We have a 2003 Newmar 3803 diesel motorhome. We keep the unit at our home plugged into 50 Amp shore power.
While plugged in to shore power, the house batteries constantly charge and the battery display panel shows a bulk or float charge keeping them around 13.5 V.
However, each time we go back to crank the unit (we try to crank it about once per week), the chassis batteries are dead…usually reading around 12V which is not large enough to crank either the engine or generator. The most recent time, the voltage was so low the generator wouldn’t even make any cranking noise.
When plugged into shore power, the house batteries read around 13.5V but the chassis batteries read around 12.5V after running the coach for about 30 minutes. I was told that both house and chassis batteries should charge when plugged into shore power, but that is not the case.
I understand the small solar panel on the roof is independent of the BIRD and wired only to chassis batteries but isn’t enough to keep them charged, only to slow the parasitic discharge.
The batteries are 12V DEKA brand with around 1000 CCA each replaced within the past year.
What could be the cause of my chassis batteries going dead (below 12V when we need around 14V for cranking).
While plugged in to shore power, the house batteries constantly charge and the battery display panel shows a bulk or float charge keeping them around 13.5 V.
However, each time we go back to crank the unit (we try to crank it about once per week), the chassis batteries are dead…usually reading around 12V which is not large enough to crank either the engine or generator. The most recent time, the voltage was so low the generator wouldn’t even make any cranking noise.
When plugged into shore power, the house batteries read around 13.5V but the chassis batteries read around 12.5V after running the coach for about 30 minutes. I was told that both house and chassis batteries should charge when plugged into shore power, but that is not the case.
I understand the small solar panel on the roof is independent of the BIRD and wired only to chassis batteries but isn’t enough to keep them charged, only to slow the parasitic discharge.
The batteries are 12V DEKA brand with around 1000 CCA each replaced within the past year.
What could be the cause of my chassis batteries going dead (below 12V when we need around 14V for cranking).
