MPPT Boost/ or Buck Controller that will Charge Hobby Lipo Batteries ?

[ScooterMan101]

After years of thinking about it I am finally going to get a panel to put on a trailer and charge spare battery packs for longer trips and for the fun of it .
However
The Light Weight Flexible Panel I am getting has a output voltage of between a 3s and 4s pack . ( I want to charge 4s packs on up to possibly 6s but for now a 4s pack to run the DC to DC Lipo Charger )

What Small , lightweight , affordable MPPT controllers have you found , and/or what has worked for you ?

 

[dogman dan]

I just have a 12v charger, which is on my trailers house batteries. So with this in the yard, I'm solar charging the house batteries, and then running a 12v powered lipo charger off that. I have this panel out there keeping a big lead battery full, so I just tap that to charge my lipos now.

Not what you are doing though, but its turning out to be a convenient way to green charge my lipos.

You might be able to do the same type of thing, but by carrying a small lead battery, which would solar charge to 14v using a very cheap 10 amps MPPT, and then power up a lipo charger off the lead. Assuming you start with a 100w flex panel, you'd be able to run your RC charger at about 75w without the charger pulling down the voltage enough to stop charging. The 12v battery not so much to store a charge in, but to provide a steady voltage to the RC charger.

Lifepo4 would work better, in 4s, for your 12-14v pack btw.

 

[ScooterMan101]

Dan,

Well I did get the panel for two reasons , 1 for in the future when I can move out of the apartment complex to a better place where I can then have a few panels , running as much of the house usage as possible off them.

But for For right now I will be pulling the 160 watt ( probably 140 watts output in real outdoors conditions ) on a trailer that is being pulled by the bicycle.
And as such I must get the lightest weight budget small battery that will work with such a small 10 amp PWM controller you speak of.

SLA 12 volt batteries are heavy , however how small of a battery in amp hours do you think will work , just enough to run the DC-DC Lipo charger ?

I will look online for LiFePofe4 , you might already know the better place to get them ?

 

[JeffH]

Here is one that may work.
https://www.youtube.com/watch?v=omAhsQqwWSo
Jeff

 

[ScooterMan101]

During the first part of the video I thought it would not work since it had 4 settings 12/24/ etc voltage settings , but thanks to his through testing he did adjust the 24 volt setting in such a way that I think it could / might work with a 7 s pack.
Not what I was wanting since I have a new 4s pack that I was going to use to supply power to the Lipo DC-DC charger.
I was looking for a Buck MPPT for use with a 4s pack, but if a 7s pack would work I will go that route .
I now have one on order and I should get it anywhere from the first/second week to the end of December.

Also
I ordered a cheep 12 volt PMW controller to drop the voltage of the panel ( stated on the sticker on the back as 19.x volt output )
down to charge a Flooded/AGM/Gel 12 volt battery .
The only question about this is how big of a Flooded/AGM/Gel battery ( in amp hours ) would I need in order to enable the DC-DC charger to work properly ?

Here is one that may work.
https://www.youtube.com/watch?v=omAhsQqwWSo
Jeff