Battery Load Info

[condor22]

I thought others might benefit from the information in the attached Spreadsheet re power needs. The info is relevant to my setup, but will give a guide as to what items consume.

First the setup All of the following Amp readings are real time and from the load upon my caravan battery. The battery is a 12VDC 130AH AGM. The Inverter used is a Projecta 150W pure sine wave and although it comes with a cigarette style plug, I have replaced it with a 32VDC low volt plug as that socket correctly fused is what I plug it in to.

Firstly let me say that; a fully charged AGM, just charged will hold at 13.8V for some time and not be a fair test. Equally the rechargeable items will not draw much current (Amps) if they are fully charged. So I ran my van battery down to 88% SOC (or about 16AH used). Secondly all of the rechargeable items listed in the Spreadsheet were all in need of charging and where necessary left to run to discharge them. The van battery was at 12.7V @ 14C (I would prefer to have it at about 20C but hey, its Winter). The 240VAC van charger and the solar panels were both turned off as was the battery from the rest of the van systems.

 

[condor22]

Of note

1. The left hand column are primarily van systems such as Lights, Pump, Fans and normally used Appliances and are run on 12VDC all of the time. From the van battery when Bush Camping, or via a Transformer driven from Mains or Generator, but still at 12VDC.

2. The right hand column shows various portable electrical/electronic equipment that is plugged in when needed to be recharged. With the exception of the last Info Box, these are items that only run from 240VAC.

3. The info in the right hand column marked Plug in items is split into 2 areas, 1. For 12VDC chargeable items that are run directly from the battery and 2. USB chargeable items that again charged from the van 12VDC battery via a panel mounted USB outlet at 5VDC.

4. The Far right Amps Column are the Amps those items draw when connected to a 240VAC plug, then into the Inverter and subsequently the van battery.

5. Every value the inverter needs is significantly higher than 12/5 volt direct. In fact if the direct values are totalled = 5.2A whereas the Inverter would use 14.2A to do the same thing.

6. The Laptop has no inverter value as it draws over 300W @ 240VAC and I only have a 150W inverter. (The 12VDC adaptor was purchased from Jaycar for $50.)

Conclusions

1. Use small down lights for long time use at night and the larger lights only when necessary.
2. Direct charge as much as possible from 12VDC, convert that 12VDC to 5VDC USB for those items and use an inverter sparingly.

The Antenna amp reading was negligible and a part of the total TV use.

Hope this gives you an idea of, in particular, what detector batteries, wireless etc use. How much total power is needed is variable i.e a GPX battery used for 4 hours won't take as long to charge as one used for 8 hours.

 

[Goldchaser1]

Good info condor,im loving our setup with a display panel,theres no guessing what ya using,capacity left whats coming in etc etc,real handy if ya relying on solar.....

 

[condor22]

I've posted the details elsewhere, but I consistently use about 30-35AH running the gear noted when prospecting and for the last 3 years have bush camped only.
Incl - 16 hours heating, 5 hrs TV or laptop, lights and charging all the batteries noted.

Apart from the obvious "don't use an inverter" if a 12/5VDC option is available, my main message is; "knowing what you use and charge is a key component of battery management".