diy solar

diy solar

Power supply and an mppt VS a dedicated ac lithium battery charger?

Terrapin

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Joined
Jan 4, 2021
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315
Location
New England, USA
Flat out question since it seems to me I will be needing to buy a variable power source to balance my cells B4 my build. (thanks to all for the responses on the US high quality sources to avoid this, but I can't afford what I'd hoped in buying pre-matched cells here in the us).

Instead, 280ah Eve/Lishen cells were just ordered from Will's Aliexpress link. Overkills 120A 4S BMS is on hand already as well.

So I have a unit like this coming for the prebuild top balancing: https://www.ebay.com/itm/Dc-Power-S...575549?hash=item1cfff8bc7d:g:L~wAAOSw8UNgFvrN

This leaves me to question if I can charge the battery after it is built using this supply directly relying on the BMS for the correct charge profile and shut off?

Or, Since I do hope to upgrade from the crap PWM that came with my suitcase 120w panels to even more portable panels later, can a properly sized MPPT be used to mutli-stage charge the battery using the power supply when AC is available rather than buying a dedicated LFP charger at around the 30a this power supply can offer?

Does this even work?
 
Flat out question since it seems to me I will be needing to buy a variable power source to balance my cells B4 my build. (thanks to all for the responses on the US high quality sources to avoid this, but I can't afford what I'd hoped in buying pre-matched cells here in the us).

Instead, 280ah Eve/Lishen cells were just ordered from Will's Aliexpress link. Overkills 120A 4S BMS is on hand already as well.

So I have a unit like this coming for the prebuild top balancing: https://www.ebay.com/itm/Dc-Power-S...575549?hash=item1cfff8bc7d:g:L~wAAOSw8UNgFvrN

This leaves me to question if I can charge the battery after it is built using this supply directly relying on the BMS for the correct charge profile and shut off?

Depends. The PS is dumb. The BMS knows nothing of the proper charge profile. Relying on the BMS cut-off to regularly cut your battery off is not a good idea. However, if you leave the PS at 13.6V, it will eventually get the battery charged without any potential for damage.


Or, Since I do hope to upgrade from the crap PWM that came with my suitcase 120w panels to even more portable panels later, can a properly sized MPPT be used to mutli-stage charge the battery using the power supply when AC is available rather than buying a dedicated LFP charger at around the 30a this power supply can offer?

Does this even work?

If you're asking, "Can I feed a MPPT SCC with a 30V/10A Power supply instead of a solar panel?"

The answer is yes. It's a better solution than charging at 13.6V because you'd only get 13.6V * 10A = 136W. If you're feeding 30V/10A into the MPPT, it will use the whole 300W and charge the battery at a higher current.
 
Depends. The PS is dumb. The BMS knows nothing of the proper charge profile. Relying on the BMS cut-off to regularly cut your battery off is not a good idea. However, if you leave the PS at 13.6V, it will eventually get the battery charged without any potential for damage.




If you're asking, "Can I feed a MPPT SCC with a 30V/10A Power supply instead of a solar panel?"

The answer is yes. It's a better solution than charging at 13.6V because you'd only get 13.6V * 10A = 136W. If you're feeding 30V/10A into the MPPT, it will use the whole 300W and charge the battery at a higher current.
Thank you so much again. I never even thought of it as an advantage.

I really appreciate you helping me dial this stuff in as I go. I am an avid freshwater fisherman and air gunner and always try to help on those forums. So I often answer the same questions over and over to different people. I feel like this place is my karma reward for trying to do that there. You've been a lot of help here. I hope it comes back around to you from somewhere as well... Knowing it will fly I am off to find the perfect MPPT on Will's videos.
 
Im building a 200 Ah 48v supply for my boat. I want to use the following to charge it. Does anyone see any issues?

Power Supply =Xantrex XFR 60-20 DC Power Supply (60v 20A adjustable)
MPPT = Victron Energy SmartSolar MPPT 100V 20 amp 12/24/48-Volt Solar Charge Controller (Bluetooth)
 
Yup! I already see a problem!

You just jumped in someone else thread asking for your own design information and detracting from his issue.

Where's YOUR thread at?
 
I AM THAT GUY . . . similar isn't good enough. And as far as topic in this forum, no it isn't really all that similar after all. Plus there's nothing wrong at all about multiple threads, ones that aren't really all that similar after all, is there?

Don't be a lazy hijacker. This isn't Idiocracy.
 
You do you dude :)

I have no skin in this game, Moderator please let me know forum etiquette.
 
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