Fried battery, what is a good battery charger?

[scot850]

Somewhat general question but having had a nasty 'potential' moment with an 'intelligent' battery charger (clearly with dementia) that just fried my Volvo battery.

I have a spare battery (Volvo OE which here is an Interstate brand) which I put on charge to use after standing for a while (it was stored fully charged).

The charger has a regenerate feature but this was not activated as far as I know. When checked the battery was at 70% charge, and 10.5V. The charger was running at 4A. All normal as per the 3-4 times used before.

Next morning my wife went out to the garage and came rushing back in as there was a terrible smell in the garage. I went out and the battery was smoking/boiling!! For some reason it had charged to a 25A charge on the battery all by itself.

I always loosen the battery cell caps where possible when charging at 4-6A as I had the previous experience of a battery exploding on me after charging with caps closed. I can only imagine what could have happened if I had not done so in this case also.

Bottom line, battery was boiled down to well below the top plates. I tried refilling and re-charging but strangely the charge just continues to drop. It is almost like charging the battery is doing the reverse!!

To charge this I used my old stand-by charger which is a basic machine with 2A or 6A settings.

So, having spoken to the manufacturer (well reseller) Canadian Tire they have asked me to return the tester to evaluate it in case of a design or manufacturing flaw. Naturally I won't use the Motomaster Intelligent charger again, so they refunded me as it was under warranty (2 years into 3 year warranty). They are also sending me a gift card to replace the battery.

I had a 'pulse' charger for 15 years or so in the UK prior to moving to Canada and this intelligent charger was the first one that came near to that on I had seen in years. I liked the pulse charger as it saved many batteries over the years and I regularly get up to 10 years in many cases on my batteries.

Can anyone recommend a good pulse or 'Recharge capable' battery charger? The only one I have found so far is a Dewalt 80A jump-start/recharge/dual charger. The reviews are mixed and the main issue is poor quality and performance/lifespan.

Like always I am happy to be advised on anything stupid I could have done, but after 50 years of charging batteries (99% successfully) I am not aware of anything I might have done wrong.

Appreciate any input and guidance.

Neil.

[misha]

Could be a shorted cell which was drawing a higher current.
10.5v is a total discharged battery since 11.9v means that battery is allready flat.
When you have a bad cell and discharged battery...as soon as you put it on charger it start to boil.
So....that might happened with your battery.

70% charge should be around 12.3-12.4v.

[abscate]

Neil - i had enough bad experiences with smart chargers that I only have one left, which I use to recover a drained battery over a day, then disconnect.

For maintenance, I stick with simple 500mA-1 A block chargers and just leave them hooked up.

[scot850]

I use a maintainer/charger that can run a 2A or 4A and has been used many times ok, as well as a regular charger I have had for many years (Schumacher). I had only used the 'intelligent' charger maybe 3-4 times at most in nearly 2 years.

As to misha's thoughts, it is of course possible that there was a bad cell, but I did check before charging with a hygrometer and all cells showed nearly the same charge status. Not to say it may have failed during charging.

Neil.

[jreed]

I also can report good luck using my Schumacher low current (6A) 12V charger a time or two to charge a battery that has been inadvertently run down by leaving a light on or a door open for a long time.
I also have had success identifying a failed battery with an inexpensive load tester I picked up from Harbor Freight. If you use it to test a battery that has a full or nearly full charge, it can help identify failing cells or intermittent internal connections. It basically applies a resistive load to the battery and indicates the voltage across the load -- like doing a voltage drop test. It's old school, non-electronic, but it has helped me be sure that a couple of batteries that I was able to fully charge but wouldn't start the car were indeed failing. It can be a helpful guide when you're not sure why your car won't crank even though the terminal voltage is 12.6V before cranking.

[scot850]

I have a load tester I bought from Princess Auto (The Harbor Freight of the North!). It tells me all the batteries I own are bad for load, but most batteries last through our winter just fine. Doesn't tell you which cell is failing but I use this and then a hygrometer to check the charge in each cell. Typically it will help identify a weak cell or low fluid level.

What I was looking for is a pulse charger which I had in Europe and recovered a few batteries for me a desulphating/regenerating charger if anyone can recommend one they have had luck with.

Thanks for replies,

Neil

[precopster]

On the channels I've viewed on battery revival they always charge at 0.7-1.0A over 1 or 2 days.

I bought an i Max B6AC LiPo cell charger which also has a Pb (lead) battery charge function and used it to charge our XC70s battery. You can set the current rate anywhere from 0.6A to 6A but I don't recommend rates above 1A if you're trying to revive a battery that has been left sitting. This charger has a built in timer and protection against over-voltage and over current. They're not easy to setup but work better than most of the other dedicated chargers on the market because they are designed for LiPo cells which require great accuracy.

It took about 3 days of charging at 700mA with a 10 hour break between charges to revive it. The battery was tested by a callout technician 2 years ago and deemed to be unredeemable. It still starts the car easily if not left over a week.

[scot850]

Thanks Mike. I'll have a look into the charger you mention. A quick look on line would suggest you must make up some leads to be able to charge a car battery with this unit?

Thanks,

Neil.

[precopster]

Hi Neil. I just screw a hose clamp to the battery as it's usually not in the car at the time. The supplied small alligator clips do the job. The great thing about these chargers is if they detect no current draw they immediately shut power off and call up an error so you dont really need to worry about the best clamping arrangement.

[scot850]

Good to know and thanks for the tips.

Neil.