having a generator running for most of the day. Thankfully it was cold at night so the fridge didn't need to run more than once or twice.

The next year, after reading Collyn Rivers' book "Solar That Really Works! Motorhome Edition", I was convinced that this was probably the best (although very expensive) long term solution. I bought two 80 watt panels, a plasmatronics regulator and shunt, and a Century 75Ah deep cycle Battery. This worked very well except for a couple of very overcast days and warm nights which kept the fridge running every hour on the hour. Once the sun returned the battery charged up nicely.

I don't expect to have any problems this year because I have just bought two AT121000d 100Ah AGM Amptech batteries to use with my solar panels. I am assured that they are AGM batteries although the word "AGM" doesn't appear anywhere on the batteries.

I would be interested to hear if anyone else has these batteries and how well they work.

Marc 1
Need to get out more
Posts: 2461
Joined: January 25th, 2007, 11:58 pm

Unread post by Marc 1 » April 28th, 2007, 12:15 am

Richo1951 wrote:
The next year, after reading Collyn Rivers' book "Solar That Really Works! Motorhome Edition", I was convinced that this was probably the best (although very expensive) long term solution. I bought two 80 watt panels, a plasmatronics regulator and shunt, and a Century 75Ah deep cycle Battery. This worked very well except for a couple of very overcast days and warm nights which kept the fridge running every hour on the hour. Once the sun returned the battery charged up nicely.

Great to see someone with a correctly sized system and who has done the necessary research to do it. Solar panels do produce bugger all on heavily overcast days, that is why the battery needs to be sized to give a couple of days reserve capacity. On a bright sunny day your regulator should be showing what time your batteries reached float (FTIM on the display) and if the system is sized well it should be no later than about 2pm. That essentially means the battery is full after about 5 or 6 hours of sun which allows those extra hours of sun to go toward restoring the extra Amphours used when the panels got no sun on the cloudy days.

AGM batteries seem to be really fashionable at the moment, and they are usually a quality product with a fairly hefty price tag. If you need to put a battery inside the cabin of a vehicle, then some form of Valve Regulated Lead Acid (VRLA) battery is the go. VRLA's can be gell cells or AGM's - AGM's have very low internal resistance copared to other deep cycle batteries, so they can be charged and discharged at much higher currents without sustaining damage. Put too many amps through an ordinary deep cycle, and they can overheat, plates can warp and you'll get failure. VRLA batteries are more temerature sensitive as a rule, some are not designed for the vibration of a vehicle, and they can have narrower or more specific charging regimes to maximise their lives. Remember if they get too hot through overcharging or being next to a hot turbo they will gas off through the one way valve (hense VRLA). The loss of this moisture is permanent and as the plates inside the battery dry out, the battery loses capacity and will eventually die.

I still believe the smartest deep cycle units are good quality flooded cell units. Unless you have rapid charging issues, or are keeping a battery in the cab, they provide the best bang for the buck. If they are overcharged they'll just boil off some of the electrolyte (easily topped up with distilled water). They are more tolerant of different charging regimes and are more widely available. The state of the battery can be fairly accurately checked with a hygrometer too. My next battery will be a quality flooded cell unit.

l26255
Been here a while
Posts: 201
Joined: December 19th, 2006, 9:57 am

Unread post by l26255 » April 28th, 2007, 7:29 am

Marc i agree , also i always recommend 3 days storage (battery capacity) 1.25 to 1.5 times usage as a rule for replacement(charging) the rule of thumb calculation i use USAGE STORAGE REPLACEMENT ( 3 x usage for storage 1.25-1.5 x usage for replacement) also keep in mind that certain battery types have certain cycle life although unless in a constant use situation this really doesnt present a great issue for the majority of people because a well maintained battery will supply years of good service.

Richo1951
Getting to know the place
Posts: 13
Joined: April 27th, 2007, 10:29 pm
Location: Mount Gambier

AGM Batteries

Unread post by Richo1951 » April 28th, 2007, 8:33 pm

I would prefer a conventional deep cycle battery but I am limited to where I can place it. I had it stored in a ventilated under-tray toolbox but getting at it to check the water, s.g.'s etc was too hard and besides I only had room for one. The AGM's are stored in a ventilated container on the tray, inside the canopy. I wasn't game to put the deep cycle battery there.

One good thing about the coventional deep cycle was that it was the default setting for the PL20 regulator. Getting the right settings for the Amptech AT121000D AGM batteries is difficult. I haven't been able to get any specs from the supplier or the internet.

Bazza_rips
Part of the furniture
Posts: 1488
Joined: October 29th, 2006, 8:39 pm
Location: Capelle Larba, Brisvegas

Unread post by Bazza_rips » April 29th, 2007, 7:47 am

I ended up with a fullriver 120 amphour battery. kicks arse. see the install here ----> http://www.4wdmonthly.com.au/forum/show ... hp?t=29405
Moderate amount of kit......... Still a bloody long list to go!

Who needs Bling when you've got Black sunnies?

Return to “General Tech”