How to charge a battery...

[rivermobster]

Unless you have one of those fancy chargers that let you pick:. AMG, Gel Cell, Standard, Deep cycle, this will get it done with no issues.

First, check it's open circuit voltage.

12.7 is fully charged battery. Stop here. You are done.

If it's less...

We have work to do.

 

[rivermobster]

If you have a small battery, start out with a 10amp charge. If you have a full size battery, go for 20ams or so.

If the voltage comes up a bit, you're on your way. If it shoots up to 15v or more, you have a battery with issues! I'd probably recommend just replace it.

This one is so far, looking good.

But it's not looking as good as I'd like it to, yet...

 

[rivermobster]

This is better. Ideally, I wanna see it charge around 14.5 volts or so.

If it gets closer to 15v, back that bitch up! You'll overheat it and boil all the acid out of it. This is bad. Very bad.

This battery is taking 40 amps and still staying low. That's the sign of a good battery. Phew.

Keep a close eye on it as the voltage creeps up. You can't let it get too high (as mentioned above).

 

[rivermobster]

Right now it's sitting at 13.2v

Seems about right for a battery that was that low. I'm going set a timer for 60 min or so and go grab a bite.

Let's see what it's at when I get back...

 

[Mandelon]

I've had a couple dead batteries that my charger thought were only 6V batteries. So the charger took em to 6 and shut off.

I think I ended up wiring it to a second battery to get the charger to keep going with it. Once it was up to 8, then the charger figured out it need to go to 12.

 

[Ziggy]

Just tried all the tricks on an Odessey AGM battery to no avail.
$187 with free shipping for a new one, just landed on the porch an hour ago.
In RDs aux battery/jumper thread I mentioned new cutoff and jumper studs I was installing.
I did a poor job keeping the old battery up because access was not easy, pure laziness......so the above mentioned installs are for simplification.

 

[rivermobster]

Now I'm happy. I'm going to keep a close eye on this, and make sure the voltage doesn't get too high.

 

[RiverDave]

Charging at 40 amps?

That's like the jumpstart mode on my little bullshit chargers.. LOL

We have an option of like 2 or 10 on my old school ones.

The new ones I bought are all electronic.. The "Genius" you hook it up and it will "recondition" the battery by taking it down and some weird pulse charge or some voodoo science I'm not familiar with. The other big electronic one I bought you hook it up select the type and it's off and running.

RD

 

[rivermobster]

Charging at 40 amps?

That's like the jumpstart mode on my little bullshit chargers.. LOL

We have an option of like 2 or 10 on my old school ones.

The new ones I bought are all electronic.. The "Genius" you hook it up and it will "recondition" the battery by taking it down and some weird pulse charge or some voodoo science I'm not familiar with. The other big electronic one I bought you hook it up select the type and it's off and running.

RD

The reality is, it's the voltage that truly matters. That's kinna why I started this thread. So you can see what's actually going on.

Yeah, the charger is in the 40 amp position, but is it really pushing that?? You'd have to have an amp meter to know.

What's important, to get a full charge, is a steady 14v level. Too much voltage, and the battery will fry. Too little, and it will most likely never Fully charge. Wanna guess what the charging voltage is on your car? 14.2 volts at ALL times. The alternator has to keep up with the AC, lights, stereo, and anything else you throw at it. It varies the amperage to keep up with the demand. A 100amp alternator is not always putting out 100amps at all times. And neither is a good battery charger.

The fully automatic good ones, like you have, where you just set the battery type are way cool. But not everyone has one of those. You probably paid good money for it.

Gimme a bit, and I'll throw and amp clamp on this deal...

 

[sirbob]

All I can say about this is a 750 trickle won’t get it done!

 

[rivermobster]

This is the perfect example of how things can go south Real quick!

I had to turn the charger off for a bit, cause I spilled some gas just a few feet from it. I just grabbed the cord and pulled the plug. I didn't touch anything else.

But when I plugged it back in, everything all went to hell! Over 15v? This battery is going to fry. See what happens when you don't use a volt meter, and pay attention to it? I would have destroyed a good battery, that was previously charging just fine...

 

[The Prisoner]

Where do you live? I want to come hear the boom!

 

[rivermobster]

So I backed down the charger to the 20amp position, and now I have the voltage I want.

I'm going to check the actual amp output next.

 

[rivermobster]

Where do you live? I want to come hear the boom!

https://rettsperformance.com/

Come by anytime.

 

[boatnam2]

Here is one for you big Joe, On my ez-go 36 volt cart I pulled the 6, 6 volt batteries and put in 3, 12 volt batteries. Worked great but my charger broke so I just stared hooking up 3 trickle chargers 1 to each battery. I'm not sure how it happened but one of the batteries all the sudden keep showing I had it hooked up battery backwards. Took about 2 more trips until I decided to take it back to orielly, gut calls me and said battery is good, maybe I revered polarity when I charged it. Go figure not it works fine.

 

[rivermobster]

Anybody wanna guess how many amps this charger is putting out at the moment, before I show the results?

Look at the last two pics I posted and then enter your guess!

@RiverDave

 

[rivermobster]

Here is one for you big Joe, On my ez-go 36 volt cart I pulled the 6, 6 volt batteries and put in 3, 12 volt batteries. Worked great but my charger broke so I just stared hooking up 3 trickle chargers 1 to each battery. I'm not sure how it happened but one of the batteries all the sudden keep showing I had it hooked up battery backwards. Took about 2 more trips until I decided to take it back to orielly, gut calls me and said battery is good, maybe I revered polarity when I charged it. Go figure not it works fine.

Before I say anything...

I want to see how the batteries and chargers were hooked up.

Just draw it on a piece of paper and take a pic.

 

[Go-Fly]

2 amps

 

[lbhsbz]

If you have a conventional battery with a resting voltage of over 12V that won’t crank a vehicle and is able to draw 40A from a charger, you have bad battery.

It might work again, but it won’t work as well as a new battery.

I test batteries with a carbon pile load tester, an electronic resistance/impedance tester, and a hydrometer...questionable batteries will always fail one, even after a solid charging.

 

[Carlson-jet]

I'm going with 6 amps

 

[Mandelon]

Just an FYI, the electric spark happens when you remove a plug from an outlet. Doing so may not always be the safest action.

 

[rivermobster]

If you have a conventional battery with a resting voltage of over 12V that won’t crank a vehicle and is able to draw 40A from a charger, you have bad battery.

It might work again, but it won’t work as well as a new battery.

I test batteries with a carbon pile load tester, an electronic resistance/impedance tester, and a hydrometer...questionable batteries will always fail one, even after a solid charging.

A battery showing 12v on a volt meter is pretty much dead. It might crank for a little while, but if the engine isnt gonna start right way, a battery showing 12v isnt gonna crank for too long. It should be charged before it is used or tested.

Most people don't have high amp gauges and load testers laying around their garage. But most everyone on here probably does have a battery

charger and a volt meter. I'm just handing out tips for how to best use them.

I cheap hydrometer is handy to have too. I was gonna get to that later...

Just an FYI, the electric spark happens when you remove a plug from an outlet. Doing so may not always be the safest action.

Excellent point!

In our shop, the outlets are all mounted at least 4ft off the ground. The charger was basically on the ground, and right next to the spill. Pulling the plug was the safest option in this case, since the spill had only just happened seconds before I pulled it.

Great observation. :thumbup:

 

[Carlson-jet]

All good things to be aware of. I never had to clean up the mess of a battery exploding until about 2 years ago. Well worth the effort to keep an eye on things when charging with anything over a few amps.
I wasn't charging the battery, it was my boss. I just got to clean up the mess.

 

[rivermobster]

Ok, I'm going home...

The correct answer is................................

1.1 amps (with the charger on the 20amp setting.

I'm thinking tomorrow, I'll have a battery sitting at about 12.5 volts. Should be close to being completely charged. I hope.

And no, I'm NOT going to let it charge overnight. Im turning the charger off now.

 

[Carlson-jet]

Ok, I'm going home...

The correct answer is................................

1.1 amps (with the charger on the 20amp setting.

I'm thinking tomorrow, I'll have a battery sitting at about 12.5 volts. Should be close to being completely charged. I hope.

And no, I'm NOT going to let it charge overnight. Im turning the charger off now.

View attachment 818865 View attachment 818866

Quitter.

 

[lbhsbz]

I'm proud of you for bringing out the amp clamp...

My Dad's motorhome had a strange battery in it last year. Clamps were clean and tight. Resting voltage was less than 11.5 (I don't recall the exact number, but it was at least that low). No signs of anything strange, I just decided while he brought it over to the house so I could address a few other issues before he went on his annual 2 week long trip, I'd test all the batteries.

Now, keep in mind, my Dad is a cheap old man who uses whatever batteries he can find. The coach has one starting battery, one house battery, and one generator battery. Typically, the house and generator battery are linked together while keeping the starting battery isolated. There is a "booster" switch which can tie them all together for starting if need be, although I fail to see the point in that. The house battery is typically the battery that he uses in the boat all summer, then transfers to the MH for the winter. The house and genny battery tested good, while the starting battery, at 11.5V, PASSED the carbon pile load test...dropping only to 10V under load, but only recovering to 11.4 or so. Failed the hydrometer and resistance test miserably. It would accept all the amps you wanted to give it, but after removing the surface charge, would be back at 11.5V. That's what reinforced my multiple testing methods. I'm not sure how long that battery would have worked, but clearly something was wrong with it. On the middle of a lake or on a road trip, questionable batteries are the last thing I want to deal with.

If the battery is too dead to start the vehicle, that level of discharge has very likely degraded the battery such that it will never be in "good" condition again...best to just throw down $100 or so on a good quality new one, take care of it, and avoid any battery related headaches for the next 3-5 years.

 

[rrrr]

Here is one for you big Joe, On my ez-go 36 volt cart I pulled the 6, 6 volt batteries and put in 3, 12 volt batteries. Worked great but my charger broke so I just stared hooking up 3 trickle chargers 1 to each battery. I'm not sure how it happened but one of the batteries all the sudden keep showing I had it hooked up battery backwards. Took about 2 more trips until I decided to take it back to orielly, gut calls me and said battery is good, maybe I revered polarity when I charged it. Go figure not it works fine.

You're going to be buying batteries sooner than you'd like unless you get a real charger.

 

[Carlson-jet]

I'm proud of you for bringing out the amp clamp...

My Dad's motorhome had a strange battery in it last year. Clamps were clean and tight. Resting voltage was less than 11.5 (I don't recall the exact number, but it was at least that low). No signs of anything strange, I just decided while he brought it over to the house so I could address a few other issues before he went on his annual 2 week long trip, I'd test all the batteries.

Now, keep in mind, my Dad is a cheap old man who uses whatever batteries he can find. The coach has one starting battery, one house battery, and one generator battery. Typically, the house and generator battery are linked together while keeping the starting battery isolated. There is a "booster" switch which can tie them all together for starting if need be, although I fail to see the point in that. The house battery is typically the battery that he uses in the boat all summer, then transfers to the MH for the winter. The house and genny battery tested good, while the starting battery, at 11.5V, PASSED the carbon pile load test...dropping only to 10V under load, but only recovering to 11.4 or so. Failed the hydrometer and resistance test miserably. It would accept all the amps you wanted to give it, but after removing the surface charge, would be back at 11.5V. That's what reinforced my multiple testing methods. I'm not sure how long that battery would have worked, but clearly something was wrong with it. On the middle of a lake or on a road trip, questionable batteries are the last thing I want to deal with.

If the battery is too dead to start the vehicle, that level of discharge has very likely degraded the battery such that it will never be in "good" condition again...best to just throw down $100 or so on a good quality new one, take care of it, and avoid any battery related headaches for the next 3-5 years.

Dead batteries play hell on all the rest of the electrical system. Sometimes a battery change is cheaper but I like how pops conserves, not the worst attitude.

 

[lbhsbz]

Dead batteries play hell on all the rest of the electrical system. Sometimes a battery change is cheaper but I like how pops conserves, not the worst attitude.

It is when I spend 2 hours figuring out why shit doesn't work...only to find 3 batteries of different vintages/CCA ratings/etc...

All are only as good as the worst one in the system

 

[Carlson-jet]

It is when I spend 2 hours figuring out why shit doesn't work...only to find 3 batteries of different vintages/CCA ratings/etc...

All are only as good as the worst one in the system

He's your Dad. I sure miss mine.

 

[C-2]

Great post Joe, it's a keeper. Thanks!

 

[lbhsbz]

He's your Dad. I sure miss mine.

I've been thinking about what you said for the last 10 minutes. It's interesting how for so many years he would beat in into me how to do things right while I would typically halfass everything when I was younger, and now I'm beating into him how to do things right as he attempts to halfass everything as he gets older.

Circle of life I suppose. I embrace every minute of it. Thanks for reminding me to do so.

 

[rivermobster]

I'm proud of you for bringing out the amp clamp...

Me thinks you've had way more to drink than I have tonight!

 

[rivermobster]

Great post Joe, it's a keeper. Thanks!

There will be more tomorrow. Stay tuned!

 

[Carlson-jet]

I've been thinking about what you said for the last 10 minutes. It's interesting how for so many years he would beat in into me how to do things right while I would typically halfass everything when I was younger, and now I'm beating into him how to do things right as he attempts to halfass everything as he gets older.

Circle of life I suppose. I embrace every minute of it. Thanks for reminding me to do so.

I do hope you thought positive of the reply. I also hope your Pops is out there with you while you make things right and are having good conversation. It is a circle for some of us who were lucky enough to even get that chance, some on here didn't.

Back to the art of Battery charging 101.12

 

[lbhsbz]

Me thinks you've had way more to drink than I have tonight!

While that may very well be the case...I had the low amp probe and the scope out the other day dialing in the charge rate on some shitty NiMH RC car batteries for the kid...3C on the nose...had a couple temperature probes on channel 2 and 3. It's helpful to see what's happening rather than trusting the dial.

Plus, I get to play with it longer while he's inside doing his homework.

ME: learn the math and do your homework
KID: I'll never need to know any of this stuff
ME: drives kid's RC car around for 30 minutes on one battery
KID: How come the battery lasts so long when you drive it
ME: Because I learned math and did my homework

 

[rivermobster]

While that may very well be the case...I had the low amp probe and the scope out the other day dialing in the charge rate on some shitty NiMH RC car batteries for the kid...3C on the nose. It's helpful to see what's happening rather than trusting the dial.

BNAG!

Thank you for bringing that up!

I was gonna talk about that. The ol RC car battery trick. You push the voltage up to right where it starts to fall, and cut it off real quick. Anyone that does RC cars knows about this. It's the best way to keep em max charged.

I'll do the same thing with a car battery, sorta...

Start off with a lower amp charge, push it higher once the battery gets up to 13v, and then when the voltage gets close to 15v, back it down till it settles in around 14 and change. Then I'll let it sit there for awhile.

Today, we ended up with a very low charge rate (1.1 amps) and a 14.5 steady voltage.

That's what will get a battery back to Full charge. A nice steady low amp charge at 14+v. It doesn't hurt the battery longivity that way one bit.

Interesting you bringing that up!

Tomorrow we will see what we got.

 

[Carlson-jet]

While that may very well be the case...I had the low amp probe and the scope out the other day dialing in the charge rate on some shitty NiMH RC car batteries for the kid...3C on the nose...had a couple temperature probes on channel 2 and 3. It's helpful to see what's happening rather than trusting the dial.

Plus, I get to play with it longer while he's inside doing his homework.

ME: learn the math and do your homework
KID: I'll never need to know any of this stuff
ME: drives kid's RC car around for 30 minutes on one battery
KID: How come the battery lasts so long when you drive it
ME: Because I learned math and did my homework

This is battery charging to the extreme but i like it. Temp probes? Nice. I'm weird like that too just because it's fun and I have them.

 

[rrrr]

This is battery charging to the extreme but i like it. Temp probes? Nice. I'm weird like that too just because it's fun and I have them.

I visited an Exide battery factory back when I was installing 192 battery strings of their huge 2V wet cells in data centers for UPS systems. The largest were roughly 2' X 2' X 2.5' in size and weighed around 300 lbs per cell.

Once the batteries were filled with the several gallons of electrolyte required, they were placed by the dozens in long troughs of circulating chilled water for the 2.65 volts per cell initializing charge. That is the equivalent of 15.9 volts on a 12 volt battery, and it created a huge amount of heat. Each battery had a temperature probe inserted in it during the charge cycle.

This is what they looked like installed:

 

[lbhsbz]

I do hope you thought positive of the reply. I also hope your Pops is out there with you while you make things right and are having good conversation. It is a circle for some of us who were lucky enough to even get that chance, some on here didn't.

Back to the art of Battery charging 101.12

I'm sorry that you lost your Dad early...I'm very fortunate that I didn't.

This is battery charging to the extreme but i like it. Temp probes? Nice. I'm weird like that too just because it's fun and I have them.

I grew up with a Championship edition RC10 (non-stealth transmission) and Sanyo 1200mAh 6 cells. Mom used to ask about the extension cord across the kitchen floor and up the freezer door. Had to make the best of what I had to work with.

Wanna have some real fun, check out sparkfun.com and get a whole bunch of stupid sensors, then pick up a Hantek 1008 8channel scope for $100. You can give yourself an EKG with less than $50 worth of parts I think.

 

[Carlson-jet]

I visited an Exide battery factory back when I was installing 192 battery strings of their huge 2V wet cells in data centers for UPS systems. The largest were roughly 2' X 2' X 2.5' in size and weighed around 300 lbs per cell.

Once the batteries were filled with the several gallons of electrolyte required, they were placed by the dozens in long troughs of circulating chilled water for the 2.65 volts per cell initializing charge. That is the equivalent of 15.9 volts on a 12 volt battery, and it created a huge amount of heat. Each battery had a temperature probe inserted in it during the charge cycle.

This is what they looked like installed:

That is one heck of a UPS system, would be cool to see the charger.

 

[rrrr]

I'll detail the fun a bit, using a 500 kVA system as an example. They were fed with a 480 volt three phase 1000 amp breaker.

The rectifier system in UPSs of that vintage had two front end transformers connected to the incoming three phase feeder, one with a delta output, and one with a wye output. This provided two sources for rectification with a 30° phase shift, which then provided a 12 pulse per hertz (720 pulses a second) 435 volt rectified DC voltage. The DC bus had filters consisting of dozens of soda can sized 450 VDC 35 mfd capacitors to smooth out the ripple from the rectifier pulses, making the DC output stable.

The rectifier fed the inverter system, which turned the DC voltage back into AC voltage and thus the UPS output. It also supplied DC current to the batteries to maintain a float charge on them. When the incoming AC power failed, the rectifier stopped, and the batteries supplied the inverter. When the power returned, the rectifier again provided power to the inverter, plus current to charge the battery. If the battery had been severely discharged, the recharge current would surpass 300 amps at 435 volts DC.

Now big UPSs work in a completely different manner, and are much more efficient when operating with incoming power. They still use energy when recharging the battery, but with a diesel generator backup the discharge time is minimal, just a few seconds.

The old units wasted literally tens of thousands of dollars in power annually compared to modern units. A data center with five or six 500 kVA UPSs would easily blow through $500K of wasted energy annually due to inefficiencies.

The difference is microprocessor controls. The old ones used what was called TTL, transistor to transistor logic. It was an analog logic that used gates like less than, greater than, or, not or, etc. to control what was going on. The UPS would have like 10 printed circuit boards, each the size of an iPad. Primitive stuff compared to today. In fact, that's why appliances like washers and dryers or A/C units have variable speed motors now, electronic variable frequency inverter control. They're cheap and efficient.

 

[Carlson-jet]

Why would a battery factory need that type of date retention back up?

 

[rivermobster]

Ok so...

Back to the real world?

I said yesterday, this battery would probably be around 12.5 this morning.

Even a blind squirrel gets a nut once in awhile!

 

[rrrr]

Why would a battery factory need that type of date retention back up?

It didn't. I was invited on a tour of the factory because I was buying millions of dollars of batteries from them. The batteries went into data centers. Sorry for the confusion.

 

[rivermobster]

So why did I wait until the next day to check it again?

Batteries are nothing but a chemical reaction, that is producing electricity. The reaction time is basically slow.

Right after pulling the charger off, it would have read around 13.5v. Good right? You think it's fully charged, throw it in the boat and go boating! But after you've run the stereo for awhile, it's dead again.

Bad battery? Or was it really not fully charged?

The 13.5 is what's called a "surface charge". Another chemistry thing. You can pull it off by putting a load on it , and testing again, but the best thing to do is to wait.

The 12.45 it shows this morning is the true battery charge. It needs to spend more time with the charger.

And since we know it was charging at 14.5v with only 1amp yesterday, I'm gonna put the charger on the 2amp settings, and let it charge as much as I can today.

Hopefully tomorrow I'll have a full charge.

P.S. This is a red top optima battery. They take forever to get to a full charge!!!

 

[530RL]

Excellent information and way above my ADD.

I just plug this thing on the car to this thing on the ground and all is good.

Thankfully engineers plan for people like me.

 

[rivermobster]

It didn't spend Anytime on the charger today. Although I did diagnose a draw on it this morning. The customer will be stoked about that!

I'm going to keep trying to get the static voltage to 12.7

Courious to see how long it will take.

 

[Carlson-jet]

It didn't spend Anytime on the charger today. Although I did diagnose a draw on it this morning. The customer will be stoked about that!

I'm going to keep trying to get the static voltage to 12.7

Curious to see how long it will take.

That would be a cool thread figuring that out or adding it here. Not the easiest task sometimes. I don't work on daily drivers in the wintertime around here much and have paid well to have someone think they fixed the issue only to come out to a dead battery at some point.

 

[rivermobster]

That would be a cool thread figuring that out or adding it here. Not the easiest task sometimes. I don't work on daily drivers in the wintertime around here much and have paid well to have someone think they fixed the issue only to come out to a dead battery at some point.

Pretty simple really...

This is a street rod I've been working on, so there wasn't a lot to check!

I'll show you how I did it when I have time. I have to get a buggy going today...