Batteries are appx 3 yrs old Walmart Maxx 65. 850 CCA rated. Recently had truck sitting for 5 days and forget the OBD module was plugged in which make the battery go down some.

Tried to start but not able after GP cycle due to low power. Got it jumped and started and drove foe 20 plus min at hwy speed.

So truck sits for like 7 days but I had put a small solar charger in windshield plugged into cig lighter and when I tried to start it was not going to work. Finally got jumped and running and 20 min at hwy speed back. Checked volts next morning and got 11.8
took to Walmart to check. They show like 664 CCA on each and say they are good just need good charge.

So when does the cca get low enough to need chage out? I am like 2 days after 3 yr full replace warranty


Thanks

 

Practically speaking I think you've already stumbled across it. When they don't start the engine is when the CCA is too low. You said yourself you'd left stuff plugged so lets not go assuming they're dead yet until they've been trickle charged. Maybe take them both out and clean them up, check the water levels and do a position swap while you're at it.

 

Those solar chargers barely put out any amps and will not charge a battery, they barely maintain it. Depleted batteries need to be either fully charged with a charger or driven for a long time to fully recharge them. How long depends on how depleted they are but at least 8 hours, maybe more. Divide the battery amperage by the alternator amperage and you are getting close but don't forget that you need some of what the alternator is putting out to run the vehicle so you don't get the full dose from the alternator to the batteries. Driving for 20 minutes only puts a superficial charge on them and doing that repeatedly may not be good for the health of the batteries. I am not certain on that one but I treat them as such to eliminate a premature death.

 

I can hook the batteriesbto my solar panel on truck cap to mppt that puts out like15 amps that should give it a good deep charge and renting we see.

 

See if you can swap them out since you are so close to the warranty period. You might get lucky...

For me, I lost all confidence in FLA (flooded lead acid) batteries a few years ago. I have changed all of my vehicles and lawn mower out to AGM or lithium batteries. For the truck, I installed a set of NorthStar AGM batteries, but would also trust Odyssey Extreme. They are pricey, but they have been rock solid for me for the past 4 years and I have left the truck sit for 4 months at one point during the camping off season.

Also, I don't have to lug batteries in and out of the truck and into the store. The time, effort and headache of a warranty replacement is not in my purview when selecting a product.

If I make it to 6 years with the NorthStar AGM, I am even money. If I make it past 6 years, I am saved money, saved time and saved headaches. In addition, we boondock with our 5th wheel, sometimes 50+ miles from anything with electricity. So, reliability and confidence were paramount.

If Wal-Mart tells you to pound sand and you want to have a set of batteries that are reliable, check out the link below.

Link: AGM Group 65 Battery Comparison

 

This^^^. 20 minutes of run time doesn't even replace what it took to start the truck, you are losing ground..

 

Good link there Sous, I think the time has come for AGM to replace FLA which is my plan as soon as these Motorcraft FLA's die.

 

You may want to check for a draw on the electrical system. They seam to be becoming a more common issue lately. I tracked mine to the factory head unit, and I've read here of others w/ similar issues. Could turn out to be the root problem. Here is a link for the test procedure if you're unfamiliar.

Testing for Parasitic Draw with a Multimeter | Test Meter Pro

 

He left his OBD dongle in. I got that T-shirt too.

 

So have them hooked to my solar panel and will let them sit charging for 3 tob4 days as we go out of town.. 15 v at 14 amp when this was taken.

 

14 amps should cover it...in about 100 hours of good daylight.

 

100 hours??? I charge my 220 ah golf cart batteries that get to 12.3 volts with 440 watt 12 volts 10-15 amps in 5-6 hrs or less.. these standard batteries charge up faster than the heavy azz lead batteries i use on teh RV. when i just checked the amp was down to 5.5 and volts at 15 which mean the mppt is in bulk charging.. so it will now taper the amps with volts high to finish the charge. the 335 watt 24 volt panels actually puts 32v olts to the mppt which can turn that into extra amps.. the panel itself is rated for 8.8 amps so when you reduce the volts you increase the amps. after a couple days of good sun on the panel that battery will be charged as it can get. then i will let it sit for some hourst to see where the volts settle out.. this will prevent the lack of use drain.. might hook up my harbor frieght trickle charger after this to prevent another drop in volts.

 

What are them golf cart batteries starting at? and 220 amp vs 2x850 amp is a plenty big difference.

 

When was the last time you got all of your battery leads OMG clean? I don't mean just at the batteries, I mean the other ends as well.

 

Also please keep in mind that alternators are for topping off your batteries not charging them. You well take significant life out of the alternator if not kill it making it work that hard to charge batteries that have been taken down that far. Yes jumping your truck will get it started but you are damaging your alternator making it charge that deep of a drain. Invest in a good battery charger, not a maintainer as maintainers are good to keep them toped off and de-sulfated if you choose that type sometimes you can get a good all in one.