Finding an effecient ac to dc charger

Scph9002

Solar Enthusiast
Winter is coming and I got a 30KwH 48v lifepo4 bank and I just realized it would work great as a... battery lol to store cheap grid energy during the night when prices are much lower and then use that energy during the day when grid energy cost alot more.

That all is moot tho if the ac to dc charger is too ineffecient. I have measured the effeciency of some older car battery chargers and they have terrible effeciency. 75% or less.

So yeah.. any recommendations for any chargers available on alibaba that have conversion efficiency of 90% or more?

Im looking at deligreens chargers. Got in touch with their support and they said effeciency was 85 to 90%.


 
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me3

New Member
Much as I hate to say it, Multiplus or Phoenix
My AIMS is much less efficient - Heat & Noise
 

RCinFLA

Photon Sorcerer
A low frequency (large heavy transformer) hybrid inverter are normally the best efficiency chargers. They are typically in low 90's% and have good power factor during battery charging.

Many high frequency hybrid inverters do not have the best AC input charging function, using MOSFET body diodes for charger rectifiers and have a poor input AC power factor for charging batteries.

When fed from a generator, power factor of charger is as important as efficiency.
 

Scph9002

Solar Enthusiast
A low frequency (large heavy transformer) hybrid inverter are normally the best efficiency chargers. They are typically in low 90's% and have good power factor during battery charging.

Many high frequency hybrid inverters do not have the best AC input charging function, using MOSFET body diodes for charger rectifiers and have a poor input AC power factor for charging batteries.

When fed from a generator, power factor of charger is as important as efficiency.
What is your take on this charger?
This looks like the very same as will prows recommends on his site except its without retailers rebranding? :p

The tech sheet looks promising. <93% efficiency and good power factor.

Price for a 3.3 kw 48v 45 amp lifepo4 charger seem to be around 400 usd with shipping. A lot cheaper than buying these locally.

 

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MattiFin

Solar Enthusiast
48v telecom hardware could have some good options.

or something like meanwell UHP-2500 with 96% efficiency. This is not really battery charger so you might need some workarounds.
 

MattiFin

Solar Enthusiast
A low frequency (large heavy transformer) hybrid inverter are normally the best efficiency chargers. They are typically in low 90's% and have good power factor during battery charging.

Many high frequency hybrid inverters do not have the best AC input charging function, using MOSFET body diodes for charger rectifiers and have a poor input AC power factor for charging batteries.

When fed from a generator, power factor of charger is as important as efficiency.
Any examples of high efficiency LF chargers?
Victron for example doesn’t give any specs for the charger efficiency.
 

DJSmiley

Solar Addict
48v telecom hardware could have some good options.

or something like meanwell UHP-2500 with 96% efficiency. This is not really battery charger so you might need some workarounds.

Agreed.

Meanwell does make some high quality stuff, but at a price.

However, I'm quite sure the quality is much better than a generic Chinese charger. Some are fine, others are a fire-to-happen. Unless you have the knowledge to do some proper QA testing yourself I won't let an unknown chinese charger run unattended.

The DBU-3200 is for example a massive powersupply... https://www.meanwell.com/webapp/product/search.aspx?prod=DBU-3200
Capable of charging 55A...

If you want to go the cheap route, a decent powersupply will do. You only have to add something to stop it from charging when the batteries are full, but that can be done with eg a Victron BMV, using its relay to shutdown charging once the SOC eg reaches >95% or so.

A decent powersupply can be found a lot cheaper. You only need to find one with current limiting, otherwise it will shutdown.

I have for example some APC powersupplies from an old router. Each one provides 50A current, 2800W each. And 3 of those can be connected in parallel. However, it requires 3 240V circuits to run them all :)

( https://download.schneider-electric...6Z8LDN_R0_EN.pdf&p_Doc_Ref=SPD_ASTE-6Z8LDN_EN )

I see them for sale on Ebay for $250 each

The majority of those have a remote switch option, so if you have some basic electronics knowledge it's pretty easy to enable/disable them using a BMS / BMV or whatever

You could even build something with a CAN/RS385 to your BMS, and an ESP to make something with WIFI, NTP time sync and based on the tarifs of your power company


As for that massive APC powerbrick I have: I have 3 of them, and if anyone interested, I don't need 3.. However, they are located at my house.. And that's in the Netherlands. The majory of the folks here are from the US, and shipping is a PITA.... so for anyone interested in Europe, feel free to drop me a msg, but outside Europe it's not worth the hassle to ship..
 
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