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Lead-acid batteries removed

A project log for A 110 kWh Powerbucket

The lead-acid batteries of my off-grid solar system are dead. I will replace them by a 18650 batteries stack housed in a big wooden box.

michel-kuenemannMichel Kuenemann 09/28/2016 at 19:272 Comments

Tonight I have removed the 8 lead-acid batteries out of their box:

Before start:

Removal in progress:

The box is empty now:

The pieces of wood raised the batteries a bit. The green part is a liner that would have avoided the catastrophic consequences of a battery leak. Lead-acid batteries contain sulfuric acid...

Just for fun, I have placed two new Li Ion modules - These two small modules weighing about 6 Kg store more energy than a single lead-acid battery weighing 60 Kg.

Close up on the modules:

The long copper bar serves for attaching the future modules coming in parallel with the first one.

Discussions

Michel Kuenemann wrote 04/03/2017 at 20:21 point

I guess I killed my batteries because during the first months (entry into service took place in autumn 2013) I did not manage to fully charge them regularly and they stayed in a partial charge state during a long time. I think that this was the cause of sulfation.  Partial charge state is known to be very bad for lead acid batteries.

The nominal energy of the pack was 48 X 440 = 21 kWh. I used only 6 kWh (less than 30 %) each cycle. 

What kind of batteries have you installed ? Do they last ?

Thank you - Michel

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Luke wrote 04/03/2017 at 17:47 point

wow its amazing that your batteries died in just two years.

how deep were you discharging them?

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