Dead battery and failing generator - brand new, 2 day old fifth wheel!

[newmanmeg]

My husband and I have a brand new Grand Design Momemtum 385th, toy hauler. We are boondocking for up to a month and are being very conservative with everything (power, gas, water) to get us through to the end.

Yesterday was our first day in the 5th wheel and we turned the generator on to watch a bit of the Olympics and charge the battery. We were told about 30 minutes of the generator should keep the battery full.

After 20 minutes the generator sputtered and died. It turned over and came back on in the morning. We had the generator on about 1.5-2 hours spread throughout the morning.

All today we kept battery usage to a minimum. The propane fridge was on, listened to the radio, used the water pump briefly, had the kitchen dome fan on. No lights. We left for errands and came home to the fridge beeping that power was low, sure enough 1 battery bar! It was full yesterday when we left the dealer.

The generator would not turn on. Jumped the battery from the car, which gave the battery a bit more juice, but still no generator.

Last week at the dealer the battery had died and they had it out for days, supposedly charging it. Faulty battery? Why wont the generator start when the battery is jumped? Why won't it charge the battery?

[Oakman]

Welcome to the Forest River Forum. I’m not familiar with you RV so I can’t help much. I can tell you that your Momentum by Grand Design isn’t part of the Forest River family of RVs. If you Google Grand Design Owners you will find a forum dedicated to the Grand Design RV with owners that are more familiar with your rig. Hopefully they will be able to help you with your problem and any future issues.

[TURBS]

30 minutes will never charge a low or down battery properly.
Whomever told you that is a fool.


TURBS

Goshen is my playground.
The last man standing also has a sharpie

[Herk7769]

Search here for information on deep cycle batteries. (The FAQ section has some great info too)

Deep Cycle batteries need upwards of 36 hours to fill completely when dead using a multistage charger. Your generator can only replace about 50% of capacity running in a normal 6 hour period. (4 hours of fast (bulk) charge and 2 hours of absorption)

[garbonz]

Originally Posted by f1100turbo

30 minutes will never charge a low or down battery properly.
Whomever told you that is a fool.


TURBS

Goshen is my playground.
The last man standing also has a sharpie

YEP X2. Think about it. 30 minutes of charging with say a 45 amp charger, even if it was putting a full 45 amps out would be 22 amphours total. If you have only 1 battery that is 80 amphours, that would be grossly inadequate.

In all honesty, boondockers need to get very smart about all aspects of power use and charging and be equipped with knowledge about their power use, battery size, charger performance to do it right.

Time to do a little research on your rig and quit listening to dealers.

[KMP44]

I would also be after the dealer for a new battery. Running a deep cycle battery completely dead reduces its performance. With brand new rig, you should have a brand new battery that wasn't run dead before you picked it up.

[Herk7769]

Originally Posted by garbonz

YEP X2. Think about it. 30 minutes of charging with say a 45 amp charger, even if it was putting a full 45 amps out would be 22 amphours total. If you have only 1 battery that is 80 amphours, that would be grossly inadequate.

In all honesty, boondockers need to get very smart about all aspects of power use and charging and be equipped with knowledge about their power use, battery size, charger performance to do it right.

Time to do a little research on your rig and quit listening to dealers.

Even a 45 amp charger can not supply 45 amps continuously or you would boil your deep cycle battery dry.

These high rate chargers only deliver that charge to STARTING batteries and even then switch over from bulk to absorption in an hour or so.

Deep cycle batteries CAN NOT take that rate as the flat thick plates develop a surface charge quickly and the converter goes into Absorption (charging amperage drops to less than 5 amps).

Starting batteries have THIN, WAFFLED plates to increase electron delivery and absorption but have very low capacity. They charge up quickly and run down quickly; but deliver huge cranking amps for 10 or 15 minutes.

[Herk7769]

Originally Posted by KMP44

I would also be after the dealer for a new battery. Running a deep cycle battery completely dead reduces its performance. With brand new rig, you should have a brand new battery that wasn't run dead before you picked it up.

This is also true. Running a deep cycle battery much below 50% capacity will permanently reduce the maximum total capacity of the battery. It will still "charge up" but never again last as long as it was when new.

This graph shows the impact of discharge percentage at charge time, to longevity. The deeper the discharge, the shorter the battery life.

[garbonz]

That why I said "even if the charger could put out 45 amps".

Good argument for AGM and Gel's tho. since they can take a much higher rate of charge than flooded deep cycle. AND another good argument for solar panels.

Good argument for a large battery bank also that you can keep between 80% and 50% SOC. and be recharged that much in an hour or so.

Good argument for research into ALL these aspects of power use and replacement.