Coach battery not holding charge

was_butnotnow wrote:

Will look into getting a more powerful trickle charger for the coach batteries.

NO, NO, NO. The battery associated with the truck chassis upon which the RV was built should NOT lose any charge when the truck is turned OFF. Just like any other vehicle.

Once that battery is fully charged, it should sit there for MONTHS with little or no loss of charge.

Your story is confusing but it is entirely possible that your truck chassis batteries are not being charged EVER AT ALL even when the engine is running and you need to get the alternator fixed.

You should STOP SPENDING MONEY ON SOMETHING THAT YOU APPARENTLY DON'T UNDERSTAND.

was_butnotnow wrote:
I know there is no charging of coach batteries from charger/inverter or shore power only when engine running. But do have that 2 A charge from the solar controller to the coach batteries.
By the way, they are new.
I can start the MH with the power boost turned on and charge the coach batteries up but then they don't hold that charge.
Will look into getting a more powerful trickle charger for the coach batteries. Anyone recommend a good full-time coach charger that I can run off of my house batteries or inverter. The inverter is always on when not on shore power do to a residential fridge.

You KEEP saying COACH Batteries. STOP! You are talking about the CHASSIS Batteries. Chassis are the ENGINE Batteries. COACH are the RV Batteries. Doug

My “in storage” solar panel puts out 1.4 AHs at high noon and keeps my batteries full. Something is drawing current.

I just ordered Amp-L-Start

was_butnotnow wrote:
I know there is no charging of coach batteries from charger/inverter or shore power only when engine running. But do have that 2 A charge from the solar controller to the coach batteries.
By the way, they are new.
I can start the MH with the power boost turned on and charge the coach batteries up but then they don't hold that charge.
Will look into getting a more powerful trickle charger for the coach batteries. Anyone recommend a good full-time coach charger that I can run off of my house batteries or inverter. The inverter is always on when not on shore power do to a residential fridge.

Well,
You don't say how long it takes, from the time you shut down your engine, with a fully charged set of CHASSIS batteries, to drop to your lower voltage of 8 or so volts. Hours, minutes, what? The shorter the time frame, the stronger the short or draw there is on them. If it takes DAYS, well then, trying to find the culprit may be a bit harder. But, to simply provide a LARGER CHARGER to try and over power the draw, is not the answer here.

As has been suggested, get out your trusty volt ohm meter and start testing where tests are needed and results can be found. Once the culprit is found, your need for a LARGER battery charger will be greatly diminished. Will your CHASSIS batteries still need a charge while on shore power, sure they will but, only enough charge to overcome the parasitic draws that are standard in many of our coaches.

And that means, pickup either a Trik-L-Start or, it's bigger brother (recommended), the Amp-L-Start. The Trik-L-Start allows a maximum of 5 amps to be diverted to the chassis batteries if and when needed. The Amp-L-Start will allow a maximum of 15 amps to be routed to the chassis batteries, if and when needed. Even though I recommend the larger or, more amperage unit, it is not because of trying to overcome a potential high amp draw, it's because I'm one of those types that, if the 5A unit works, the 15A unit will work just that much better.

If you're not aware of how either one works, it's simple, whichever one you might choose, it ties into both sets of batteries and, when the CHASSIS batteries become even .5V lower than the HOUSE batteries, then which other one you chose, will jump into action and divert SOME of the amperage intended for the HOUSE batteries, and send it to the CHASSIS batteries. This is the most logical choice for these type situations. By the way, the Trik-L-Start or the other ones, is only powered up when shore power is connected and, your inverter/charger is charging the HOUSE batteries.
Scott

Hi,

You could use either an Amp-L-Start or possibly a Trik-L-Start.

However, I think I'd want to know what was drawing so much power.

I know there is no charging of coach batteries from charger/inverter or shore power only when engine running. But do have that 2 A charge from the solar controller to the coach batteries.
By the way, they are new.
I can start the MH with the power boost turned on and charge the coach batteries up but then they don't hold that charge.
Will look into getting a more powerful trickle charger for the coach batteries. Anyone recommend a good full-time coach charger that I can run off of my house batteries or inverter. The inverter is always on when not on shore power do to a residential fridge.

Instead of "shooting in the dark", spend a few bucks and get yourself a digital multi meter with an amp clamp. Many to choose from on Amazon, such as Uni-T UT210E.

When searching for electric current "leakage" (Where is the power going ?), the othe method is to use your volt meter and probes to check the voltage drop across each fuse. All plug in fuses have 2 little spots on top. Just touch each spot with a probe. Ideally it should be ZERO if everything on thar circuit is turned off.

was_butnotnow wrote:

But even with the battery switch OFF they won't hold a charge. Goes to like 8 V
Should the 2 A charger keep the new coach batteries charged?

Your battery switch should be OFF ONLY when the RV is stored and not used. If the solar will be active during storage, the switch probably NEVER needs to be OFF.

If the batteries are going below 8 volts, you aren't using something right. Except in some kind of emergency situation they never should go below 10.

And yes the solar controller should KEEP the batteries charged at the 2 amp setting, when in storage, but it might not recover them from a deep discharge. It is also possible that it won't keep up with your "normal" use when occupied.

Since you are "hosting" aren't you plugged into shore power all the time ? If so, the solar is kind of redundant.

was_butnotnow wrote:
The coach batteries are the chassis batteries. My thought is if the kill switch is turned off no power should be used for anything on the chassis. The 4 new AGM house batteries are charged by a solar controller 600 W solar and Magnum 2000 w PSW charger/inverter. We are plugged into 50 A as a camp host site.
We do have a cell phone charging off the 12 v dash cig plug in and wondering why that works when the kill switch is shut down that controls the chassis power.

OK, now you have learned to call Chassis batteries what they are. They are not called Coach or house batteries. WHICH battery disconnect are you talking about and where is the disconnect located? Usually on most Brands of Motorhomes, the Dash charging ports are controlled by the Coach batteries because they realize that people will want to use them for their phones and such while camping. HOW long does it take for the chassis batteries to go to 8 volts? Usually on Monaco products if you turn the MANUAL battery switch OFF at the rear, that kills the chassis batteries. If you are just turning the entry door battery disconnect OFF that only kills the Coach batteries and it should NOT be OFF when using the RV. Doug