Solar charging batteries

[redneck joe]

If the voltage numbers are correct, and you assume that the battery has no more than 20% charge after 4 days based on the voltage, then it looks like the charger is running at about 100 milliamps (basically float charging).

That sounds like something but dont know what float cc harging is.

 

[bruceb58]

It is a 20 amp. If you have not read the whole thread these were left unattended for a couple years and when I started this a few days ago this one read less than 1v. Im assuming, since I don't know sh.t about them that it is waking g up from the dead and that may take longer.

Iirc 11.6 is the magic number to know if there is a chance at resurrection,

Your battery is toast. If you let them sit that long, one or more of the 4 cells self discharged lower than minimal cell voltage which is around 2.5V. There is likely no recovery.

 

[cyclops222]

I still have 10 year old B & D power tool LIFEPO4 packs that hold voltage forever. And recharge in about 15 minutes.
Crap batteries die quickly. For different reasons.
A cheap BMS system WILL / DOES constantly run down the battery.

 

[redneck joe]

Hmm... 11.39 just now.

 

[tpenfield]

Remove the charger and see if the voltage holds or goes down. There may be some new batteries in your future,

 

[redneck joe]

Oh I am very confident that there will be. This is just a no cost fun thing to do.

I did buy a new starting battery and moved the old deep cycle up front for the trolling motor. Used prob hour of running g tim the other day so that will suffice until it goes as well. It is a 2018 with very little use but also no charging for a couple years as well.

 

[cyclops222]

Have you checked the water level in the batteries each year? Any part of the lead plates allowed to dry out. Will permanently reduce the capacity of the battery.
50 % of cell allowed to dry out to air. Is 50 % capacity lost forever by normal people.

 

[airshot]

Oh I am very confident that there will be. This is just a no cost fun thing to do.

I did buy a new starting battery and moved the old deep cycle up front for the trolling motor. Used prob hour of running g tim the other day so that will suffice until it goes as well. It is a 2018 with very little use but also no charging for a couple years as well.

I understand, I often find myself working on little projects that have little hope of getting fixed. On the occasion when one does work out...WoHoo, it sure makes you feel good !!

 

[redneck joe]

Have you checked the water level in the batteries each year?

That i did.

 

[bruceb58]

I still have 10 year old B & D power tool LIFEPO4 packs that hold voltage forever. And recharge in about 15 minutes.
Crap batteries die quickly. For different reasons.
A cheap BMS system WILL / DOES constantly run down the battery.

Batteries for power tools including Dewalt and Black and Decker use Lithium Nickel Manganese Cobalt Oxide batteries. They do not use LiFePO4.

A BMS uses around 1mA unless it's bluetooth(if it has that feature) is active. Even with a small drain like that, it will draw down a 100AH battery in a little more than a year.

 

[redneck joe]

11.47 as of this morning. Going to give it until tomorrow to hit the magical 11.6 number.

 

[redneck joe]

11.55 when I got home today, getting excited....

 

[airshot]

Batteries for power tools including Dewalt and Black and Decker use Lithium Nickel Manganese Cobalt Oxide batteries. They do not use LiFePO4.

A BMS uses around 1mA unless it's bluetooth(if it has that feature) is active. Even with a small drain like that, it will draw down a 100AH battery in a little more than a year.

Scary thought that people would go a full year without checking their
battery !! This is where a maintainer for LA batteries comes in. My LifePo4 battery company recommends the battery get a charge/ discharge every three months in storage. Maintenance is everything, no matter what !

 

[redneck joe]

Scary thought that people would go a full year without checking their
battery !! This is where a maintainer for LA batteries comes in. My LifePo4 battery company recommends the battery get a charge/ discharge every three months in storage. Maintenance is everything, no matter what !

I was treating my colon cancer. Life happens.

 

[Grub54891]

I was treating my colon cancer. Life happens.

Me to. Life gets priority at times. So far I’m doing fine, tests coming back clear. We can only hope that it stays this way.
actually working part time at the marina hauling boats this time of year. Check out: washburnmarina.com tomorrow we put the Madeline island ferry boat back in the water with the 150 ton travelift.

 

[cyclops222]

My B & D packs are VERY OLD model years. They are LIFEPO4 chemistry. I have run the cells in the B & D vacuum cleaner down to 2 %. They are still charging up to 90 % and running strong.
I was able to bu the last of the LIFEPO4 battery packs when they discontinued the LIFEPO4 chemistry.

 

[redneck joe]

Check out: washburnmarina.com tomorrow we put the Madeline island ferry boat back in the water with the 150 ton travelift.

Roughly what time is the splash?

 

[Grub54891]

Roughly what time is the splash?

I was told early afternoon. It takes about an hour by the time we get set up, get it lifted and driven over to the liftwell. It’s parked about 250 feet from the well. We will see how the day goes!
the guys will be doing other services on the boats in the morning I’m told.

 

[cyclops222]

Good post. I have not checked any of the many of the B & D batteries in decades. Will do it today.

 

[bruceb58]

My B & D packs are VERY OLD model years. They are LIFEPO4 chemistry. I have run the cells in the B & D vacuum cleaner down to 2 %. They are still charging up to 90 % and running strong.
I was able to bu the last of the LIFEPO4 battery packs when they discontinued the LIFEPO4 chemistry.

They have NEVER been LiFePO4. Before Lithium NMC, they we NiMH