Drained Batteries - Troubleshooting Tips?

[Islandsmith]

I parked our rig a month ago after our last weekend away. I really thought I had turned everything off and flipped the Use/Store switch before leaving it but today when I went out there it was completely dead. I mean DEAD...no coach or chassis power. In the past I've left things for months without any issues as long as the store/use switch is set.

It got too dark before I could investigate but figured I'd ask the brain-trust here as I need to get things figured out before we leave this weekend.

If something in the coach was left on isn't the BIM designed to avoid complete discharge of all batteries? I have The Precision Circuits BIM 160 in my rig. I was sort of surprised that both the Coach and Chassis batteries were drained.

I've got a battery charger set up overnight and will look things over tomorrow to see what might have been left on.

Any brilliant ideas on where to look? I will be doing some research on how to test for parasitic draw I supposed.

[Bob Denman]

Parasitic drains can easily drain batteries in a Month.
You have to physically disconnect them.
I used a pair of bayonet switches on the ground leads...

https://www.thorforums.com/forums/at...1&d=1608125410

[10scDust]

Are you parked near 110vac outlet?
On ours I ran connector leads for a battery tender from the coach batteries to the engine compartment, then another set of leads from the chassis battery.
During these cold long term storage times, I tuck the extension cord under the hood, and with a multiplier plug I connect two battery tenders connected to each lead during my winterizing period.
During summer months, when not traveling, I have an RV outlet at my home parking spot, this way I leave the a/c & fridge on so I don't cook the inside of the rig with the power cord to RV plugged in, this way the converter maintains the batteries.
I don't worry too much if there's a parasitic draw.
It could be the CO2 alarms, or radio, but I think they are de-powered when use switch is turned off.
Just a consideration for you to ease the worry....
Meanwhile, a car port roof is on order, 40 foot long x 13 foot tall, in case I up grade from this 30 footer!

[Beau388]

Originally Posted by Islandsmith

I parked our rig a month ago after our last weekend away. I really thought I had turned everything off and flipped the Use/Store switch before leaving it but today when I went out there it was completely dead. I mean DEAD...no coach or chassis power. In the past I've left things for months without any issues as long as the store/use switch is set.

It got too dark before I could investigate but figured I'd ask the brain-trust here as I need to get things figured out before we leave this weekend.

If something in the coach was left on isn't the BIM designed to avoid complete discharge of all batteries? I have The Precision Circuits BIM 160 in my rig. I was sort of surprised that both the Coach and Chassis batteries were drained.

I've got a battery charger set up overnight and will look things over tomorrow to see what might have been left on.

Any brilliant ideas on where to look? I will be doing some research on how to test for parasitic draw I supposed.

All coaches have some parasitic draw on both sets of batteries. For the chassis battery, it is the radio memories and engine/transmission computers. For the house batteries, it is usually safety devices and a miss-wired inverter. Flooded batteries will loose 0.5% to 0.8% of their capability per day due to self-discharge; thus, after two months they are basically dead even if there is no parasitic draw. One of the great advantages of AGM VRLA batteries is their low self discharge rate which is typically 1% per month. Anyone that owns a classic or collectable car knows they must be driven at least monthly or prepared for long term storage. Vehicles deteriorate much faster when improperly stored as compared to those driven monthly.

[Coastal Waters]

Do not flip the storage/use switch into storage mode if you are connected to a power line. The batteries will not charge. Check your owners manual to confirm my advice is correct.