Does an mppt work with Li-Po Battery?

Hi, we have an autonomous boat. We would like to mount some solar panel to charge the lipo battery during battery is in use. Can we do that? I saw that mppt are in use for LiFePo4 battery but we dont have it.

Well, that would be a question best asked to someone in the solar industry.
But having said that I do have some experience in that field.
Yes, there are solar charge regulators out there (including MPPT) that are suitable for LiPo batteries. It may not be a balanced charge system but still suitable for LiPo batteries.

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Sir how we can do that? All 4 solar panel should be connected series or parallel? Do we need only mppt or we should also purchase a bms?

If you pick a suitable regulator you might be able to have up to 200V of input voltage. So certainly possible having all 4 solar panels in series. This is usually the preferred way as this allows energy harvest even during cloudy / low light conditions.

You don’t need an extra BMS if you select a suitable charger. Here is one example but I believe this one may not be suitable for LiPo batteries.

or (also may need to double check regarding LiPo batteries)

Here is a comparison list:

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Sir those items doesn’t available in my country. Ordering from another country will take much time that we have. We have 8000mAh,25C,3S1P Li-Po battery, 12V,7A rechargable lead acid battery and 4 pieces solar panel 50W-12V solar panels. Can we built a power pack for 8000mah lipo charging with imax charger?

a) imax charger requires fairly constant supply voltage(11-18V) so you would need a voltage regulator between your solar panels and the imax charger.
b) Whilst the imax charger is a very versatile charger, it requires manual starting each charging cycle by pushing the start button and confirming the selected options.

My understanding is you would like a system that automatically charges the batteries whenever needed. (battery getting low). The imax charger can not do this.

As mentioned earlier, I would talk to a local solar system supplier and see what chargers are available in your country that are suitable for your intended use.

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Sir ı just want to extend the flying time of my autonomous boat. With the help of 8000 mah, it is really hard to do.

As I said in the PM, I have no hands on experience with solar power.
Perhaps you could try this:
Put an ideal diode between the lipo an the power module and connect the solar panels in parallel to the input of the power module (behind the ideal diode). This way the solar panels will not charge the lipo, but the solar panels will help to power the motors, if the sun is shining. The only additional hardware you would need is an ideal diode.

I would suggest another diode on the solar panel side of it as quality panels supposed to have one build in but others don’t.
But whilst that helps with extending running times it won’t charge the Lipo battery.

  • A note on the side: LiPo batteries require a form of pulse charging. So never connect a regular charger like a Lead Acid battery charger to a LiPo battery!
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So, do we need another kind of battery such as lifepo4 battery instead of lipo battery? If there is no way to charge the lipo battery while it is in use to extend the duration by using solar. It looks like we can not use also lead acid battery for the pixhawk,right?

Your original question was for charging the LiPo battery.

If you want to use both batteries you can possibly use them both providing you use diodes on both batteries and the solar panels. But this will not charge the batteries.

For charging:
You could use one basic charger for Lead Acid Battery and another charger for the LiPo battery. Then depending on the version of Pixhawk you have you can also possibly use both batteries to power the Pixhawk. In that way you will have some redundancy build in.

I would suggest search online in your country for appropriate chargers as I can not do this for you. - Have already provided a list of suitable chargers.