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Chinese MPPT charge controllers

Prior to the introduction of Chinese controllers, MPPT was an expensive feature found only on controllers costing hundreds of dollars. Chinese controllers cost about half the price of premium controllers.

PWM controllers have their own page.


Current production models are below; older models have been moved.


Many of the Tracer series follow a model number pattern consisting of rated current, max voltage input, and “ground”.

Example: EpEver 2206AN =

  • 2206AN - rated capacity (20A)1)
  • 2206AN - nominal charging voltage
    • 2 - 12/24v
    • 4 - 12/24/36/48v
  • 2206AN - max input voltage- 06 = 60V input2)
  • 2206AN - model series (with N meaning negative “ground”, see above)


MPPT algorithm performance

The algo is slow but performs very well under good solar conditions. Under poor or rapidly-changing solar conditions it may underperform.


Some voltage setpoints are constrained in relationship to each other. Because of this it may be easiest to write them down in this order3) (lowest to highest voltage) to make sure the logic below is followed. Then program them into the controller.

  1. “Low Voltage Reconnect Voltage” (load)4)
  2. “Boost Reconnect”5)
  3. Then “Float Charge”
  4. Then “Boost Charge”
  5. Then “Equalize Charge”
  6. Then “Over Voltage Reconnect” (load)6)
  7. Then “Charging Limit”7)
  8. Then “Over Voltage Disconnect” (load)

PARA errors mean the internal logic of the setpoints has been violated:

The following rules must be observed when modifying the parameter's value in user battery type
Over Voltage Disconnect Voltage (load) > Charging Limit Voltage ≥ Equalize Charging Voltage ≥ Boost Charging Voltage ≥ Float Charging Voltage > Boost Reconnect Charging Voltage.
Over Voltage Disconnect Voltage (load) > Over Voltage Reconnect Voltage (load)
Low Voltage Reconnect Voltage (load) > Low Voltage Disconnect Voltage (load) ≥ Discharging Limit Voltage.
Under Voltage Warning Reconnect Voltage (load)8) > Under Voltage Warning Voltage (load) ≥ Discharging Limit Voltage (load)9)
Boost Reconnect Charging voltage > Low Voltage Reconnect Voltage.

img.mousetrap.net_boondocking_mt-50_displayevil.jpg Tracer (and the Renogy rebrands) refer to the Absorption stage as “boost”. This is an unforced error; the nonstandard term confuses newcomers and conflicts with the already-existing “MPPT boost” term.

The LOAD icon (light bulb ON/OFF) indicates whether the LOAD terminals are powered, not whether or not anything is connected to them or consuming power.

battery SOC icon

The battery icon found on many Tracer controllers is unnecessary and misleading. The manual claims it is a State of Charge meter but there is no guide to reading it. Since the same voltage can result in different display during charging and non-charging scenarios, it may actually be useful to think of as a charging indicator rather than state of charge indicator. Secessus' unscientific observation reveals these weak correlations:

Charging Not charging
5 bars / 100% Float
4 bars / 80% late Absorption
3 bars / 60% early Absorption ⇐ Vfloat
2 bars / 40% late Bulk, >=Vfloat
1 bar / 20%: early bulk early Bulk, <Vfloat ⇐ Vreconnect
0 bar / 0%: not charging ⇐ Vlvd

lithium compatibility

EpEver says the Tracer series is not fully lithium compatible since they cannot “activate” Li batteries that have shut themselves down.10) [IMO this is an unnecessarily high criterion which other mfg do not adhere to. Almost any configurable charger can be used for lithium. - secessus]

There is anecdotal evidence that the PC software can configure the controller to stop charging below a given temperature.


A series

images-na.ssl-images-amazon.com_images_i_51ea6qpt0zl._ac_ul160_sr160_160_.jpg The A series has a front LCD display and rear-facing heat fins. It can handle up to 100v of solar input. The A series (and BN below) use the MT-50 display. Communications are via RJ-485 adapter and the LS-B protocol (pdf). Open source software is available.

AN series up to 40A

The AN variant is “negative ground” but is otherwise indistinguishable from the A series.

AN series 50A and higher

The >=50A AN series uses the same display and possibly firmware of the smaller AN units, but has several differences:

  • very large and heavy; make sure you have space before ordering one
  • 100v, 150v, and 200v versions is instead of 60v/100v in smaller AN
  • removable cover over wiring terminals – see pic at right; terminal screws are not visible
  • battery voltage sensing wire can be plugged into a small terminal plug
  • LOAD output is removed; low LOAD functionality remains via small terminal plug1,used only for relays and controlling generators


  • 5415AN - 50A, 12/24/48v banks, 150v input
  • 5420AN - 50A, 12/24/48v banks, 200v input
  • 6210AN - 60A, 12v/24v banks, 100v input
  • 6415AN - 60A, 12/24/48v banks, 150v input
  • 6420AN - 60A, 12v/24v/48v banks, 200v input
  • 8415AN - 80A, 12/24/48v banks, 150v input
  • 8420AN - 80A, 12/24/48v banks, 200v input
  • 10415AN - 100A, 12/24/48v banks, 150v input
  • 10420AN - 100A, 12/24/48v banks, 200v input

When assessing input voltage needs, see the manuals that specify how ambient temperature affects Vmax tolerance.

BN series

images-na.ssl-images-amazon.com_images_i_51qoyhrxkrl._ac_us160_.jpg The BN series has no display. It has massive front-mounted heat fins. It is the first Tracer with so-called negative ground. The BN controllers use the same comms setup as the A series above. Some users have reported sluggish PPT under changing conditions.

eTracer BND series

This 150v, “negative ground” controller looks like a BN with an inset display module. Comms are by RS232, CAN BUS and Ethernet. The eTracer is also sold as the Renogy Commander. manual (pdf)

Triron N series


The Triron is a modular controller:

…which can be integrated with different display and interface modules to meet a variety of functional requirements…. There are three display modules (Basic 1(DB1), Standard1(DS1) and Stardard2(DS2)) and four interface modules (USB COM Slave(UCS),Relay COM Slave(RCS), Relay COM Master(RCM) and Dual USB1(USB1)). Users can choose any combination of these modules according to their needs. – datasheet
  • negative ground
  • modular construction
  • low temperature charging cutoff11)

The Triron is also sold as the Renogy Rover, which can be programmed using the free software.


SPP programmers

i.ebayimg.com_00_s_oduwwdg1ma_z_3eiaaosw9ezzi_dl_58.jpg The SPP-01 and -02 appear to be devices that can be used to backup or configure Tracers in the field. They are largely undocumented.

MT-50 display

us.v-cdn.net_6024911_uploads_editor_l6_v53xktbye01p.jpg The MT-50 display is not a meter per se. It is a display for controller information and an interface by which configuration changes can be made. The default screen shows input from panel (volts and amps), output to battery (volts and amps), and output to LOAD (volts and amps). The LOAD icon (light bulb) has rays around it when the load circuit is on; this does not mean there is a load present.

Because of a tweak Renogy made to their version of the controllers, the plain MT-50 will not work and you must pay extra for the Renogy MT-50.

Note: some comms problems can be solved by adjusting the baud rate.

MT-75 display

A MT-75 display is available in some regions. It has two RJ-45 inputs for connection to both the charge controller and an inverter

wireless modules

img.mousetrap.net_boondocking_screenshot_20191004-112248.jpgEpever makes bluetooth and wifi modules that plug in to the same port the MT-50 uses. This allows the free smartphone app to connect to the controller over bt/wifi for configuration and display. Pic to the right is from secessus' rig. Renogy rebadges the modules for their [rebadged] controllers.

Note that these apps talk directly to the modules over BT/Wifi; they do not pair to the phone or connect to the wifi access point. Connect to the module through the app itself.

See this post for advanced use of the wifi version.


images-na.ssl-images-amazon.com_images_i_51nrvp7ovwl._ac_us218_.jpg The Eco-worth was one of the first low-priced true MPPT controllers on the market. Eco-worthy refers to three stage charging as “impulse, bulk, and float”. Youtube review: eBay MPPT Solar Charge Controller Review - 12v Solar Shed.

MPPT boosting controllers

images-na.ssl-images-amazon.com_images_i_51n1algrmwl._ac_us160_.jpgThe mpt-7210a 10A controllers are indeed MPPT, but of limited use for RVers. They are strictly “boosting” (upconverting) controllers instead of the usual downconverting controllers. This means they could be used to charge a 24v bank from 12v panels. Or, for example, a 48v ebike from 12v portable panels. [This company needs to make a normal MPPT at this price point! – secessus]

fake MPPT units

The following units are “fake” in the sense that they do not do MPPT. Some are PWM, some are shunt. This doesn't mean they won't work but it does mean they are marketed incorrectly. Adjust your willingness to pay based on actual function.



images-na.ssl-images-amazon.com_images_i_51t1rrf7rjl._ac_us218_.jpgThe CPT is a non-adjustable 10A controller with claimed 100v input. Adam Welch tested to 40+ voltage. Vabs appeared to be 14.7v and Vfloat appeared to be 13.5v, although it could be a charge-and-stop unit that happened to rest at 13.5v. CPT manual Youtube review: Another Cheap MPPT Charge Controller - CPT-LA10 - 12v Solar Shed


images-na.ssl-images-amazon.com_images_i_51tvjtt53sl._ac_us160_.jpg Note: while early versions (1.6) were reported to do actual MPPT, later versions (2.3) are reported to be dumbed down. The later versions still do DC-DC conversion but do not track powerpoints; they run the panels about 2v higher than battery voltage. See the comments on this test video and these blog posts. Youtube review: UEIUA Cheap MPPT Solar Charge Controller - 12v Solar Shed


i.ebayimg.com_thumbs_images_m_mpzetvhxbeg1692y3lhzu0g_s-l225.jpgThe CPS appears to be the new/dumb CPY in a different case with a much bigger heatsink.

M10 / T10

i.ebayimg.com_thumbs_images_m_m-rs8akwzdfagsa6u4vuzja_s-l225.jpgThe M and T series are adjustable shunt controllers.


i.ebayimg.com_thumbs_images_m_mxy3693tlp_jph7ac-swmvq_s-l225.jpgCMT controllers are non-adjustable PWM of decent quality, sometimes sold by unscrupulous or uninformed sellers as MPPT.


i.ebayimg.com_thumbs_images_m_msn0fmxrtlt1eegurjfs-eg_s-l225.jpgThe waterproof controllers are pwm at best. Confirmed by Adam Welch.

two-digit “10” means 100A
10 == 100v, 15 == 150v, 20 == 200v
reconnect loads after regaining this voltage
if voltage falls below this in Float then Boost/Absorption will be restarted
reconnect at this voltage aftr OVD has kicked in
highest voltage the controller will allow for charging
low voltage warning turns off here
no effect other than warning in standalone systems
electrical/solar/tracer.txt · Last modified: 2023/01/18 13:33 by frater_secessus