My wakey wakey machine

[Mike Jordan]

I got an old charger out of my grandfathers barn over 20 years ago. He hadn't been in the barn much in the 20 years before that. So no telling how old this thing is. But the lack of built in "safety" is the greatest thing ever.

I have brought countless very low voltage batts back to life. My specialty was AGM. I got dozens of "bad" Optima batts from the auto parts stores and created $250 batts for the cost of a core charge. Now I can't get them to sell the batts to me any longer.

It also brought my Valence to life when I bought them. No LFP, hobby, or modern automotive charger I have would charge them at all, due to very low voltage. This thing wakes them up

I had these batts in a project for a year. Then I built some other batts, and took these out in about June of last year. So now, 9 months later I have another project for them. I had a BT batt monitor on these I forgot about. And they were at about 3.5v when I decided to use them again.

So I broke out the wakey wakey machine to wake them up. I boost the batts to 11.5/12v (just depends on how I catch them when I go back to check). And then put them on the hobby charger to finish out. Good as gold... or maybe lime green

 

[snoobler]

Following re-charging, how many times did you test the batteries to assess that they met either their C20 rating or their RC?

In most cases restoring their ability to hold a charge (voltage), is trivial. Restoring them to anything near their rated capacity is another matter altogether.

Another option with hobby chargers is to simply use the NiMH or NiCd profile and set to a low current.

 

[Mike Jordan]

Following re-charging, how many times did you test the batteries to assess that they met either their C20 rating or their RC?

Dozens of times. They have run my kayak for 100s of miles. I run an 80ah pair at about 60ah of use most trips. I've pulled 75-77ah out of them several times to bms shut off. Valence batts are bullet proof. Hospital quality, they have to be

 

[Gazoo]

It also brought my Valence to life when I bought them. No LFP, hobby, or modern automotive charger I have would charge them at all, due to very low voltage. This thing wakes them up

I also have 2 Valence RT batteries in parallel. The second one I ordered was DOA. I used a wall wart to wake it up.

My capacity is better than 75ah's when run down to 11.5 volts. I have never run them down until the BMS cuts off. These are awesome batteries. I always wondered if the magnesium mixed in with the chemistry does something to help prevent aging.

 

[snoobler]

By saying C20 or RC, I thought you would have understood I wasn't talking about the Valence as those don't have either rating.

I was talking about all of those $250 batts.

 

[Mike Jordan]

By saying C20 or RC, I thought you would have understood I wasn't talking about the Valence as those don't have either rating.

I was talking about all of those $250 batts.

Clueless on your code. But my Optimas run forever after rehab. Another batt you can't kill. (folks do put them to sleep, I wake them up) I have them in my ski boat and cars. I have one in my Jeep that is not a daily driver. So it sits for periods. Then it has to do long winch pulls. So probably the worse abuse that you can do to a batt. But hadn't quit yet

 

[Bob B]

Dozens of times. They have run my kayak for 100s of miles. I run an 80ah pair at about 60ah of use most trips. I've pulled 75-77ah out of them several times to bms shut off. Valence batts are bullet proof. Hospital quality, they have to be

View attachment 34466

Curious what motor that is?

 

[Mike Jordan]

Curious what motor that is?

That is a Watersnake 24lb thrust with a whollotta DIY. I removed the factory head and controls. The paddle flag sticker box on the shaft, is a Lowes LNB electrical box, that houses a remote controlled ESC

Then I got a rock crawler remote control, and removed everything that didn't look like it belongs on a kayak, and put it in a cell phone Outterbox for remote speed control

 

[Bob B]

That is a Watersnake 24lb thrust with a whollotta DIY. I removed the factory head and controls. The paddle flag sticker box on the shaft, is a Lowes LNB electrical box, that houses a remote controlled ESC

Then I got a rock crawler remote control, and removed everything that didn't look like it belongs on a kayak, and put it in a cell phone Outterbox for remote speed control

View attachment 34513

Wow .... Lotta DIY there.

 

[snoobler]

C20 is the 20 hour Ah capacity rating. RC is the reserve capacity - the number of minutes a battery can deliver 25A above 10.5V.

Many batteries will perform fine at low states of health. Restoring them to the point that they hold voltage may be perfectly fine, but it's not an indication of health.

Optima is garbage - just like every other Johnson Controls product made in Mexico. I have pulled dozens of failed Optimas from very light duty applications just after their warranty has expired with Yuasa products lasting 2X as long and in some cases up to 10 years. The mark-up is absurd. Yes, they used to be a premium brand and deserved praise, but the only thing premium about them these days is their price.

Next time you engage in this exercise, get a cheap modified sine wave inverter and run a 300W test (about 25A). See how your results compare to the RC rating.

 

[Mike Jordan]

C20 is the 20 hour Ah capacity rating. RC is the reserve capacity - the number of minutes a battery can deliver 25A above 10.5V.

Many batteries will perform fine at low states of health. Restoring them to the point that they hold voltage may be perfectly fine, but it's not an indication of health.

Optima is garbage - just like every other Johnson Controls product made in Mexico. I have pulled dozens of failed Optimas from very light duty applications just after their warranty has expired with Yuasa products lasting 2X as long and in some cases up to 10 years. The mark-up is absurd. Yes, they used to be a premium brand and deserved praise, but the only thing premium about them these days is their price.

Next time you engage in this exercise, get a cheap modified sine wave inverter and run a 300W test (about 25A). See how your results compare to the RC rating.

That "garbage' has never let me down. Try to winch multiple Jeeps in a row out of a mud hole, or up and unclimbable hill. You will certainly find a garbage batt in a hurry. My somebody elses "dead" Optima has done that for years

 

[snoobler]

I'm not exaggerating when I say "dozens." When you pay a premium for a battery, and it shows no better track record than all the other batteries of its class made by Johnson Controls in Mexico, it's "garbage." Automotive lead-acid batteries manufactured in the last 5-10 years, particularly those in Mexico, have taken a big nosedive in quality. Optima was no exception.

You provide subjective results. "Works for me" isn't scientific. Batteries held in float and used only occasionally may perform just fine even if at a very low state of health. Objective results have more meaning. When you demonstrate that you're restoring a battery to some % of its ratings, that's more meaningful. An Optima at 30%, which may function fine for you, isn't a $250 battery. It's what? $80?

AGM batteries don't "go to sleep." They are discharged below the threshold the typical 12V charger can charge them. When this happens, they sustain major damage and permanent hard sulfation that can't be fixed via any means. There's no need to use some old crusty charger to "wake them up." Simply paralleling them to another battery and charging them with a regular charger accomplishes the same thing.

I'm glad that everything has worked out for you. Your experience is atypical. There's no magic at work here. Just a lot of luck on your part.

 

[Mike Jordan]

I'm not exaggerating when I say "dozens." When you pay a premium for a battery, and it shows no better track record than all the other batteries of its class made by Johnson Controls in Mexico, it's "garbage." Automotive lead-acid batteries manufactured in the last 5-10 years, particularly those in Mexico, have taken a big nosedive in quality. Optima was no exception.

You provide subjective results. "Works for me" isn't scientific. Batteries held in float and used only occasionally may perform just fine even if at a very low state of health. Objective results have more meaning. When you demonstrate that you're restoring a battery to some % of its ratings, that's more meaningful. An Optima at 30%, which may function fine for you, isn't a $250 battery. It's what? $80?

AGM batteries don't "go to sleep." They are discharged below the threshold the typical 12V charger can charge them. When this happens, they sustain major damage and permanent hard sulfation that can't be fixed via any means. There's no need to use some old crusty charger to "wake them up." Simply paralleling them to another battery and charging them with a regular charger accomplishes the same thing.

I'm glad that everything has worked out for you. Your experience is atypical. There's no magic at work here. Just a lot of luck on your part.

I understand the concept. AGM do not literally sleep. That is hyperbole for effect. But a modern batt charger will not charge a dead low voltage batt. The protections will not even let it start. Look on Youtube, there are 100s of vids that will show you how to do it. Some the same as my method, others different. My decades old blaster, has no low voltage protection. It gets the voltage up, to let the modern charger take over.

All of my Jeepin boatin kayakin buddies all have some of my other peoples dead batts too. I have only failed waking up a couple, out of dozens. Don't be jealous. I wouldn't turn you down if you brought me one to revive