Jayco RV Owners Forum

Thread Tools Display Modes
Old 10-17-2017, 05:59 PM   #1
Senior Member
Mustang65's Avatar
Join Date: Nov 2012
Location: Clearwater, FL area
Posts: 3,643
Battery Talk - What is "Charge Cycle"

Everyday we hear that we should only discharge our batteries to 12.0Volts, known as the 50% rule, and you follow that rule to a "T". Then you look at the manufactures "Life Cycle Chart" for your battery, it says you should get about 1500 cycles using the 50% rule, with proper maintenance. Well, how long is 1500 cycles? Do you count the times that your battery is recharged? Once a day?

Good Question!!

The actual definition of a "Cycle" is the "Charge Cycle", so does that mean that if I bring my battery down to 50% that is one charge cycle? Actually, "NO"!! In the battery industry the guide lines for a charge cycle is the actual discharging of the battery till there is no power left in it, or 10.5 Volts (SG=0). 100% discharged!! But wait, you only discharge the battery 50%... what gives here.

Well, lets say you have a 100 Ah battery and on Monday you end the day only using 50% (then recharged to 100%), Tuesday 20% (then recharged to 100%), Wednesday 15% (then recharged to 100%), Thursday 15% (then recharged to 100%)...... Now you have your 100% discharge. So, 1500 cycles could take a long time. Oh, but wait don't forget to add "The AGING PROCESS" into the equation, some numbers for that are 10% a year and increasing as the battery ages... so your batteries Ah's at 100% charge are not going to be the 100Ah any more. IE: My 5 year old Interstate 85Ah batteries are at 40Ah now (fully charged), test results can be found in the RVing with SOLAR Social Group, under a post "The Numbers are In". Still darn good batteries and just like us aging we are not as strong as we used to be when we were younger. Still looking for a way to recharge my self again.

So "Number of Cycles"?
"In general, number of cycles for a rechargeable battery indicates how many times it can undergo the process of complete charging and discharging until failure or it starting to lose capacity"

The same holds true for any battery type, the numbers just change.


My Registry

RVing with SOLAR

2013 Jayco Eagle 284BHS
250Watt Grape Solar Panel, MorningStar MPPT 60 Charge Controller
1500 Watt Ramsond PSI, 2 Trojan T145 Batteries (260Ah)
2 - AirSight Wireless IP Cameras (used as rear view cameras)
EnGenius WI-FI extender, D-Link wireless (n) modem
MagicJack Internet Phone
2012 Ford F150XLT, EcoBoost w/3.73
157" Wheel base, HD Towing Package

Our Solar Album https://www.jaycoowners.com/album.php?albumid=329
Mustang65 is offline   Reply With Quote
Old 10-18-2017, 06:30 AM   #2
Senior Member
Join Date: Apr 2017
Location: livingston
Posts: 579
Well, kinda. The 1500 rule is just a guideline, not hard and fast.

It does depend on how the battery was treated. In the old days of simple chargers there were many cases of abused batteries, overcharging, undercharging, etc. Now days most people have chargers designed by the battery folks that will do the "3 stage" charge and will properly do a 'maintenance' charge. Most also have a 'reconditioning' charge to help revive a battery.

Then there are environmental conditions. Extreme cold or hot weather will affect the life of the battery as well.

Last is the manufacturing. Some batteries just last longer than others, and is not necessarily related to the price or mfg advertising.

I've had batteries last for 5 or 6 years and others that only went 2 years, with the same relative usage.

2017 Eagle HT 29.5BHOK
2009 Dodge 2500 Cummins, Crew, 4x4
Maggie, Old English Sheepdog
vcbice is offline   Reply With Quote
Old 10-18-2017, 03:06 PM   #3
Senior Member
Join Date: Jul 2014
Posts: 333
Every time you discharge a 12v battery down to zero, you shorten the life of the battery. In some cases, a battery that is discharged 100% will not accept a charge, why do you think the battery manufacturers define the "cycle" the way they do?
'08 Greyhawk 31SS
jimp is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Virginia State Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -6. The time now is 04:15 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2002-2016 Social Knowledge, LLC All Rights Reserved.