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Battery Load Tester

maxwell11
Explorer
Explorer
The motor on my 2005 Dodge diesel was not kicking over as fast as it had been the last few days.

got back from Christmas vacation and it would not start,

I disconnected each positive lead from the batteries and charged up each battery.
next day took it down to the auto parts store to get the batteries check as they were installed on October 2011.

Sales clerk disconnected one positive clamp, then using a Battery Load Tester checked both batteries, both batteries test bad under load.

so I bought new batteries. but got $60 rebate on the old ones.

however, after I got home I got to thinking,

even thought he showed me they failed on his "battery load test machine"

I really did not understand why they were still starting my truck after the battery recharge I gave them the night before, if they wre bad.

also, if one battery had gone bad, what was the likely hood, both batteries were bad???????????

however, if one was bad I was going to change both out for new batteries.

I am now thinking about buying me one of those Battery load test machines.

anyone else have one and use it,

was I taken in on the old bad battery load test trick, maybe I should have had him test these new batteries I bought on his machine, before I left the premises ??????

ah well, the old truck starts fine now with plenty of zip,
15 REPLIES 15

Wes_Tausend
Explorer
Explorer
...

I had some trouble with mine, but I think it was just corrosion. I left them sit for about 3 weeks without a trickle charger which I usually don't do and they wouldn't even crank to start in 35F weather.

Earlier in the year, I think I sprayed some anti-corrosion on them as an after-thought because they looked so good yet and I was in a hurry after working on some other batteries. Then I promptly forgot about them since they looked done. Then I ended up working in the cold.

With headlights on, one terminal dropped 4+ volts across the post-to-clamp. I thought it a little odd that the truck did not start with the other battery but the system was probably severely undercharging if the alt voltage fooled it as high when it wasn't getting into the batteries. A good cleaning and charge and they seem fine now. I won't really know till spring, or even next fall, as I seldom start it in winter unless the Excursion V-10 is out of service.

I normally trickle charge the batteries constantly when they aren't used. The OEM battery in my previous Ranger sized pick-up lasted about 15 years this way. The idea is to never let the batteries drain down at all and prevent sulphation. When peaked out by a trickle charger, such batteries also seem to crank in winter like in summer. The most common one I used was a $5 sale Harbor Freight unit that was voltage limited, but I also have a couple of $20 Sears sale Schumachers now.

A good source of info is The 12volt Side of Life (Part 1). Don't miss Part 2.
The chart below is taken from the site:

Using any reasonably accurate digital voltmeter, one can check the percent of charge of RV batteries or, in this case the voltage of the diesel system after the headlights have been on a bit. Good batteries maintain decent voltage longer and a good time to benchmark thee standard battery is now since they are new. Fold the info into your vehicle owners manual. Some years down the road, when you have reason to doubt the batteries integrity, the measurements can be checked against the new battery measurements. Even cranking voltage can be measured so not only the sound, but exact loss can be determined.

Harbor Freight has a small cheap meter, that works and they often sell it for $5, or are even free. I bought one for $3 and gave it to my buddy after I calibrated it against a good Fluke meter. I fine tuned the HF meter on the inside pot to read exact against the Fluke standard, but it was only .1 vdc different, pretty close to start. Then just use the chart above to monitor your RV or parked truck. Best to leave a trickle charger on all the time. I believe batteries sulphate faster in summer.

Wes
...
Days spent camping are not subtracted from one's total.
- 2019 Leprechaun 311FS Class C
- Linda, Wes and Quincy the Standard Brown Poodle

Turtle_n_Peeps
Explorer
Explorer
Batteries start to go bad the minute they come off of the assemble line.

It's not like they are great, great, great, great, bad.

It's more like they are great, great, good, good, ok, ok, bad.

In other words, much like people, they slowly wear down and wear out over a lifetime. :B

I take old batteries out of my diesels that won't pass load test and put them in my equipment that I run once a year. I can get several more years out of my batteries doing this. ๐Ÿ™‚

If you want to buy a load tester I suggest you buy a newer type electronic model rather than the old carbon bank types. Last time I checked one could get a nice new electronic model for about 75 to a 100 bucks.
~ Too many freaks & not enough circuses ~


"Life is not tried ~ it is merely survived ~ if you're standing
outside the fire"

"The best way to get a bad law repealed is to enforce it strictly."- Abraham Lincoln

enblethen
Nomad
Nomad
OP has not said what temperature he was in. Diesels don't turn over very good when cold. They need at times to have block heater on.

Bud
USAF Retired
Pace Arrow


2003 Chev Ice Road Tracker

larry_barnhart
Explorer
Explorer
maxwell11 wrote:
The motor on my 2005 Dodge diesel was not kicking over as fast as it had been the last few days.

got back from Christmas vacation and it would not start,

I disconnected each positive lead from the batteries and charged up each battery.
next day took it down to the auto parts store to get the batteries check as they were installed on October 2011.

Sales clerk disconnected one positive clamp, then using a Battery Load Tester checked both batteries, both batteries test bad under load.

so I bought new batteries. but got $60 rebate on the old ones.

however, after I got home I got to thinking,

even thought he showed me they failed on his "battery load test machine"

I really did not understand why they were still starting my truck after the battery recharge I gave them the night before, if they wre bad.

also, if one battery had gone bad, what was the likely hood, both batteries were bad???????????

however, if one was bad I was going to change both out for new batteries.

I am now thinking about buying me one of those Battery load test machines.

anyone else have one and use it,

was I taken in on the old bad battery load test trick, maybe I should have had him test these new batteries I bought on his machine, before I left the premises ??????

ah well, the old truck starts fine now with plenty of zip,



To me you did the only correct thing to do. You bought 2 new batteries.

chevman
chevman
2019 rockwood 34 ft fifth wheel sold
2005 3500 2wd duramax CC dually
prodigy



KSH 55 inbed fuel tank

scanguage II
TD-EOC
Induction Overhaul Kit
TST tire monitors
FMCA # F479110

FishOnOne
Nomad
Nomad
maxwell11 wrote:

I do try to buy USA made items when I can, even if they cost a bit more, might save some old boy or girls job.


Well said and probably goes towards the 2016 Top Statement of the Year Award. :B
'12 Ford Super Duty FX4 ELD CC 6.7 PSD 400HP 800ft/lbs "270k Miles"
'16 Sprinter 319MKS "Wide Body"

maxwell11
Explorer
Explorer
I did not mention the battery brand I bought as I did not want to start a battery war.

but as most know the battery brand Autozone sells is Duralast

I when with that brand before because they were made by Johnson Controls in the USA.
however, I am not so sure Johnson Controls still makes the Duralast battery brand in the USA
I tried to look it up buy found no current data, all info I found was old 2009 back.

I do try to buy USA made items when I can, even if they cost a bit more, might save some old boy or girls job.

mbopp
Explorer
Explorer
The poor mans load test is to disable the ignition or fuel pump and crank the engine for 15 seconds while monitoring the voltage. It's been a while since I turned wrenches so I'd have to look up the acceptable minimum voltage under load after 15 seconds.
2017 Grand Design Imagine 2650RK
2019 F250 XLT Supercab
Just DW & me......

gkainz
Explorer
Explorer
just had to replace the OEM batteries in my 2007 Ram CTD. Stuff just doesn't last like it used to ๐Ÿ˜„
'07 Ram 2500 CTD 4x4 Quad Cab
'10 Keystone Laredo 245 5er

SCVJeff
Explorer
Explorer
So to answer the question, yes I have one, I think it's rated at 100A. It's got a big ol' carbon pile inside and a meter that reads in volts as well as a red/ green graph that shows condition after full charge, followed by an (X) seconds load test. Harbor freight has two different models. Both get REALLY hot REALLY fast.
Jeff - WA6EQU
'06 Itasca Meridian 34H, CAT C7/350

FishOnOne
Nomad
Nomad
The general rule is to change out both batteries even if only one is bad.

Bottom line for you is you were able to notice the starter wasn't turning the engine over as fast and that's a good barometer that the battery/s were on there way out as long as you know your alternator was charging to the correct voltage.
'12 Ford Super Duty FX4 ELD CC 6.7 PSD 400HP 800ft/lbs "270k Miles"
'16 Sprinter 319MKS "Wide Body"

45Ricochet
Explorer
Explorer
You might mention the brand of battery you replaced the OEM's with that failed in only what 4 years!! My OEM's lasted 7-8 years and still load tested fine, but I didn't want to chance it any longer with winter setting in. Rams are usually pretty easy on batteries so 4 years is a pretty short life IMO.
2015 Tiffin Phaeton Cummins ISL, Allison 3000, 45K GCWR
10KW Onan, Magnum Pure Sine Wave Inverter
2015 GMC Canyon Toad

Previous camping rig
06 Ram 3500 CC LB Laramie 4x4 Dually 5.9 Cummins Smarty Jr 48RE Jacobs brake
06 Grand Junction 15500 GVWR 3200 pin

enblethen
Nomad
Nomad
What was the ambient air temperature at each time?
Did you have your engine heater on? Not sure what temperature Dodge says to turn it on at.
I remember reading about some bad cables on the dual battery set up. I would test them.
Most of the load tester are not able to go over 500 amp. Harbor Freight Sku 5911929 for example. Higher ones get expensive.

Bud
USAF Retired
Pace Arrow


2003 Chev Ice Road Tracker

2003silverado
Explorer II
Explorer II
I think between you noticing the truck not turning over as fast and the no start condition, your batteries were on the way out.

I also understand your skepticism of the load testers used at auto parts stores. I felt the same way when they said my battery was bad. While im sure their propietary machines err on the side of replacing the battery, I highly they are completely crooked.

Batteries are not something to gamble with and you did well to replace both.

CA_Traveler
Explorer III
Explorer III
4+ old batteries that failed the load test - The very best option is to replace both even if one had some life left.
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland

Bob