Hi all,

I just had my trans rebuilt and both batteries died while the truck was at the shop. We ended up replacing just the passenger side battery and the engine now cranks super fast. I have driven the truck approximately 50 miles and tested the drivers side battery today. The truck sat for 36 hours prior to the test. Load meter for 10 seconds was in the green - around 11 volts. Hydrometer readings were around 1225 (Fair) in each cell. I have read past posts were everyone recommends that both batteries be replaced at the same time. Money is a little tight right now plus I don't really want to dispose of a battery that still has some life to it. I plan to put it on a trickle charge tomorrow.

Can anyone tell me why both batteries need to replaced at the same time? I am thinking that the alternator is recharging them both and the starting system is going to draw what it needs regardless of independent battery state. At what specific gravity do you think the battery is fully charged and are OK to to keep? I have had the truck since 11/07 and I don't know how old the Motorcrafts batteries are.

Has anyone used galvanized battery terminal bolts and nuts? I know they are less prone to corrosion around water but not sure around sulfuric acid. Are they better than untreated or zinc coated steel for this application?

Thanks...

Neil

 

the old battery will shorten the life of the new one by robbing power from the new battery...keep the week battery for a second car or a friend in need..

 

If $$$ is tight, it's tight. Trickle charge the DS battery until it is in a state of over charge and leave it that way for a day or so. This will reverse some of the sulfation in the battery. Make sure the acid levels are topped off... with ACID, not water (it's sold at most of the auto stores, albeit behind the counter). Make sure the connections are good and tight, use a thick grease for your corrosion protectant, can't be beat. I like using the felt washers around the battery posts, and use axle grease all around the connection, never let me down. FYI, when you coat steel with Zinc, the result is "galvanized"

 

As I understand it, older batteries with sulfated plates tend to have lower standing voltages. If you hook up a newer battery with the older battery in parallel as ours are, the old battery will pull down the new battery voltage to its level, causing the new battery to start sulfating faster, especially if left sitting for a while. I would bet that if you drive and thus charge the batteries daily, the effect would be minimal or at least minimized. However, if you let the truck sit for any length of time, you should probably keep a trickle charger on it so the float voltage stays above 13.2.

If you have a dead cell in the older battery, you have a bigger problem. I would charge them up, then disconnect them both and let them sit overnight checking the voltage in the morning. If the older batter has a substantially lower voltage then the newer one, I would replace it. If they are about the same, i wouldn't worry too much for now.

 

I will trickle charge the old one to see how much I can bring up the specific gravity. After I let the battery rest, should I compare standing voltage (no load/no connection) or load test voltage to a new battery?

As for the bolts, I went to Home Depot and they have run of the mill 5/16s bolts that appear steel. I am unsure if the have a zinc coating but the matching nuts do. They also sell dull gray galvanized bolts, nuts and washers that are more expensive than the run of mill stuff. Which would you use for battery terminal bolts?


Thanks...

Neil

 

6 one way 1/2 dozen the other, if $$$ is an issue, go with the cheapest bolts and make sure you grease everything up good. I think it's better than galvanized anyway.

You'll want to just let the batteries rest, then test their at rest voltage. Voltage testing will give you a good indication of how the battery is operating as a "unit" (6, ~2 volt plate stacks)... the specific gravity will tell you how the individual 2 volt plate stacks are doing.

 

Specific gravity is a much better test of a battery's condition. Voltage is just a "quick and dirty" way of checking. I would let the batteries rest overnight before checking. Ya lost me on the load testing, probably since i never had any equipment that would load test batteries.

 

I have a load tester bought from either Harbor Freight or Cummings Tools. I'll check today.

I looked at the passenger side battery that was replaced. One of the cells was really low or almost empty of electrolyte. I added distilled water and will try to trickle charge it. I guess I should have posed the question here before adding the distilled water vs. going out and buying acid. 20/20 hindsight + why put more money into a bad battery. Do you think I'll have any luck saving this battery by trickle charging it or should I consider it a lost cause? Again, I have no idea how old it is. It is at least 2 years 3 months (how long I have owned the truck).

So the cheaper bolts are better than the galvanized ones? Thanks for the info.

Neil

 

If the plates were dry, I think it's a lost cause. I've actually never heard of adding acid to batteries, but at least water is cheap. Myself, I always replace flooded lead-acid batteries at five years, no matter how good they seem. From what I've read, they become unreliable by then. In my opinion, yours were at least 1/2 way to unreliable, probably most of the way there. I'd probably get a new battery, same size and model as the one you just bought if I planned to keep the truck, even if I was broke, which I always am.

 

My 99 7.3 p.stroke has been parked while we are on extended winter vacation.
My buddy has been using a standard 10 amp charger to keep up the batteries on some of our vehicles including this truck. He advised me that he mistakenly attached the charger + to the vehicle - terminal, and the charger - to the + vehicle terminal. He said he heard the radio come on although the truck was off. He then did some tests and discovered that while parked there was about 1 amp of discharge occurring. After numerous testing he feels that the culprit is likely a diode for the radio. He has disconnected the radio, recharged the batteries and the discharge level is very minimal. He said he's done that a few times so determined it's the radio, or diode inbetween that initated the drain problem while parked. In my simplistic mind, not really understanding electronic, I find it hard to blame the radio if it's off, and the truck is parked. Perhaps one of our forum electrical gurus can enlighten me. Thanks CJ

 

Well, i'm sure the grease you use works well, but Noalox beats it easily!

IDEAL INDUSTRIES, INC. - Noalox® Anti-Oxidant Compound

A few years back, an electrician friend of mine replaced the breaker box at my house. He used Noalox and when I asked about it, I learned it's a staple that all electricians use in their trade. It stops oxidation and actually conducts electricity.

I soon forgot about it until I saw Jim (megawatt) mention it in a thread about a year or so ago.

You can get it at your local Home Depot or Lowes.

Stewart

 

Ya probably should have started a new thread on this and the reversing polarity thing got me confused. Put leaving a charger on a battery, unless it's a "smart" charger, will boil them dry and destroy the battery.

 

You know, your right (I mean... you already know that )

Are there different types of that stuff? Seems I remember one that looked like graphite and I'm sure that stuff would be perfect, but I also recall some of my electricians using this stuff that looked almost like jelly. Discounted it due to the appearance that it would get "runny" once hot. I've used Di-electric grease with mixed results (washes off to easy when I clean the engine) so I reverted back to thick ole sticky axle grease. Now you know the "rest of the story"

 

Not to my knowledge.

When I bought the stuff at Home Depot, there was only one choice.

Understandable.

Another reason not to use dielectric grease is because it's non-conductive. That's why it's great to use on spark plug boots where the boot connects to the plug, because it insulates and protects from stray current

Even though it would get squished out (there's a professional technical term...squished out...LOL), a non-conductive grease isn't something I would want between my terminal and my cable clamp.

Stewart

 

Opps, swing and a miss... Now looking over what I posted, I neglected to explain... I clean the terminals well, secure the cables good also, THEN coat the entire connection! Rational is to keep the water away from the exposed metal. That ole grease ain't worth a pinch of puppy poop for conduction.