Mex has a thread about equalizing with this sort of gizmohttp://www.amazon.com/DROK-Constant-Current-Converter-Regulated/dp/B00E8D7XYGThere are many of these on ebay with different specs, so that one might not be the right one, but for this idea assume there is a right one.The idea would be to use one of these with a standard $15 PWM solar controller to buck its amps while keeping voltage to the battery under 15v. Would it go before or after the controller? What settings would be used for adjustable voltage and current? Would you have to keep twiddling with the settings all day? Not too clear about how you get the amps to taper either. You guys are supposed to solve all that! :)Background-- we know that an MPPT controller has a buck converter plus an MPPT feature. "MPPTs" go to PWM to do the Absorption Stage and Float Stage, but they will keep on bucking the amps after going PWM.So I am thinking you could use one of these little buck converter gizmos somehow to work with your basic PWM controller and get more amps to the limit of the controller's amps rating-- higher amps than the "12v" panel's Isc which is now the max amps.

I don't "think" this will start a fight between the gizmo and the controller. The gizmo would go between the controller and batteries.I much prefer the 600 watt version of this type of DC to DC booster. It is much more robust.A booster INCREASES voltage. If you wanted to FLOAT control a PWM controller, use a BUCK gizmo, but be aware of the Delta T limitation. I would choose a silicon rectifier and drop voltage .7 volts or a shottky and drop voltage .4 volts.

Ok there are zillions of step up step down buck converters, some mention they are for solar. They seem to be low amp but intended to stabilize the varying solar voltage input for a steady voltage output.Not sure. I have no clue.I thought the buck converter would go between the panel and the controller. Input is panel voltage and current depending on sunshine during the day but panel output max is say 22v and 8 amps to a 20a controller that passes through whatever amps it gets while not letting the battery get over its voltage set point, say 14.8vThe gizmo should buck that 8 amps higher using the "extra voltage" the panel is at above battery voltage.I just want to buck the amps the panel passes through the controller to the limit of the controller's amps rating and keep the voltage seen at the battery from going over 14.8v

All I know is I would appreciate it if each of you would check in the next time we see a mushroom cloud off in the distance. I want to know who got taken out while frying their batteries. lol

Or get a good controller. Plenty of voltage in the panels.

Buck. Reduces voltageBoost increases voltageExample an 8 amp power supply at 22vMPPT takes the extra voltage and creates ampsIt tracks the battery acceptance rate and does it's best to keep voltage where the batteries accept the most watts up until it gets to the set point...say 14.8vTo me using a boost between controller and batteries it's futility except for equalizing pIt would allow for one voltage and no floatIf you had power from the controller at 13.2v. It would be boosted to 15v or what ever you have set it atIt might not work at allMany controllers need to sense battery voltageAsk Landyatch .... If he disconnects the input power can he read voltage on the input side, from a battery connected to the output

Buck Your Solar with a Mex Gizmo? | Good Sam Community

106 Replies

BFL13
Explorer II
Oct 12, 2014
I want to still have the controller controlling but just feed it more amps than the panel would normally feed it. Seems to me the gizmo would then go between panel and controller.

Do these type of gizmos accept the panel output of V and A as input and you can adjust up the amps to the controller without screwing up the voltages the controller would accept (limit is the Voc rating limit I suppose)

If I want to just have a two stage controller that gets the batteries up to Vabs and then holds that voltage till dark (no Float), then do I even need the controller? Why not just use the gizmo between panel and battery? Advantage over a controller is the higher amps, and still get the output voltage limit setting?

I want to create the situation like where the MPPT controller has gone into PWM but its bucking is still on. I am not trying to make an MPPT. For charging during Bulk the idea would be more amps than with PWM pass-through, just no MPPT.
MrWizard
Moderator
Oct 12, 2014
Buck. Reduces voltage

Boost increases voltage

Example an 8 amp power supply at 22v

MPPT takes the extra voltage and creates amps
It tracks the battery acceptance rate and does it's best to keep voltage where the batteries accept the most watts up until it gets to the set point...say 14.8v

To me using a boost between controller and batteries it's futility except for equalizing p

It would allow for one voltage and no float
If you had power from the controller at 13.2v. It would be boosted to 15v or what ever you have set it at

It might not work at all
Many controllers need to sense battery voltage

Ask Landyatch .... If he disconnects the input power can he read voltage on the input side, from a battery connected to the output
time2roll
Nomad
Oct 12, 2014
Or get a good controller. Plenty of voltage in the panels.
JiminDenver
Explorer II
Oct 12, 2014
All I know is I would appreciate it if each of you would check in the next time we see a mushroom cloud off in the distance. I want to know who got taken out while frying their batteries. lol
BFL13
Explorer II
Oct 12, 2014
Ok there are zillions of step up step down buck converters, some mention they are for solar. They seem to be low amp but intended to stabilize the varying solar voltage input for a steady voltage output.
Not sure. I have no clue.

I thought the buck converter would go between the panel and the controller. Input is panel voltage and current depending on sunshine during the day but panel output max is say 22v and 8 amps to a 20a controller that passes through whatever amps it gets while not letting the battery get over its voltage set point, say 14.8v

The gizmo should buck that 8 amps higher using the "extra voltage" the panel is at above battery voltage.

I just want to buck the amps the panel passes through the controller to the limit of the controller's amps rating and keep the voltage seen at the battery from going over 14.8v
MEXICOWANDERER
Explorer
Oct 12, 2014
I don't "think" this will start a fight between the gizmo and the controller. The gizmo would go between the controller and batteries.

I much prefer the 600 watt version of this type of DC to DC booster. It is much more robust.

A booster INCREASES voltage. If you wanted to FLOAT control a PWM controller, use a BUCK gizmo, but be aware of the Delta T limitation. I would choose a silicon rectifier and drop voltage .7 volts or a shottky and drop voltage .4 volts.

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Buck Your Solar with a Mex Gizmo?

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