Short battery life. Kirkland battery quality or system?

Bikersmurf

Expedition Leader
On average I'm replacing all 4 batteries at just over 1 year. Need some extra brain power to help solve this.

Batteries:
4 - 850 CCA Kirkland starting batteries

Charging:
215 A Mitsubishi Alternator (<1000 hrs) works 100%
Head 60 max 40 cont amp 13.8v shore charger

Loads:
5a fridge on house batteries
7.3 Diesel
E350 Ambulance

Isolator:
Now ACR... was Vanier diode isolator with VR getting input post isolator from Starting batteries.

Getting to the point:
1) Costco hastled me about last warranty exchange on <1 year old batteries. Stating on average I'm replacing batteries about once a year... may not honour warranty next time.
2) Getting sick of changing batteries

Pre ACR, Alternator providing 14.07 V to batteries. Shore charger rated at 13.8... actually only seeing 13.3 due to load/draw/batteries/???, but plugged in every night.

With ACR, Alternator 14.5-14.6v. Shore charger voltage seems slightly higher... likely higher starting charge level.


Now time will tell, but is there something I'm overlooking?

Any reason batteries keep dying?

Are the batteries simply not up to the job they're speced to do?

I'm also planning to setup a relay to switch the fridge from house power to shore when connected to shore, thereby reducing the load on 40(60)A Head charger. The charger is designed to charge and supply 12v at the same time, but I'm running out of ideas.

Batteries I'm guessing are sulfating... when they did, they seem to charge faster, but a 5 amp draw will kill two of them in <2hrs.

Marine batteries died equally fast, so I switched to starting batteries because they didn't seem to be able to keep up discharges of 250A+ when the inverter had a sudden load... the 215A alternator... or being backups for the starting batteries.
 

dwh

Tail-End Charlie
Shore charger voltage not nearly high enough. 13.8v is basically a float voltage. If it's not pumping the battery bank up to at least 14v+ (14.5v+ is much better), then they aren't getting fully charged.

The alternator/ACR is okay IF you drive enough hours to get the job done - but almost no one does.

Chronic undercharging leading to excessive sulfation and premature failure. Which you are making even worse by using cranking batteries instead of deep cycle.
 

calicamper

Expedition Leader
5 amp draw constantly? Whats your typical run time on the alternator? How often are you on shore power? And how long?

Solar? To help cover day time load while parked off grid?

Deep cycle marine grade is for sure better than the high amp short capacity starter battery design.

Any other possible parisitic loads?
 

Bikersmurf

Expedition Leader
I was thinking along those lines. The deep cycle batteries died just as fast, so that's why I switched... and deep cycle batteries don't like rapid charging, do they?

99% of the time the house batteries only have about a 6 amp draw for a maximum of 5 hours (which a pair of starting batteries should be able to handle 2-3 day's a week).

Any thoughts on why the starting battery bank also only last a bit over a year? I've never had starting batteries that didn't last 6-8 years before.
 
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dwh

Tail-End Charlie
I'm not familiar with "Head" brand battery chargers. Never heard of them and find nothing with a quick search.

I get the feeling you have a "13.8v power supply" (often used for radios), when what you actually need is a "multi-stage battery charger".
 

dwh

Tail-End Charlie
Any thoughts on why the starting battery bank also only last a bit over a year? I’ve never had starting batteries that didn’t last 6-8 years before.

Starting batteries are intended to supply around 1/5 of an amp*hour to start the vehicle and then be immediately recharged to 100%.

Dragging them down 25 or 30 amp*hours on a regular basis will kill them. Especially if you aren't getting them back to 100% charged ASAP.
 

Bikersmurf

Expedition Leader
5 amp draw constantly? Whats your typical run time on the alternator? How often are you on shore power? And how long?

Solar? To help cover day time load while parked off grid?

Deep cycle marine grade is for sure better than the high amp short capacity starter battery design.

Any other possible parisitic loads?

Run time 30-40 minutes on days it's used. Shore power 15+ hours on days used. Shore 24/7 when not in use.
On average used 2-3 days per week. Unplugged and not running a maximum of 5 hours.

Parasitic drains weren't a concern to the ambulance builder... that's why it lives attached to a cord when home.
 

SoCal Tom

Explorer
If it’s plugged in every night, then it can only be the charger. Constant amperage is not recommended for lead acid. Have you checked water levels?
 

calicamper

Expedition Leader
Thinking the same as Tom ^
My sailboat sits on shore power 3 stage 24/7. Two Group 31’s deep cycle nothing overly special lead acid batts

When my last charger failed the batteries were failing pretty quickly after.

Shore power charger isn’t cutting it for some reason.
 

Bikersmurf

Expedition Leader
The charger is a marine unit which was designed to float the batteries as well as cover any parasitic draws.

Water levels have always been full.

Since the amp/hours are split between two parallel batteries, the drain would only be 12-15 per battery... what's becoming clear is that the batteries aren't being brought back to up 100%. The ACR now ensures they get 14.5 V when running, which should help some.

Battery type could explain shorter House Battery life... but the Starting Bank which is only used for starting and not run down also die after 15 months. Deep Cycle batteries died just as fast but had less warranty. A pair of 110 ah batteries died in about 12 months... by the time I bought them in the warranty was gone.

I agree that the charger is the next week link and I'll address that next. It's the only thing left than can be readily changed.
 

DiploStrat

Expedition Leader
dwh nails it. Reread his posts.

N.B. Getting rid of the diode isolated got you a much better charge from your alternator, but the limitations here are driving time and the amount of charge your batteries will accept.

Solar, at least 10A, makes a tremendous difference. (5A to cover the refrigerator and background noise and then at least 5A to actually charge.)

For lead acid you want a decent multistage charger. CTEK enjoys a good reputation but there are others.

In my case, however, I simply invested in a good (Magnum Energy) inverter/charger. Two mints in one and I don't have to bother with a shore charger.
 

SoCal Tom

Explorer
Any suggestions on House Chargers... Brand, features? On a budget?

At this point we are guessing, I suggest more data. Do you have a guage like this in your system?
https://smile.amazon.com/gp/product/B013PKYILS/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Just to be clear. Are the starter batteries connected to the shore charger? If so, I would remove them. Let the alternator charge those through the ACR. The starter batteries should be starter batteries. The manual for the guest "chargepro" line seems to have seperate cables for each battery. Are yours wired that way? Or are the house batteries connected in parallel?

For chargers, I've been very happy with my progressive dynamics charger/convertor but its a single battery system. And its gets plugged in for weeks at a time. I suspect part of your issue may be that any charger is going to need 15+ hours of shore power to get them to 100%. If batteries are hooked in parallel, and they aren't matched ( and sometimes even if they are matched), they can drain each other. What happens is that if one battery has lower voltage, then the other battery "charges" it. But the act of charging raises the temp of the battery being charged, so it ends up with higher voltage, then it pushes power back to the original battery and the cycle continues. -- another question... are your batteries located close together? so they are of the same temp?


The house batteries should be deep cycle.
 

john61ct

Adventurer
Get proper quality batts designed for deep cycling.

The best battery value by far for non experts is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH pair from BatteriesPlus or Sam's Club.

Increasing quality and cost from there, none available in automotive or big box channels:

Trojan T-105s
RE variant

US Battery, Crown

Rolls at the top.

Next discussion is proper care, done right you'll get 5-7 years easy, assuming bank is sized so only rarely dip below 50%.

Get a DMM and ammeter.

Is Alternator really your main charge source?

How often do you overnight on shore power?

No solar?
 

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