6V Deep Cycle Batteries

Unless you used a smart charger, like a charge wizard module plugged into your dumb charger, you have shortened the life of your batts. The smart charger maintains the battery and stirs it as well as keep it charged up. In addition you need to check the fluids regularly and not let the batts go more than 50% discharge. Go to a service station and have each batt tested. You might have just one with a dying cell that needs to be replaced. My Trojan T125's were 10 years old when I sold them and still going. So on my new to me TT I bought the sames ones and bought the charge wizard module for $25 its worth its weight in gold.

2oldman wrote:

Ivylog wrote:
A hydrometer will answer your question better than we can.

Yeah.

yeah yeah..

I'm in Modesto on biz for 2 days. Too bad I don't have my amp clamp..

Desert Captain wrote:
It sounds like you may have a bad cell, perhaps more than one. If so they are toast, they will take a charge but will not hold it for long especially with any kind of load on them. Get a Hydrometer and test each cell. What you should see is that each cell in a battery reads approximately the same. If one is significantly lower than the others it is bad and the battery is history. If that is the case you will want to replace both batteries.

:C

My thought too. Typically, your system will stay in absorb, never go to float. After as much of a charge as you can get, let the batteries "rest" for an hour (preferably disconnected)

Then take the caps off. For each battery, put the neg terminal of your meter on the neg post, and the positive in the electrolyte of each cell in turn. Meter should step up about 1.6 volts each cell as you run down the battery.

Your dead cell will be easy to spot.

My Gel 8D battery setup has 4 of these batteries, when the voltage drops to 12.2 VDC, the genset auto starts, runs 3.25 hrs, holding batteries at 14.2 VDC FOR ABOUT 45 min. In fall, winter normal run time is very easy 2 days with household Samsung 24.5 cf frig, (auto defrost off) normal Directv, 32" Samsung LED, very little microwave use.
Dave M

How many years.. 7-10
How long did you hold them at 13.6 before turning off the generator

With a good 3-stage charger you can take them from 1/2 full (11 is less than that) to 90 percent in about 2-3 hours, it will take at least that many more to FULLY charge the batteries

Side note: Lifeline AGM takes the bulk charger faster,, (If you have a really big converter that is) you can do the bulk (first step) in half the time.. But look at the six hour total, that's not much improvement.

Ivylog wrote:
A hydrometer will answer your question better than we can.

Yeah.

fridge ?
3way ?
on propane or ON 12vdc
12vdc is a "travel mode", engine running
12vdc sucks the battery down with a 20amp/245w power drain

if the fridge is on the inverter using 120vac (automatic mode) it will use 300+ watts or about 25amps...even more power drain than 12vdc mode

fridge should always be on Manual mode propane , unless on shore power
even then i prefer LP/propane

A hydrometer will answer your question better than we can.

It sounds like you may have a bad cell, perhaps more than one. If so they are toast, they will take a charge but will not hold it for long especially with any kind of load on them. Get a Hydrometer and test each cell. What you should see is that each cell in a battery reads approximately the same. If one is significantly lower than the others it is bad and the battery is history. If that is the case you will want to replace both batteries.

:C

They may need replacing, but before that is done I would put them on a good "portable smart charger". They may not be getting a full complete charge through your coach charging system & may benefit from an "equalization" charge which can only be accomplished with a Smart charger. Equalization charges at a range of 15 - 16 volts & is required occasionally for lead acid deep cycle batteries.

Even if the batteries turn out to be bad & you have to buy a "smart charger" to do this, the charger & information below can be beneficial for the future.

Here is a link concerning deep cycle battery maintenance:

The 12volt Side of Life (Part 1)
www.marxrv.com/12volt/12volt.htm