I have an EB55 and want to max out the input watts with two panels in parallel. I have a 200 watt and a 120 watt panel wired in parallel. With a voltmeter I am getting 20.3v and 15.6 amps with no load. I know that the Bluetti will lower the amps to 8 and that with a load the volts will go lower than the 20.3. If I use an adjustable DC to DC step up booster I can adjust the output to 28v and 8 amps.

I take it you measured the amps by short circuiting the panel with your multimeter. Most multimeters with the amp measurement feature max at 10A.

As for your question, I don’t have any direct experience but this might not be worth it. You will need to factor in step-up losses and the cost of the converter.

I am new at this but in parallel the amps are added together. The multimeter measured the amps as 5.7 off the 120 watt panel and 9.2 off the 200 watt panel. It measured 20.3v. If you adjust the boost converter to 28 volts and the amps remain at 8 because of the EB 55 doesn’t that mean there will be 8 more V at 8 amps for 64 additional watts going into the input port? The converter is supposed to be around 95% efficient so this could improve the input watts significantly. The cost for cables and the converter is around $45. Sounds cheap if it works.

My concern with this idea is that the input voltage from the panels to the step up converter would not be steady and would increase and decrease with load. With clouds or any shading, the voltage would increase which would increase your step up converter output (probably) and go over your bluetti voltage maximum

Ok, that makes sense now that you explained that you measured the short circuit amps for each panel an added them.

Based on your panel measurements you should be getting around 160W with your current set up. Is that what you’re seeing?

Like @Scott-Benson said, I’d just be careful with getting too close to the 28V voltage limit for your EB55 using a DC step up booster and maybe configure it to output 26-27V if you can. You probably should go with a good quality converter as well.

Hopefully someone who has or is using a DC step up converter can share their experiences.

Hi @Bobk1000@Komitadjie ,
Thank you for posting in the forum!
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Thank you so much

I am getting around 119 input watts from both panels. It is my understanding that the volts will drop around 5 volts under load. So 15 volts times 8 amps equals 120 watts

From the documentation on the booster it doesn’t matter what’s going in, the output is supposed to remain the same. That is as long as you have enough volts and amps going in that you set the output for. So if the input watts goes lower than the output watts it will only go lower and not higher. So for as my example I have 20.3v and 15 amp for 304 watts going in. If I set it for 28v and 8 amps I only need 224 watts going in. The EB55 will only draw 8 amps so a lot of watts are wasted without the booster.