First Power On

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 11/27/2016 at 13:490 Comments

The first power on occured at 9 AM on Novembre, 26th.

The "old" lead-acid BMS was adapted to accomodate the voltages and thresholds of the lithium battery.

I installed a temporary desk in order to perform the necessary changes in the BMS software:

Monitoring the voltage with my DMM. The Nexus 7 tablet on the right displays the system real time status:

The weather was very dull yesterday. The sun gave bearly 1 KWh of energy on the whole day:

Charging of the battery started approximately at 11 AM (when the yellow area turns green). The first tests show that the modules are very well naturally balanced and behave very well under load (minimal voltage drop under heavy load). The batteries are currently at approx 50% state of charge.

In depth electrical test will be performed later.

See the real time curve

The weather should be much sunnier tomorrow. This will allow a full charge of the stack.