Charge 52V Dolphin with this MPT-7210A?

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Stu Summer   1 W

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Charge 52V Dolphin with this MPT-7210A?

Post by Stu Summer » Jun 15 2017 7:57pm

MPPT.jpg
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Can I charge my Luna 52V Dolphin pack with a 285W solar panel by using this MPPT Solar Charge Controller set at, say, 56V or 52V? Will it damage the battery?

Thanks, I'm pretty wet behind the ears.

Stu Summer
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Sunder   100 MW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by Sunder » Jun 15 2017 8:54pm

Should be fine. Just make sure you use the current limiting function, if your battery can't handle the 5-6amps that the solar panel can put out.

I have one of those to charge a a 24v battery. Difference is though, my battery is 130Ah, so could soak up anything my solar panels could throw at it.
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After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

kdog   10 kW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by kdog » Jun 16 2017 6:41am

the main thing is that you need to know the exact voltage to charge to.
given by #cells x 4.2v for li-ion and #cells x 3.6v for lifepo4
what is the configuration of the luna battery?
im guessing its a 14 cell li-ion so its max charge is 58.8v
this is an absolute max. if you accidently charge above that to say 63v you will have destroyed your battery and may have a potential fire on your hands at some stage (maybe down the track)
you can undercharge but the BMS wont balance until nearly full.
can you set V accurately on your MPPT charger? 56 or 52 is nowhere near accurate enough
k

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Sunder   100 MW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by Sunder » Jun 16 2017 10:58am

kdog wrote:the main thing is that you need to know the exact voltage to charge to.
given by #cells x 4.2v for li-ion and #cells x 3.6v for lifepo4
what is the configuration of the luna battery?
im guessing its a 14 cell li-ion so its max charge is 58.8v
this is an absolute max. if you accidently charge above that to say 63v you will have destroyed your battery and may have a potential fire on your hands at some stage (maybe down the track)
you can undercharge but the BMS wont balance until nearly full.
can you set V accurately on your MPPT charger? 56 or 52 is nowhere near accurate enough
k
Those controllers can be set to 100th of a volt. How accurate they really are are another matter entirely.
eBike: Q100H on 16S with Phaserunner FOC Controller
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eHouse: Still on grid, but with LTO batteries and 3kw LF inverter...

After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

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tomjasz   1.21 GW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by tomjasz » Jun 22 2017 10:42pm

Do you already own the charger? I have a new unused for a discounted price...
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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tomjasz   1.21 GW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by tomjasz » Jun 22 2017 10:43pm

Do you already own the charger? I have a new unused for a discounted price...

BTW there a couple of good videos, one from a Brit that works out the kinda crazy setting details.
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

forsa355   1 µW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by forsa355 » Oct 18 2017 7:34pm

if this charger is so cheap ($44 on Amazon), how come more people don't use this as a cheap alternative to a Cycle Satiator? Seems to do similar thing (albeit without the bells and whistles). Hook up a cheap 12v wall wart you may have kicking around to power it, and you have full control over max charge voltage and charging amperage.

Is anyone using it for this purpose? I'd love to get one to charge a 52v shark pack to 80%, 90% etc. at home.

Amazon link: https://www.amazon.com/Docooler%C2%AE-B ... =MPT-7210a

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Sunder   100 MW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by Sunder » Oct 18 2017 9:34pm

The specs on these chargers are exaggerated.

I had a 14.8v, 150A capable power supply on one side, and a very low resistance 24v battery on the other side. It couldn't even push 2A.

Also, some sellers say that it's MPPT. Thats crap. If the input side voltage goes above the output voltage, it just passes the voltage through, which can overcharge the battery.
eBike: Q100H on 16S with Phaserunner FOC Controller
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After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

heathyoung   1 MW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by heathyoung » Oct 24 2017 9:18pm

Its a boost converter MPPT - if input > output, then this will happen normally.

There has been quite a bit of testing with these, and people are reporting decent power, 4-500W.
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Sunder   100 MW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by Sunder » Oct 25 2017 5:06pm

Hmm. Mine was advertised as a "MPPT Buck and Boost Controller"

I read that as (MPPT Buck) + Boost, as I didn't think MPPT boost existed. I still expected it to control charge voltage both directions though.

Still doesnt explain why I can only get 2A boost out of it. I wonder if the originals were such good value for money that there are cheap knock offs already.
eBike: Q100H on 16S with Phaserunner FOC Controller
eMotorscooter: Vectrix VX-1 on 36S
eCar: Mitsubishi Outlander PHEV... Waiting for warranty to expire
eHouse: Still on grid, but with LTO batteries and 3kw LF inverter...

After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

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Sunder   100 MW

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Re: Charge 52V Dolphin with this MPT-7210A?

Post by Sunder » Nov 07 2017 9:15pm

Alright, I am an idiot.

After what Heath said, I retested my system. The issue is a 15m cable using 1mm^2. That is rated to 11A depending on the conductor, but at 10A, the voltage drop over the whole length is 2.55v, The battery is only "seeing" a lower voltage, hence lower potential difference between battery and charger, and lower charge rate.

I've unfairly maligned this charger. My apologies.
eBike: Q100H on 16S with Phaserunner FOC Controller
eMotorscooter: Vectrix VX-1 on 36S
eCar: Mitsubishi Outlander PHEV... Waiting for warranty to expire
eHouse: Still on grid, but with LTO batteries and 3kw LF inverter...

After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

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