What is the difference between MPPT Solar Light Controller And Regular MPPT ?

[malborn]

I was searching on ameresco webpage. some of charge controller listed as mppt solar lighting controller, whereas some of them listed as just mppt solar controller. exempt for current difference. What is the difference between these two ? Can both of them use on lighting system ?

http://www.amerescosolar.com/tristar...c-includes-rts

http://www.amerescosolar.com/ss-mppt...5-amp-mppt-lvd

thank you.

[SunEagle]

I was searching on ameresco webpage. some of charge controller listed as mppt solar lighting controller, whereas some of them listed as just mppt solar controller. exempt for current difference. What is the difference between these two ? Can both of them use on lighting system ?

http://www.amerescosolar.com/tristar...c-includes-rts

http://www.amerescosolar.com/ss-mppt...5-amp-mppt-lvd

thank you.

As you noted, besides the amperage rating difference the TriStar can charge 4 different battery voltage systems (12,24,36,48) while the Sunsaver only 2 (12 & 24v).

My guess is that they both have multiple control programs to use on a lighting system. The TriStar probably has a higher amp rated "Load" circuit than the Sunsaver.

[Amy@altE]

You are starting backwards. What light are you trying to power, for how long, and where? Neither of those charge controllers will do the light control on their own. The 15 needs the Morningstar PC MeterBus Adapter and I don't think the 30 can do it at all. The Midnite Solar Kid may be right for you, but again, without knowing what you are trying to do, I can't be sure.

[Wy_White_Wolf]

Either can be used on a lighting system but only the one can control when the lights turn on and off. With the non-lighting controller you operate the lights manually or with a separate timer.

WWW

[KyMtMan]

I am charging a 24v 875ah forklift battery with one 255watt 30v 8.5amp panel, how long will it take using a solar controller.

[Sunking]

I am charging a 24v 875ah forklift battery with one 255watt 30v 8.5amp panel, how long will it take using a solar controller.

You already answered the question. 875 Amp Hours / 8,5 Amps = 102.9 Hours. Based on an average 4 Sun Hour about a month..Your minimum charge current should be 87.5 amps or 2000 watt panel for that battery. That would get you down to 4 or 5 day recharge.

[Amy@altE]

How much power does the light use, and therefore how much power will you be using and replacing a day?

[Wy_White_Wolf]

I am charging a 24v 875ah forklift battery with one 255watt 30v 8.5amp panel, how long will it take using a solar controller.

You may think your charging it but you're not. 30.5V is not high enough voltage to charge the battery. You need to get the VOC in the 35 to 36V range. Also a charge rate of less that C/100 (875AH/8.5A) would only maintain the battery from self discharge.

WWW

[Amy@altE]

You may think your charging it but you're not. 30.5V is not high enough voltage to charge the battery. You need to get the VOC in the 35 to 36V range. Also a charge rate of less that C/100 (875AH/8.5A) would only maintain the battery from self discharge.

WWW

Nice catch, I missed that. You are trying to charge a 24V nominal battery with a 20V nominal panel. May work a little when it's cold out, but won't work when it's hot.

[KyMtMan]

I have 8ea 255w..30v 8.5amp panels ; if I parallel them in two sets of 4 then series these two, would that work for the battery? that would give me 60v and 34amps ! correct if wrong... should be able to charge the battery.I am charging a 24v 875ah forklift battery with one 255watt 30v 8.5amp panel, how long will it take using a solar controller.

[Amy@altE]

You could wire 4 parallel strings of 2 in series using a combiner box like the Midnite Solar PV6, with a 15A breaker for each of the 4 strings. However, with 8 of those panels, 255W x 8 = 2040W / 24V battery bank = 85W coming out of the charge controller. Charge controllers are rated by output, not input. Add 25% safety (per NEC) and you need 106A of charge controllers. You would probably be better off using two 60A charge controllers, each with 2 strings of 2 panels. 106A going into a 875Ah battery would only take about 4 hours (assuming you are only using 50%).

[KyMtMan]

I have added 8ea 255watt (listed above) just installed yesterday and purchased 2ea 60 amp Aims charge controlers. I purchased a 6000 watt 24v Aims inverter; 240v output. Here are my intentions, first I want to use the 8 panels to charge the 875ah battery for backup and on occasion to use power tools when feasable. I will wire the output of the inverter to my grid tie system and store extra watt made to the grid tie. Plan to use the Aims cc to tie to the battery. Question? what would be the best way to get the most efficient use of my equipment. I could buy a smaller inverter and tie to the input of the Aims 6000. This would let the Aims inverter charge the battery with enough left to power my tools in the shed.