Community Forums

Bvandamme · 10-16-2022, 12:23 PM

We have a 21 Tiffin allegro with the residential fridge. I am charging my batteries before we go to bed but by morning they are almost dead. We have 4 6v setup. Wondering if going to the new lithium battery is the way to go.

Old-Biscuit · 10-16-2022, 12:32 PM

How old are your batteries?

How do you know they are fully charged?

How much amperage does your fridge draw?

Marine359 · 10-16-2022, 12:58 PM

You should not need to go to LiFePo4 to get through the night. If your Allegro came with the 4x 6v setup and the residential fridge, I’m sure the Tiffin people would not let one go out the door that couldn’t get through the night. The OEM battery setup (over 400 amphrs) should be plenty for the coach. Check charging amperage, and battery voltage. If they seem ok, check fluid and load test. Presumably the fridge has a dedicated inverter. You should be able to test its output amperage while the fridge is running with a loop multimeter. Your BIM should tell you how many amps are going from charger to batteries.

twinboat · 10-16-2022, 01:36 PM

If your using all of you capacity overnight, changing to lithium won't change that.

More capacity of any type of battery will, but that's not your problem.

Are you running the generator twice a day or just at night ?

2 hours in the AM and 2 to 3 before bed should keep your batteries happy, unless the batteries are failing.

If your running an ice maker, switch that off, the suck power.

jacwjames · 10-16-2022, 01:51 PM

My ~9 year old batteries finally had to be replace last year. Replace with 4 of these from Sams Club https://www.samsclub.com/p/duracell-...plp_product_17

I can easily go 8 hours depleting the battery from 100% to ~75%.

Something must be going on, is there anything else on that would use a lot of amps?

At minimum I'd check your batteries electrolyte level and check with hydrometer to make sure each cell is good.

Do a controlled test. Charge the batteries to 100%, unplug, and monitor battery level and see what it is after 8 hours.

twinboat · 10-16-2022, 02:41 PM

A real controlled test is draw 5 amps per 100AH and see if it lasts 20 hours before 10.6 volts is hit.

That's how AHs are rated at the 20 hour rate.

computerguy · 10-16-2022, 07:25 PM

That was generally my experience on ‘16 Bounder. It has the Samsung residential fridge. On my rv there is a 6 amp parasitic draw without the fridge. With the fridge running on the inverter ( no shore power or solar) I run 20-30 amps. The Samsung cycles on and off in 30-40 minute cycles. I think that is the compressor. Then at some point for 10-20 mins the defrost cycle kicks in and draws another 40 amps I believe.
Why I went to 600 ah of lithium. Lead acid should not be run down more than 50% if you want to get any sort of life span out of them.

Jkwilson1989 · 10-17-2022, 06:01 AM

When you say you are “charging my batteries before we go to bed” are you running the generator for several hours? If batteries are low, it takes some time to charge them. You’ll pretty quickly get the indicator to say they are charged, but that’s surface charge and not valid info.