Magnum auto generator start/Batteries Dying

[Lmm]

I am dropping 1 volt on chassis batteries while disconnected from shore power in 1 day. The only thing that is noticeable is green ready light on this magnum device. I am sure there are many phantom drains, but this device remains lite while Rv switch is off. Can I disconnect this device by unplugging without causing other problems? My chassis batteries have always lost power while storing. All batteries are new and in good shape. 2018 Thor 31 freedom.

[16ACE27]

define "drop one volt.

Dropping from 13.6 VDC to 12.6 VDC is just removing the surface charge.

Dropping from 12.6 VDC to 11.6 VDC is going from 100% to 20% - quite a large non-use drop in one day.

[Lmm]

Voltage went from 12.7 to 11.7. Thanks

[Lmm]

My batteries aren’t reaching over 13 volts from shore power, I must have another issue

[16ACE27]

Originally Posted by Lmm

My batteries aren’t reaching over 13 volts from shore power, I must have another issue

The battery voltage applied when charging from the converter (or alternator) will go from 14.5 VDC (bulk charging), to 13.6 VDC (absorption charging) to about 13.1 VDC (float charging). Once the charge is removed a good battery will return to its fully charge voltage of 12.6 VDC to 12.8 VDC after an hour of so. IF your batteries are being fully charged (which takes hours, 4 to 6 depending on the State of Charge (SOC) when beginning the charge cycle, and they are dropping to 11.7 VDC in a day, then you have a significant draw on the batteries or their capacity has been diminished.

[EA37TS]

4 to 5 year old batteries may be on their last leg. Might be time to have them tested and replaced.

[Lmm]

Batteries are 7 months old. It’s poring rain today, I’ll continue tomorrow.

[The Gritz Carlton]

Originally Posted by Lmm

Batteries are 7 months old. It’s poring rain today, I’ll continue tomorrow.

Excellent tool for battery testing. Even though they are only 7 months old, you could have one battery dying. A bad battery in a set will pull the other one down with it. This tool is fool-proof. Charge both batteries to full SOC and follow the 10 second test instructions. It will eliminate batteries as the culprit up front. I disconnect all cables from the batteries before testing as it isolates the test to just that battery.



https://www.amazon.com/OTC-3181-Heav.../dp/B000O3U2UQ

[Lmm]

I have a load tester. Great idea, I will check tomorrow as today it is raining.