The Grey Nomads Forum

75 AH battery

Stewart said
02:32 PM May 10, 2021

Hi on a rescent trip away with a non powered site my second battery box lost charge running the Waeco fridge outside, and due to torrential rain and cloudy days I had to concentrate my solar to the main caravan battery. My battery box has the replaced 100AH calcium battery in it and when charged only sits at about 12.6 volts. So I'm not sure it's that healthy. My thought are I could replace it with a 75AH which would be lighter and able to recharge quicker. Do you think this is a sensible option or is 75AH too light. It's the old problem of recharging not storage. Or maybe not use the battery box at all and leave it at home. I do have a dcdc in the van for when travelling. Cheers Stewart

Whenarewethere said
03:06 PM May 10, 2021

75Ah is perfectly ok if it can power your fridge (whatever model it is) over the timeframe you are happy with.

I have four 26Ah batteries. I started with two, then three, then four. Four Batteries suck up anything you give them.

You could have 2 batteries so they are easier to move, or a cable to the fridge.

I also made my fridge more efficient so it saves buying more AH, technically 7 days off my setup. Foam is a lot lighter than battery.

https://thegreynomads.activeboard.com/t65059593/extra-fridge-insulation-wattage-test/

Running the engine to charge up the batteries a bit is the simplest solution if you have extended inclement weather. One probably doesn't need to do this that often over a year.

PeterD said
03:30 PM May 10, 2021

Calcium batteries are capable of charging quickly if you use the correct charger voltage. What is the absorption voltage of your charger? Also if you are attempting to recharge the battery from your tugs alternator then you will not get a rapid charge unless your tug is equipped with a calcium battery.

Stewart said
04:22 PM May 10, 2021

Hi my charger at home has a calcium setting and I have seen the voltage go to 14.8. During charging. It could be ok it still shows a green indicator cell. Unfortunately the date has not been marked on the top so I'm not sure of its age. I think it's 4 years old. I use a 200 w solar blanket with pwm charger when away for the battery box. Cheers Stewart

Whenarewethere said
06:15 PM May 10, 2021

There will be a WWYY (week year, ie 2617) stamped into the case somewhere.

PeterD said
08:51 PM May 10, 2021

Stewart wrote:
I use a 200 w solar blanket with pwm charger when away for the battery box. Cheers Stewart

Does that PWM controller have a calcium setting with similar settings to the other charger? If not then get a new controller for the calcium battery. That will then make your calcium battery a better proposition than the smaller capacity one.