Which pin is used as output for connecting load on spv1050 ? i need to connect load .

[TVard.1]

i am trying to charge li ion battery. the power should be available all the time , even if there is no harvesting in process.

#Spv1050​ 

[Peter BENSCH]

"...power should be available all the time..." do you mean power from the battery to the load?

Please have a look at AN4397, fig 4, where you can see the battery is connected to CN2.1 and CN2.2, which is the battery output of the harvester board. Your load is then probably connected in parallel to your battery.

As the datasheet, section 6.1 of the SPV1050 says the internal pass switch is just closed when the battery needs to be charged, it opens when the battery is fully charged or when there is no input power to the harvester. That pass transistor has an on-resistance of about 6...8 ohms, which is fine for the maximum battery charging current of 70mA.

Does it answer your question?

Good luck

/Peter

[TVard.1]

How to save battery from undervoltage.? If i connect load in parallel then battery may overdischarge.

[Peter BENSCH]

Correct. The battery must be protected against this, since the harvester as such cannot offer that protection, as the SPV1050 is only doing the charging stage.

Usually the load of the battery is providing this feature and gets disconnected when the battery voltage drops a certain value.

/Peter

[GAbi .1]

Hi Peter,

Regarding this topic, I thought that the load should be connected to an LDO in order to protect the battery from over discharge.

How can we protect the battery from over discharge (under the VUPV) if the battery and the load are not being connected to the evaluation board of the SPV1050 ? I didn't understand this point.

Could you please help me?

Thank you

Georgina

[Peter BENSCH]

Maybe my previous posts and the appnotes/datasheet were a bit misleading.

• Usually the battery is connected to pin VBATT (STEVAL-ISV020V1, CN2.1) and GND (CN2.4 or CN2.6)
• The load is connected in parallel to the battery
• The LDOs get their power internally from STORE and usually supply other electronic systems that are not directly part of the load.
• The limits (UVP, EOC) of the SPV1050 protect the battery from overcharging and over-discharging mainly by the LDOs - since the inputs of the LDOs are internally connected to STORE and the battery would be discharged more deeply than permitted.

This helps protect the battery from being over-discharged by the harvester and its LDOs. Of course, the load must check the undervoltage limits and switch itself off if necessary.

Does it answer your question?

/Peter

[GAbi .1]

Yes thank you for your explanation.

Just to make sure so when connecting the battery to the load, the voltage across the battery should be monitor (by the user) to open the switch between the battery and the load when the battery voltage reaches the Vuvp, right ?

Thank you for your help,

Georgina

[Peter BENSCH]

Absolutely.

However, it is up to the user application to either remove the load from the battery or shut down itself.

Good luck!

When your question is answered, please close this topic by choosing Select as Best.

/Peter

[RCarv.3]

Hi,

I am working with STEVAL-IS0V02V1 and I have a PV pannel and a battery connected with 3.3 V close to the maximum capacity.

When we don't have power supply on PV panel, shouldn't the battery voltage supply the system?

for example, shouldn't it have 1.8V and 3.3V in LDOs output as long as it has battery power?

Could you help me please?

Rui