Short battery life. Kirkland battery quality or system?

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.

Could be due to the ACR. House batts are low, engine off...the house batts slowly suck down the engine batts till the ACR finally disconnects. Then the engine batts sit around less than fully charged.

Then maybe add not enough drive time to regularly top off all batts. That takes many hours, just pushing it up to 14.5v isn't enough - they still need hours to finish absorbing.

The good charger should fix it. It'll top off all batts through the ACR.
 

SoCal Tom

Explorer
Ahh, if its that old, then I think I would start saving for a replacement. Have you looked to see if there are any screws that might be used to adjust voltage?
 

dwh

Tail-End Charlie
ACRs if properly installed don't combine circuits unless charging voltages are present.

ACRs if properly installed don't disconnect circuits until surface charges have dissipated.

But without actually seeing the setup in person, I'm just theorizing to try and answer his question about why his cranking batteries are shot after a year. You have a better theory?
 
Last edited:

dwh

Tail-End Charlie
Have you looked to see if there are any screws that might be used to adjust voltage?

Even if there are, it won't be good. If it's a constant voltage power supply (old syle RV "converter"), then cranking up the voltage and leaving it connected all night (or days at a time) would end up overcharging the batteries - which would shorten their life...

A multi-stage charger is needed.
 

Bikersmurf

Expedition Leader
ACR is a new... less than a month. It disconnects the batteries if voltage drops below 12.85v.

The Diode isolator was part of the problem... running the batteries are now getting 14.5-14.6v at the batteries vs 14.1.

Now have a new 3 stage charger to charge batteries. The Guest unit will be retired to converter duties.

There are no screws visible on the outside of the Guest unit. If I ever have time I'll poke around inside it. The 13.1 V it's currently putting out won't charge the batteries...ever. If it could be brought up a hair to 13.8 v at low amps it would be better for absorbtion. Cooking the batteries hasn't been an issue.
 

dwh

Tail-End Charlie
Ah. Diode. Missed that.


Still, I was talking about ACR and batteries behaving normally.

Lead-acid batteries have a "surface charge" when being charged or discharged. Electrons build up on the plates and it takes time (hours) for them to fully dissipate back into the electrolyte.

So say the engine batteries are 90% charged, but due to surface charge, they do have a voltage of 14.5v. Same with house batteries...say 80% charged.

The ACR won't disconnect for a while. The voltage has to drop first (surface charge dissipate).

I could see the house batteries drawing down the engine battery a bit before the ACR disconnects. Say 5% maybe.

Then the engine batteries sit around at 85% charged and sulphate.


Meh...it's a theory. I never said it was a GOOD theory. :)

Low voltage chronic undercharge due to diode isolator is a better theory.
 

Bikersmurf

Expedition Leader
The charge voltage didn't seem terrible with the diode isolator @ 14.1 v from the alternator. Now seeing 14.5-14.7 at the batteries, they'll charge up much more quickly. I'm also seeing the voltage once stopped to be much higher. 12.8v vs say 12.2v.

I'd not worried since it was plugged in nightly. However it seems clear that the Guest charger wasn't cutting it.

Time will tell for sure, but I think I'm on the right path. If the house batteries aren't going to die in 12 months regardless, I'll switch over to 6v golf cart batteries for the house batteries.

Any thoughts on how 4 series & parraled 6 volt golf cart batteries would respond to being connected to two starting batteries via ACR and a 215 A Alternator @ 14.5 V? Would they last? Should I have some form of charge controller?
 

john61ct

Adventurer
A cheap flooded Starter batt does not need coddling.

All significant charge sources' regulation should match the mfg specs for, and be directly attached to the House bank.

An ACR or Echo Charger then has no problem keeping Starter topped up no worries.

Most such devices isolate shortly after charge current is removed, built-in delays are a good thing.

Never mind the surface charge stuff.
 

rayra

Expedition Leader
given the ACR / surface charge theory, I'd maybe consider a manual cutoff to isolate the Starter battery when the vehicle is shut off. Use the ACR for its charging intelligent circuit. But lock it out (isolate the starter batteries) when not actively charging. It's not elegant, it's not automatic, but it stops the trouble until a better answer can be found. Just add a rotary cutoff at the starter positive terminal(s). Or where they are connected to the ACR.
 

john61ct

Adventurer
The Starter cranking draw can be higher, but brief.

If the ACR is still combining the two circuits after charging has stopped (taking any programmed delay into account)

and tgat is easy to check

then it is faulty and should be replaced.

Adding another redundant switch to a system that is already not fully understood is not IMO a good idea.
 

Bikersmurf

Expedition Leader
Quick update.

Now having an ACR and a three stage charger, the batteries are much happier. I connected the 3 stage charger up after only driving and using the Converter (Guest Charger). The Charger after its quick testing said 98% and within 5 minutes switched to Float mode. I'll continue to monitor them, but I believe regular use of the Charger to ensure they reach 100% after significant discharges will ensue their health... I'll know better in a year or 5 :)

The Diode regulator was likely 90% of the issue. It was doing more than slowing changing time... The batteries weren't seeing 14.5v enough to get a full charge.
 
Last edited:

Jdubucsd

Addicted to Espresso
I have a 1995 E350 Leader ambulance. I had the isolator under my seat. I had a local reputable auto electrician take mine out. And place a solenoid then only connects two rear house batteries and the two under hood batteries when the ignition is keyed on. When the ignition is off, the underhood and rear tray batteries are separated. And everything I have in the rear box runs off my two trays. I had bad diodes originally in my alternator. And thwre is also isually an always hot wire lead to systems in the back from the underhood batteries. My rear box clock timer had a constant hot wire and one other connection. I forget which one. I dont know if any of this helps. But good luck
 

SoCal Tom

Explorer
I have a 1995 E350 Leader ambulance. I had the isolator under my seat. I had a local reputable auto electrician take mine out. And place a solenoid then only connects two rear house batteries and the two under hood batteries when the ignition is keyed on. When the ignition is off, the underhood and rear tray batteries are separated. And everything I have in the rear box runs off my two trays. I had bad diodes originally in my alternator. And thwre is also isually an always hot wire lead to systems in the back from the underhood batteries. My rear box clock timer had a constant hot wire and one other connection. I forget which one. I dont know if any of this helps. But good luck

Reminds me of the time the diodes went bad in my E250. I was a poor college student, so I hooked up a constant duty solenoid I had on the battery positive to the fuse panel. Put a switch on the dash to power it. One day I get out of class and go to start the van and there is a big hole where the keys should go. Someone had tried to steal it, but gave up when it wouldn’t start. I got out a screw driver, flipped the battery switch and drove off. I always fantasize that the their was watching some where..
 

Forum statistics

Threads
185,534
Messages
2,875,619
Members
224,922
Latest member
Randy Towles
Top