How to Diagnose & Fix a Cargo Van That’s Not Holding Charge

Typically, your cargo van won’t hold a charge due to:

  • An old battery
  • Faulty alternator
  • A damaged or loose serpentine belt
  • Corroded battery wiring and terminals
  • Parasitic battery drain
  • Defective or blown fuse

Generally, this happens when something is wrong with either the battery or the alternator of your cargo van.

Pinpointing the root cause of the problem is usually done without any special equipment. Although modern vehicles have complex electrical systems and you may need to contact a qualified mechanic, especially if certain parts like the alternator have to be replaced.

To help you in diagnosing and even fixing your cargo van’s inability to hold a charge, in this article I’ll cover:

  • The primary reasons for a failed charge
  • How to pinpoint the exact issue
  • Fixing a battery that doesn’t hold a charge
  • Simple temporary hacks for quickly reviving a dead battery
  • Practical tips to maintain your vehicles’ charge
  • Ways to find out if the battery or alternator is causing problems
  • How long a cargo van battery charge typically lasts without driving


Main Reasons Why a Cargo Van Won’t a Hold Charge

These are the primary reasons for a failed charge, from the most to the least obvious:


1. Old and worn-out battery

Cargo van and car batteries don’t last forever, and they have to be replaced eventually.

Your average car battery will typically last around 2-5 years, which is mostly determined by the weather where you live.

After some time, batteries tend to develop bad cells, which doesn’t let them hold a charge.

Replacing a car battery is considered a normal part of vehicle maintenance and something that you should consider every few years.

Keep in mind that batteries usually die in winter, as colder weather requires more charge to power the engine.


2. Bad or Malfunctioning Alternator

The alternator is responsible for converting mechanical energy generated from the engine into electrical energy.

It also charges the battery while the engine is running, and they work in conjunction to deliver electrical power to the various electronics in your van.

However, a faulty alternator will prevent the battery from holding a charge, which will be noticeable when the vehicle dies even when you jump-start it.

Although alternators aren’t meant to be replaced as frequently as batteries, they still have to be replaced every 7 years (or around 150,000 miles) on average.


3. Loose or Damaged Serpentine Belt

Modern cargo vans are equipped with a serpentine belt that’s designed to transport power to various engine accessories.

It’s attached to various components such as the power steering pump, air-con compressor, and alternator.

Having a properly functioning serpentine belt ensures that the alternator works at its full potential to transfer charge to the battery when the engine is on.

But if it’s stretched or damaged, the alternator will produce an insufficient charge that can result in the battery not holding a charge.


4. Corroded Battery Wiring and Terminals

The battery terminals and wiring are prone to corrosion, even if your battery isn’t particularly old.

In particular, corrosion can build up on certain parts of the battery (e.g. the cables), which can interfere with the charging process.

The presence of corrosion will prevent solid contact, which will result in an insufficient charge

Proper regular maintenance of the battery can help prevent this, although if the corrosion has already built up, then you may want to have a mechanic inspect the terminals and wiring.


5. Parasitic Battery Drain

The term parasitic drain is typically used when all electrical components such as the lights are off, but the battery charge is still being drained.

This can be caused by a stuck relay or an accessory that’s plugged into a power outlet which is  always on.

Note that there could be only a small draw on the battery, which may go unnoticed for a long time.

Parasitic drains can sometimes go on for several months before your cargo van no longer holds a charge as it used to.


6. Defective or blown fuse

Modern vehicles have lots of different fuses, usually located in 2 fuse boxes to accommodate the various electronic components.

However, blown fuses are not uncommon, especially in high-mileage vehicles.

They become more fragile and worn out, which can result in a specific battery drain.

Fuses are easy to find and replace, although the exact location of the fuse boxes can vary between different cargo van models.


Diagnosing the Root Cause of the Charge Problems

Although your vehicle’s inability to hold a charge can be caused by different factors, you can try these methods to find what’s causing it:


1. Check the Cargo Van’s Headlights

Turn on your vehicle’s headlights and observe the following factors:

  • Normal brightness – This may indicate a faulty starter or poor wiring and is typically not caused by the battery.
  • Dimmed or no lights at all – This will most likely mean that your battery is either dead or in the process of dying.

A problematic battery will affect both front headlights, not just the one on the left or right side.

Any differences in the specific color or brightness between headlights on the same vehicle are usually caused by a corroded ground wire that’s part of the headlight assembly.


2. Inspect the Battery Terminals for Bad Connections

Open the hood, remove the battery’s plastic cover (if there is one), and perform a visual inspection.

Focus on the condition of the battery terminals and wiring, while trying to spot any signs of mold or corrosion build-up.

Slackened or moldy terminals are not an uncommon sight in older cargo vans.

If you do spot any corrosion or mold on the terminals, you can try to clean them with a sand-paper or wire brush to see if it improves the charging capabilities of the battery.


3. Test the Battery for Dead Cells

The best way to detect a dead cell is by testing the specific gravity of the electrolyte fluid inside the battery.

Here’s how to do it:

  1. Wear protective gear for your eyes and hands (safety glasses and rubber gloves)
    Note: Don’t let open flames go near the battery
  2. Grab a crescent wrench
  3. Disconnect the battery cables
    Note: Always disconnect the negative terminal (the minus) first
  4. Attach the battery to a charger and let it charge sufficiently
    Note: A 3-phase charger for lead-acid batteries works best
  5. Disconnect the charger once the battery is charged
  6. Grab a flat-head screwdriver
  7. Use it to remove the plastic caps located on top of the battery
    Note: Be very careful when doing this not to break any caps
  8. Get a hydrometer (most auto stores should have these)
  9. Insert its rubber tube into one of the cells
  10. Hold the hydrometer upright and start squeezing the rubber bulb
  11. Keep squeezing until the hydrometer is full with battery cell fluid
  12. Perform the same hydrometer test on each cell
  13. Read and compare the readings between the different cells
  14. A cell with or more than 0.05 less specific gravity than other cells indicates that it’s dead

Typically, having a dead cell calls for a new battery although you may still try to bring it back to life by adding Epsom salt or aspirin inside the cell fluid.


4. Perform a Voltmeter Test

Get a voltmeter and perform the following test on the battery:

  1. Turn off the engine
  2. Connect the positive current wire (red) to the positive terminal
  3. Connect the negative wire (black) to the negative terminal
  4. Check the voltmeter readings (should be around 12.6 volts)

A volt reading of more than 12.6 will indicate a properly charged battery, while anything below will point out a poorly charged or dead battery.


5. Check the Overall Condition of the Battery

Consider its condition by checking these two factors to figure out if the battery is:

  • Worn out and corroded
  • Old and past its life expectancy

Generally, a battery that’s older than 4 years will probably have run its course, and your best bet would be to replace it.


6. Inspect and Test the Alternator

If your battery appears fine, you may want to check the alternator next.

Consider the most common symptoms of a bad alternator:

  • Vehicle stalls shortly after being jump-started
  • Dimmed headlights
  • The engine won’t start
  • The Charging warning light is illuminated on the dashboard

One of the easiest and most obvious ways to spot a faulty alternator is through this test:

  1. Jump-start your van
  2. Leave the engine running
  3. If the engine stalls, then you’re probably facing alternator charging problems

Also, do a visual check of the alternator and try to find any signs of fraying or cracking in the cables there.

Any structural damage to the alternator or its cables may explain your vehicle’s inability to hold a charge.


7. Inspect the Drive Belt and Pulleys

First, do a visual check of the rubber belt (i.e. serpentine belt) that drives the alternator and look for any signs of wear and tear.

Then give it a gentle touch to find out whether it’s loose or not.

If you notice that your serpentine belt is slackened, you can be certain that it in’t creating a powerful enough spin to generate a sufficient charge.

A slipping serpentine belt might also generate noise from the belt pulleys.


8. Look for Any Blown Fuses

A blown fuse can prove to be the culprit, especially if your cargo van is older.

Try this to find out if that’s the case:

  1. Open the fuse box or boxes, depending on your vehicle
  2. Check if the starter motor and alternator fuses are blown

A blown fuse will have a visible gap in the wire inside the glass, and that’s how you spot them.


9. Consider Any Aftermarket Devices You May Have

An improperly installed aftermarket device such as an alarm security system can passively drain your battery’s charge.

Test your battery’s voltage with the device turned on and without it to try finding any abnormal drain.

Or get the help of an electrician to ensure that any aftermarket devices are correctly installed.


10. Run a Diagnostic Tool (OBD Scanner)

Running a diagnostic scanner might help you single out the root of the problem.

This tool will reveal any fault codes stored in the car’s brain, the ECU (engine control unit), or ECM (electronic control module).

You can either get a scanner yourself or have a mechanic check the vehicle for any fault codes.


How to Fix a Battery that Won’t Hold a Charge

A cargo van’s battery will always be the primary suspect when charge issues arise, and so it’s the part that’s usually replaced.

But there’s a great practical method to try and recondition a dead battery by yourself – here’s what you have to do:


Items Needed:

  • Battery charger
  • Voltmeter
  • Flat-head screwdriver
  • 2 big buckets
  • 1 gallon of distilled water
  • 1 lb of baking soda
  • 1 lb of Epsom salt
  • Toothbrush
  • Funnel
  • Steel wool or battery terminal cleaner
  • Protective apron, safety glasses and chemical-resistant gloves



1. Get ready and equip your protective gear

Switch the ignition off – the engine shouldn’t be running while performing this fix.

It’s also vital to ensure that you’re wearing protection for your eyes, hands, and the front of your body.

Be mentally prepared that you’ll make a small (or not-so-small) mess.

And try to work in a well-ventilated place if possible.


2. Prepare the cleaning solution

Get around half a pound of baking soda and mix it with water in a 2:1 ratio until you end up with a runny paste-like texture.

You’ll be using this baking soda-water paste to clean the battery and cover any acid spill.


3. Clean the battery terminals

For this step, you’ll need to get a toothbrush, steel wool, and your recently-made cleaning paste.

And here’s how to clean to terminals:

  1. Apply the baking soda and water paste to the terminal posts
  2. Grab the toothbrush (or steel wool for cleaning highly corroded terminals)
  3. Give them a nice scrub
    Note: Don’t panic if you see a foaming reaction, as this means the paste is doing its job
  4. Clean the terminals from the paste/foam
  5. Wipe and dry them off


4. Test the voltage before you continue

Check the voltage of the battery before proceeding to the next steps by doing this:

  1. Get a voltmeter
  2. Connect the positive (red) cable to the positive terminal
  3. Connect the negative (black) cable to the negative terminal
  4. Check the readings

A good battery will read 12.6 volts, although any voltage between 10-12.6 means that you can still recondition the battery.

Forget about trying to fix the battery if it delivers anything less than 10V and simply replace it.


5. Remove the battery and empty the cells

Here’s how to do it:

  1. Remove the battery from its tray
    Note: Keep in mind that cargo van batteries are quite heavy
  2. Remove the battery cover and the cell caps beneath it
  3. Get a larger bucket and 0.5-pound baking soda
  4. Slowly begin emptying the contents of each cell into the waste bucket
  5. Add baking soda to the waste bucket to neutralize the battery acid


6. Clean each battery cell

This is how to properly clean them:

  1. Pour the cleaning mixture (the baking soda and water solution) into each cell using a funnel
  2. Seal all the cell caps and attach the battery cover
  3. Give the battery a good shake for a minimum of 1 minute
  4. Remove the caps and cover
  5. Dispose of the cleaning solution into the waste bucket from the previous main step


7. Prepare the new battery cell solution

Here’s how to make the new cell solution:

  1. Combine 4 ounces of Epsom salt with 4 cups of water
  2. Stir the mixture until the water looks clear
    Note: You can use boiled water to speed things up
  3. Fill each cell with the salt-water mixture using the funnel
  4. Place all the caps and cover
  5. Shake the battery to ensure that the salt is evenly distributed


8. Get a charger to recharge the battery

Before you start recharging your vehicle’s battery, make sure to remove the battery caps.

That’s because the electrolyte solution that you just poured into the cells may overflow from too much heat during charging.

And this is how to properly recharge your reconditioned battery:

  1. Put the charger as far away from the battery as you can
  2. Connect the charger to the battery at a speed of 12V and 2 amps
  3. Keep it recharging for 36 hours


9. Do a final test to ensure the battery is working

Once you’ve charged your battery for 36 hours, remove the charger and perform the following test:

  1. Use the voltmeter to check the readings again
    Note: If the battery’s voltage is below 12.42V, charge it for 12 additional hours
  2. Put the ignition to the On position
  3. Turn the high beams on
  4. Wait for several minutes
  5. Perform another voltmeter test while the battery is under load
  6. A successfully reconditioned battery will read 9.6V

It’s worth mentioning that you can probably repeat this reconditioning process several times.

However, this is more of a temporary fix as you’d eventually need a replacement if your battery is too old and worn out.


4 Simple Temporary Hacks to Revive a Dead Battery

Before you try the following tricks for reviving a dead battery, I have to warn you that they’re not permanent solutions.

These simple hacks are only meant to get you back on the road so that you go to the nearest auto parts store or repair shop to get a new battery.

And once you’ve successfully revived the old battery, remember to keep the engine running until you have bought a new one to not risk getting stranded somewhere.


1. Jumpstart the Cargo Van

Get a pair of jumper cables and use them to connect your dead battery to a battery booster or a functioning battery e.g. from another vehicle.

Just a word of caution, never try to jumpstart a frozen battery as it can literally explode.

Instead, thaw it first and then give jumpstarting a try.

Don’t turn the engine off if you succeed in reviving the vehicle.


2. Boost the battery cells with Aspirin

Although it might sound insane, putting some crushed Aspirin (acetylsalicylic acid) into the battery cells can boost the electrolyte mix.

Here’s how to use the aspirin method:

  1. Get 12 Aspirin tablets (around 325-500 mg) and crush them
  2. Dissolve the crushed tablets into 6 ounces of warm water
  3. Pour equal amounts of the aspirin mixture into each cell
  4. Optional: If needed, add more water to ensure all cell plates are fully submerged


3. Fill the cells with some distilled water

You can use distilled water to top the electrolyte solution level inside the battery cells to possibly give you a few extra turns of the engine.

The key is to pour enough distilled water to ensure that the plates are fully covered to have more reaction area for improved charging.

However, this method won’t work if you use tap water as it’s not a good conductor of electricity.


4. Add some Epsom salt to the electrolyte mix

Epsom salt (a.k.a. magnesium sulfate) is a chemical compound that’s soluble in water.

It can be found in various grocery and drug stores, as well as home gardening centers.

The addition of a strong acid like the Epsom salt to the electrolyte mix inside the battery may help to provide sufficient charge to get the engine going.

Here’s how to utilize the Epsom salt method:

  1. Dissolve 1 part of Epsom salt with 3 parts of warm water (1:3 ratio)
  2. Pour some of the dissolved mixture into each battery cell
  3. Make sure that all plates are submerged by 1/4 to 1/2 electrolyte


Practical Tips to Maintain Your Vehicles’ Charge

Vehicles are meant to be used, and when you don’t drive your van very often, it can lose charge and give you trouble when you try to start the engine.

Thankfully, these practical tips can help you to avoid a flat cargo van battery:


1. Utilize a battery conditioner or trickle charger

Battery conditioners and trickle chargers can be used to preserve your battery’s charge when not driving your van for long periods of time.

These devices can also help by stopping parasitic drain from sources such as dash cams and immobilizers.


2. Disconnect any sources of parasitic drain

Your cargo van’s battery might still lose charge, even though the engine and all electronics appear to be off.

This is usually caused by some type of parasitic drain e.g. an aftermarket device.

That’s why it’d be wise to disconnect anything that may drain your battery, like a dashcam or an aftermarket immobilizer.


3. Let the engine run for at least 15 minutes

Short journeys are far from ideal for a battery’s charge, especially if it’s already old and beat up.

That’s why it’s usually recommended to drive for at least 15 minutes at a time so that the battery hopefully manages to achieve optimal charge.

But you can also just let the engine run for a minimum of 15 minutes if you’re not keen on driving just for the sake of it.

What’s important is to simply keep the engine running as that’s when the alternator works by supplying charge to the battery.


4. Always check for any lights that might be on

Make it a habit to visually inspect your cargo van every time you walk out of the vehicle.

The primary suspects to look for are vanity mirror lights and dome lights.

Leaving the headlights on is no longer an issue as modern cargo vans automatically switch the headlights off immediately or shortly after turning off the engine.

Still, if you drive a really old model then you might want to check if it has this feature to avoid unnecessary battery drain.


5. Keep the battery clean of any dirt

Make sure to regularly clean the exterior of the battery with a rag or paper towel.

Grease and dirt accumulation can trap heat around the battery, which can increase the temperature.

And excessively high temperatures can make the battery fluid evaporate, resulting in charge problems.


Bonus Tip: Disconnect the battery when away for a longer period of time

Consider removing the battery if you’re planning to be away without your cargo van for more than 2 weeks.

This way you’ll ensure that the battery’s charge isn’t drained while you’re on a vacation or elsewhere, and you’ll be able to use your vehicle when you return without worrying about the battery dying.


Symptoms of Dead Battery vs Bad Alternator

Signs of battery and alternator issues often go hand in hand when a vehicle is unable to hold a charge.

Here’s how to differentiate between the two:


Dead Battery Symptoms

Note that even if your vehicle’s battery is old and worn out, it still won’t damage the alternator.

  • Dim dashboard lights
  • There’s corrosion on the battery
  • The battery is too old (over 5 years)


Bad Alternator Symptoms

It’s worth noting that a bad alternator can easily overcharge and damage even a brand new battery.

  • Gradually dimming interior lights while the engine is running
  • A specific smell of burnt rubber or hot wire
  • Headlights change brightness as you accelerate
  • Growling sounds
  • Engine stalls shortly after being jump-started


Most Van Batteries Last 2 Weeks Without Driving

Most car and cargo van batteries in good condition can retain charge for up to 2 weeks when connected to the vehicle and without driving it.

However, even a brand new battery will fully discharge if left in a vehicle that’s not been driven for 2-3 months.

Even if you don’t plan on using your cargo van for the next several months, you should still recharge the battery every week.

You can recharge it either indirectly by letting the engine run for at least 15 minutes or directly by using a trickle charger.



The most likely reason your cargo van won’t hold a charge is an old and worn-out battery.

Automotive batteries typically last around 2 to 5 years before they have to be replaced.

However, parasitic drain (e.g. from aftermarket devices) and parts such as the alternator may also cause charge problems.

Usually, you should be able to diagnose and possibly fix the problem yourself with the help of this article.

But if your van still won’t hold a charge, then you might want to visit an auto repair shop or call a qualified mechanic.