Solar Panel Output Boost? ~30 V --> 51 V

[flammafeuer]

I don't have enough panels to get the total solar panel output voltage great than the voltage my MPPT needs to charge at 48 V levels in my test setup. I thought I had ready once about something you could put in between your solar panel and the charge controller to boost the voltage, but can't find it again if I did. Is there a device like this that would work? My final setup will have more than enough Volts, and I really need to get another panel so that I can get my voltage up, but didn't think about it soon enough.

 

[SamDeleted]

Need to Reduce solar voltage!!

Hello everyone. Need to reduce solar voltage on my temporary system. Running 2 sets of (3) 535 watt panels. Controller voltage is 145 max. I hitting that mark. On warmer days I get around 139-140v. This week was colder so I hit the 145-150v mark. I need to drop voltage by 5-10v before going into...

diysolarforum.com

This thread might help (it's a bit of a read ! )

 

[flammafeuer]

Need to Reduce solar voltage!!

Hello everyone. Need to reduce solar voltage on my temporary system. Running 2 sets of (3) 535 watt panels. Controller voltage is 145 max. I hitting that mark. On warmer days I get around 139-140v. This week was colder so I hit the 145-150v mark. I need to drop voltage by 5-10v before going into...

diysolarforum.com

This thread might help (it's a bit of a read ! )

Thanks. I went through it, but couldn't see something that would help me (maybe I missed it). Not trying to reduce the panel voltage, but boost it.

 

[Vigo]

Well, whats the details on the panels you have? There are multiple 'voltage boosting mppt' controllers available to boost a lower-voltage panel string to charge a higher voltage battery, but the issue is that you are trying to get into the thousands of watts of charging you would need several such devices as i haven't seen any larger than 600w.

Examples

You could use a simple dc-dc boost converter between your panels and your mppt but given the fairly low cost of the fully integrated 'boost mppts' i linked to above, i don't see it as being a worthwhile investment of time or dollars unless you happen to already have such a boost converter and the dollar factor becomes 0 (or amortized, maybe) and you don't mind the time spent dinking with it. Using a $45 pre-built boost converter to get 600w out seems cheap enough that i wouldn't bother with the DIY approach in most cases.

 

[lotsofsparks]

Do all mppts' have dc-dc boost capabilities? I have 11.8 v under S4 280Ah Lifeo4 battery load @ 4 - 0.2A coming from my 160W panel. I'm only getting that current I suspect because of that steep curve when you approach under voltage. I don't expect anything near a full charge without a boost of some sort. I only have a lead acid battery charger which is unsuitable. We are getting massive storms here in Australia so I feel i might have to use my booster converter in a pinch. Many of my friends have been without power for over a month now and I could be next.

 

[Kcdaniels]

On my golf cart 48v lithium pack and a 40v solar panel im using this boost controller ...taking 40v and boosting to 58.4 .. It works great !

 

[Vigo]

To answer a question, NO not all mppts have boost converter functionality.

 

[lotsofsparks]

On my golf cart 48v lithium pack and a 40v solar panel im using this boost controller ...taking 40v and boosting to 58.4 .. It works great !

That's what I need too because I also made a S14 MNC battery that charges at 58 ish volts though I need to made an additional Current detection circuit to shut it down. which makes it difficult due to solar charger current varies alot. Are you using the same chemistry.