AGM Battery Charging

Hi Tim thanks for the details between you and Deano I have a lot of info to digest. I want to get this right as future camping will be long periods and off the beaten track with a compressor fridge.
Is there any way that a laymen can test the amount of charge in an AGM battery, I currently use the voltage as my indicator when the fridge is drawing power.:confused:
Peter.

PS Thanks to Dave and all who are responsible for this forum enabling us Landy owners who like to do their own work and modifications an avenue of expert help. Many thanks:)

My understanding is that you need to disconnect any load or charging and let the battery sit for a bit then check the voltage.
If its under load you're not going to get a valid reading. As an extreme example - your battery might be full charged but if you crank the engine the voltage could come down to 10v or so (which is lower than a completely discharged battery if you look at the SOC charts).

Steve

Quote:

---

Originally Posted by pjlhat

Hi Tim thanks for the details between you and Deano I have a lot of info to digest. I want to get this right as future camping will be long periods and off the beaten track with a compressor fridge.
Is there any way that a laymen can test the amount of charge in an AGM battery, I currently use the voltage as my indicator when the fridge is drawing power.:confused:
Peter.

PS Thanks to Dave and all who are responsible for this forum enabling us Landy owners who like to do their own work and modifications an avenue of expert help. Many thanks:)

---

I have two ways to test mine.
1. I bought a plug from Jaycar which plugs into a cigarette lighter and reads the voltage. So it is reading whatever the current is flowing through the electrical system. If the engine is running it will read what the alternator is putting out. If the engine is stopped it is reading the battery. When I start the vehicle I can watch the reading go up as the alternator kicks in, usually to sit around 13 volts.
I can plug it into my camper and read the camper's battery. Only cost about $20. Very useful.
2. If I attach my multi-stage battery charger it first gives a reading of the state of the battery, before beginning to charge it.

Quote:

---

Originally Posted by drivesafe

Hi Mick and Yes.

Agms are lead acid batteries, as are Gel batteries.

BTW you can mix any type of lead acid battery ( Wet, AGM or Gel ) with any other type and solar regulators and alternators, charging the same battery or batteries, will have no problems fully charging them.

---

Yes, I've used my 80 watt solar panels with the regulator on both wet cell deep cycle and AGM batteries and it all worked fine. In sunny weather the battery is usually fully recharged by mid-morning after running down a bit during the night. Then it just stays charged while there is sunlight.

Hi pjihat and as per our phone conversation, here is the Loaded Voltage Chart.

https://www.aulro.com/afvb/images/im...016/06/640.jpg

Quote:

---

Originally Posted by steveG

My understanding is that you need to disconnect any load or charging and let the battery sit for a bit then check the voltage.
If its under load you're not going to get a valid reading. As an extreme example - your battery might be full charged but if you crank the engine the voltage could come down to 10v or so (which is lower than a completely discharged battery if you look at the SOC charts).

Steve

---

Hi steveG, there is a lot to this subject and the link below will give you a bit more insight to SoC and battery capacity.

http://www.aulro.com/afvb/technical-...-charge-2.html

Quote:

---

Originally Posted by drivesafe

Hi pjihat and as per our phone conversation, here is the Loaded Voltage Chart.

https://www.aulro.com/afvb/images/im...016/06/640.jpg

---

Yes, I read somewhere that a cell is typically 2.1 so 6 x 2.1 is 12.6. Probably varies I guess.

Hi Deano, Thanks for all the time and details:) I have digested it now plus a few yarns with Tim and now ready to revamp my set up.:)
I have decided to go with Tims Diagrame on post 4 with the SC80 plus built in 50 amp circuit breaker. Have ordered it and just waiting for it to arrive. All other gear I can sorce locally. With regard to the fixed solar panels on the roof are yours fixed or are you able to slope them to suit your camp position. Would be interested in a method of tilting them so one can still get the best of positions view and weather wise.:angel: The other thing is would it be practical to have one large regulator that could handle both the roof mounted panels and the fold up panel. With the regulaor mounted in the Trayon and accessed by two external sockets. If so the question is then what size regulator. Looked at one on ebay 30A solar panel control regulator 12v 24v Auto 360w/720w for LED light. Is that some thing that would suit:confused:
Peter.


[QUOTE=DeanoH;2324316]Hi Peter, We have a similar setup to you on our OKA. ie. two roof mounted solar panels and a separate vehicle battery(s) and two house batterys. I had a portable fold up panel of 140
You mention that your portable panels "appear to have a built in regulator", which is a bit of a worry. From my experience the stuck on the back regulators are usually of very low quality, indeed if you have one.
Whilst I'm merrily spending your money :D:angel:, why not buy two regulators the same ? one for the roof mounted 160 watt and one for the 120 watt portable panels. This way you would be able to fault find/swap if need be as long as both regs were both rated at a min of 160 watts.
The portable panels reg could be left mounted in/on the camper with a suitable plug to connect the panel directly to it. For good results it is best to have the portable panels solar reg as close to the house battery as possible.