JoeAllie

I have a 1991 4x4 pickup that has not run for 8 - 10 years. About 3 years ago the battery was replaced after the timing belt was replaced. The truck was only started every 3 to 4 months. I just had the emission tested, it passed. It will be ready to be put back on the road in about 2 months.
My question is - If I start the truck , how long does it need to run so the battery doesn't run down ? How long does it take the alternator to recharge to battery ? The battery seems to be getting rundown .

Thanks for the help.

Odin

Don't rely on the alternator to recharge your battery if it's getting low, the added stress of recharging a low battery will reduce its lifespan. You shouldn't think of your cars alternator as a charger. Think of the alternator as more of your power supply and a maintainer while the vehicle is running.

If you're not going to be driving the vehicle much you need a battery maintainer. I've tested a lot of them and while the Battery Tender JR was quite popular the now China produced Tender JR is getting a bad rap for early failures. To top it off the company has changed their warranty to make getting a replacement about equal to the cost of just purchasing a new one. If you take the time to read through all the negative one star reviews and the comments being made on Amazon you'll notice a pattern emerge.

After testing quite a few different brands I ended up liking the Ctek 0.8 for maintaining a regular (wet) lead acid filled battery and the Yuasa Smart Shot 900 for AGM batteries. AGM batteries require more voltage when being charged and maintained to bring them up to optimum capacity so I opt for a different charger. My guess is the new Battery MINDer 2012-AGM would be ideal for AGM's but they cost more. The charger/maintainers below 1.5 amp's aren't meant for charging a deeply discharged car battery but they do work great for maintaining an already charged battery around it's peak.

The best thing I know of for a battery is to get it out of the weather by placing it in the garage and hooking it up to the maintainer. They can only be ran down so far and so many times before they want to stay down and both high and low temperatures don't do them any favors.

If you're not going to use the truck much there's a more serious and costly thing to think about and that's the crappy 10% Ethanol pump gas in your tank. That stuff doesn't really like to sit unused and starts to suffer from separation a lot faster than what used to be the norm plus it tends to collect water. That stuff can ruin all kinds of stuff in your fuel system that isn't fun to clean or in some extreme cases replace.
Less MPG, shorter shelf life, early damage to fuel systems, those are reasons why people who read the research or experience the damage in their lawn mowers, chain saws, leaf blowers, motorcycles, cars and trucks oppose government mandated ethanol at our gas pumps.

If you're going to let your vehicle sit with pump gas in it for maybe six months and then use it to the point where you consume a whole tankful you might be ok. If it's going to sit for a year with the same gas you might think about either adding a fuel stabilizer or my favorite, getting a tankful of non ethanol super. Run all the E10 out then fill it up and make sure the engine is running on it before you shut it off for storage. A source of non ethanol gas, also known as clear gas can be found at pure-gas.org or buyrealgas.com

reallifedog

To Odin's point on gas, you can also find "recreational gas" near lakes and thats typically ethanol free.

Odin

Correct, those stations should also be listed on the pure-gas.org site. At least they are in my area.

mct75

The first time you run a battery all the way down (less than 10 volts), its days are numbered. Any time you're going to store the vehicle for more than 2 weeks or so I would disconnect the battery, and charge it once a month at minimum. Car batteries like to stay at 80 to 100% charge all the time.

muddpigg

iTrader: (1)

Not gonna argue the benefits of best options for storing a vehicle.

But if you run a battery "dead" and have to jump start the vehicle then usually 20 to 25 minutes driving will charge battery back up. Of course how long the battery stays charged is dependent on several factors. Even battery type matters.

Just starting a vehicle for 5 minutes will kill battery over time, alternators don't produce near their rated value at idle.

Good luck with getting rig back up to prestorage conditions.

Odin

True. If they've sat at deep discharge levels (10v and under) for long they've been hurt, especially if it's an older battery.

It's been said that some batteries can be desulfated to get them back up to a good operational level but it works best when they aren't that old and only lite sulfation has occurred. If it's sat at 10v and under for a week plus, desulfation probably won't work so well.

I have one of the first Battery MINDer's built specifically for AGM batteries (pn 12118 no longer produced) that incorporates a desulfator but I haven't been able to try it on a deeply sulfated battery because my 8 yr old Yuasa motorcycle battery is still working great. During the winter my bike sits for months at a time. I remove the battery so there's no drain, place it indoors and keep it on the maintainer.

I did the same when I had two running cars and didn't have a failure. I did get a newer CarQuest battery with my truck but I use my old Optima in it so the CarQuest is now sitting on a maintainer. I guess I'll see how long that CarQuest battery lasts lol. Even though I have too many chargers I might see if I can find a cheap priced Battery MINDer 1500 for it because it has temperature compensation for extreme hot or cold conditions.

jennygirl

^^^ This

And also why I always use high quality deep cycle / AGM. Zero worries about running the battery all the way down while camping or letting it sit. A few less cold cranking amps, but who gives a crap anyway- 4cyl starters are small. With a high quality deep cycle battery, it is no problem at all.

Funny how many people do not understand the loss of capacity from discharging a normal car battery too far. The insides literally fall to pieces when the voltage drops too much, and it's permanent.

wyoming9

iTrader: (1)

I never had that problem mine just freeze and crack.I am getting better I bring them inside and put them under the bed only because no more room under the table.

I will never unless it is a drop dead emergency rely on a alternator to charge a battery that is really discharged .Then would buy a new battery first place I could.

I would rather replace batteries then alternators.

muddpigg

iTrader: (1)

This post has had lot's of good information in it. I've learned something new.

Odin

There's lots of information about batteries over at batteryuniversity.com and batterystuff.com.
...BattertStuff also has a pretty good amount of information about battery chargers and their applications as well as chargers for sale. Some of their prices can be beat though.

scottrweeks

Use a battery charger to charge the battery or take it to a parts store. Many charge the batteries for free