Need a reasonably priced method of equalizing charging.

[somawheels]

Ok, so if I could use this? http://www.ebay.co.uk/itm/110V-220V-...QAAOSwpDdVPP~t

To equalize my 24v batbank by using it on a 31.2v (aprox) setting (2.6v*12 cells).

I need a 10A one but this is just an example.

[Mike90250]

sadly my charge controller doesn't have an equalizing function.
Why is solar better for EQ stage? , Will it take the same amount of time as if the generator was on?

It depends on how low the batteries are, and if your solar can provide enough charge. Apparently, you are low on solar PV and need to run the generator every 3 days or so to keep the batteries healthy.

[somawheels]

Apparently, you are low on solar PV and need to run the generator every 3 days or so to keep the batteries healthy.

I don't understand? I will have 1.53KW of panels on a 420AH 24v bank.

[Mike90250]

if your solar cannot keep the batteries charged your loads are too high, 1.5Kw of panels @ 28V should yield 50A, which getting close to the upper limit for the batteries to safely absorb without heating up. So if you can't get enough charge done in a day, to EQ, then you need to conserve power, shift loads to a generator, or charge the batteries from a generator.
Generally, over 300 or 400w, MPPT controllers are a better way to harvest the power. With PWM, you need to have PV array wired to provide at least 35V, if you are only wired for 28V, you will destroy your battery bank. With MPPT controller, your array should be wired for 45 - 65V for best efficiency.

[jflorey2]

Right, so If i get this 32V 5a power supply to my battery bank (while no loads are on it), I will be able to perform an EQ charge. 5A is to low for me. like this

Something like that would work - again, provided you can drop all other loads for the EQ.

[somawheels]

Ok, thanks jflorey2

Generally, over 300 or 400w, MPPT controllers are a better way to harvest the power. With PWM, you need to have PV array wired to provide at least 35V, if you are only wired for 28V, you will destroy your battery bank. With MPPT controller, your array should be wired for 45 - 65V for best efficiency.

The panels I was considering are 30.2(vmp) and VOC of 37.98, so should be okay?

[sensij]

Ok, thanks jflorey2


The panels I was considering are 30.2(vmp) and VOC of 37.98, so should be okay?

No. The 30.2 is at STC (25 deg C). Actual operating temperature will be higher than that, and voltage will be lower. Those panels in parallel in a PWM controller won't support EQ.

It takes very little current for the voltage to fall from Voc to Vmp. It is possible the panels could help hold the EQ voltage during the day if you want to give the generator a break, but I don't think they will get the battery up to the voltage on their own.

[somawheels]

My questions often lead to the same answer: Use an MPPT charge controller.

[sensij]

If you want to stay with PWM, consider using a 72 cell solar panel.

[inetdog]

I don't understand? I will have 1.53KW of panels on a 420AH 24v bank.

What counts here is the total watt-hours you consume each day compared to the watt-hours the panels produce.
For example a 1.5kW system in northern US in winter may only produce 3kWh each day and not all of that can go into the batteries as they approach full charge.

A 200W load running 24 hours per day will use 4.8kkWh per day.

For details on W and Wh, read the off-grid sticky threads.

PS: You do not need (or want) an equalize charge cycle. You need a makeup charge cycle, best done the way Mike suggests.

[Mike90250]

30Voc panels will not be able to reliably EQ a 24v battery bank. you would have to put them in series and use a MPPT controller to accomplish EQ

[somawheels]

What do people think of this MPPT charge controller.

http://www.bimblesolar.com/offgrid/mppt/itracer45a-mppt

For use with 48v PV

The EQ is a bit low, but.... good price.

[somawheels]

Can anyone recommend an mppt charge controller that can use 2KW PV and can perform an equalizing charge?
This looked nice, but there's no reviews on it so i wouldn't buy it.
http://www.ebay.co.uk/itm/EPsolar-iT...MAAOSwd4tT7x~5

[Mike90250]

I use a 200v rated Midnight Classic on my small 2Kw array. I use a 150v rated Morningstar MPPT 60 on my 3Kw array (48V battery bank)