Independent comparisons. We may earn from shop links. More info

Solar charge controller buying guide

Updated: October 2026

You are about to buy a regulator for a 12 V leisure battery in a shed, and the amazon.co.uk shelf in this set runs from £8.48 to £139.99. A solar charge controller buying guide only helps if you settle the battery and the panel before you sort by price. The twelve listings captured on 19 October 2026 mix PWM units, units titled MPPT, and one 15 W panel kit. This page is the question order: voltage, chemistry, cold open-circuit voltage, then charge current. Prices and review counts sit on the [solar charge controller comparison](/hub/electrical-equipment/solar-charge-controller). Nothing here is a lab test. A qualifying Amazon purchase can earn us a commission at no extra cost to you.

You are about to buy a regulator for a 12 V leisure battery in a shed, and the amazon.co.uk shelf in this set runs from £8.48 to £139.99.

Our top picks

Victron Energy Victron SmartSolar MPPT 100/15

Best overall

Victron Energy Victron SmartSolar MPPT 100/15
8.6/10about £61.60
View offer
Topcloud Topcloud 10A PWM

Best value

Topcloud Topcloud 10A PWM
7.2/10about £8.96
View offer
Depvko Depvko 30A PWM

Rank 3

Depvko Depvko 30A PWM
7.3/10about £8.48
View offer
On this page
  1. 1.Match the battery voltage and the chemistry
  2. 2.Keep cold open-circuit voltage inside the controller
  3. 3.Size the charge current, then look at the load output separately
  4. 4.Read the title against the shelf

Match the battery voltage and the chemistry

Start with the battery you already own. A controller that auto-senses 12/24 V still has to land on the voltage that battery actually is. The Topcloud 10 A at £8.96 says it adapts to 12 V or 24 V and then asks you to pick a chemistry on the LCD. The AeternaSol 10 A at £18.99 says 12 V only, and it is not for 24 V or 36 V. The Depvko 30 A at £8.48 and the Rolokit 30 A at £9.99 say lead-acid only, and they tell you not to charge lithium. The Topcloud bullets name lead-acid (open, AGM, gel), ternary lithium, and LiFePO4, and they tell you to select the mode before use. The Victron SmartSolar 100/15 at £61.60 mentions battery presets in the app text, but the captured bullets do not list the chemistries. A 12 V gel battery and a 12.8 V LiFePO4 are not the same charge profile.

Keep cold open-circuit voltage inside the controller

Open-circuit voltage, often printed as Voc on the panel label, is the voltage with nothing connected. It rises when the panel is colder than the 25 °C the label assumes. Victron's BlueSolar MPPT installation manual, for the 75/10 up to 100/20 family, asks you to keep that cold Voc inside the model's ceiling. On the Victron SmartSolar MPPT 100/15, the model name says 100 V. If you put two panels in series, you add their Voc figures and then allow for a cold morning. The Y&H 60 A listing at £69.99 prints a 150 V ceiling and has 4.1 from only seven reviews. If your panels will be in series, use MPPT or PWM solar charge controller. A shed battery that never feeds the consumer unit does not, by itself, need an EREC G98 or G99 form.
Victron Energy Victron SmartSolar MPPT 100/15

Testsieger

Victron Energy Victron SmartSolar MPPT 100/15
8.6/10about £61.60
View offer

Size the charge current, then look at the load output separately

Charge current is the amps the controller is allowed to push into the battery. A rough check, arithmetic rather than a datasheet, is panel watts divided by battery volts: about 10 A near 120 W on 12 V, 15 A near 180 W, and 30 A near 360 W, before losses. Read the load or USB figure on its own. The Topcloud 30 A bullets state 30 A charge and 10 A discharge. The Rolokit states dual USB at 5 V / 3 A, which is a phone port, not a 30 A load. UK reviews include a Rolokit USB port that smoked after a few minutes. The connect order belongs on the how to connect a solar charge controller page. Several listings say battery, then panel, then load. The SmartSolar and BlueSolar captures do not print that sentence.

Read the title against the shelf

The Depvko listing at £19.54 says 100 A and MPPT in the title. In this capture it is filed under PWM controllers, it weighs 290 g, and a UK review says it is not a proper MPPT. The AeternaSol 100 A at £39.99 has a captured weight of 140 g and only 12 reviews. The POWOXI row at £54.99 is a 15 W panel with a built-in controller, 1.02 A on the attribute line. It is not a 15 A regulator. The elejoy 60 A at £139.99 is 2.0 from three reviews and does not reconcile 36 V with 12/24/48 V. Who should shortlist which honest row is the job of the best solar charge controller page.

Common questions

Do I need 12 V, 24 V, or a controller that does both?
You need the voltage of the battery you will charge. A 12/24 V auto listing, such as the Topcloud and Depvko PWM rows, still has to see a battery with enough voltage to be recognised as one or the other. The AeternaSol 10 A bullets say 12 V only.
Will this charge a LiFePO4 battery or only lead-acid?
Only if the listing names that chemistry, and only if you select it where the screen asks. The Depvko 30 A and the Rolokit 30 A say lead-acid only. The Topcloud 10 A and 30 A name LiFePO4 as a mode you set on the LCD. The AeternaSol 10 A names LiFePO4 on 12 V.
What does 100/15 mean?
On the Victron naming that the BlueSolar MPPT manual describes, 100/15 means a 100 V panel-voltage ceiling and a 15 A charge current. It is not 100 A. The SmartSolar in this set is the 100/15 at £61.60. Cold open-circuit voltage still has to stay inside that 100 V.
Is a 100 A controller at under £40 a larger controller?
Not on the evidence in this capture. The AeternaSol 100 A is £39.99 and 140 g, with 12 reviews. The Depvko 100 A is £19.54 and 290 g, filed under PWM controllers, with a UK review that says it is not MPPT.
What should I check on the panel label before two panels go in series?
Read the open-circuit voltage on each label, add the two figures, and then allow for cold weather, because Voc rises below 25 °C. That sum has to stay inside the controller's ceiling, such as 100 V on the SmartSolar 100/15 or 150 V printed on the Y&H 60 A listing.

Related pages

Solar panel

Solar charge controller

Best solar charge controller UK: which listing fits

Solar charge controller for a campervan, 15 W or 15 A

How to connect a solar charge controller, battery first

MPPT or PWM solar charge controller: voltage first

Sources

Public UK and manufacturer sources are listed below. Shelf prices and star lines are the amazon.co.uk figures captured on 19 October 2026.

  1. Victron Energy, BlueSolar MPPT installation (75/10 to 100/20) (retrieved 19 October 2026)
  2. Victron Energy UK, solar charge controllers (retrieved 19 October 2026)
  3. MCS MIS 3002 (2026), solar PV systems (retrieved 19 October 2026)
  4. Electrical Safety First, solar panels (retrieved 19 October 2026)
  5. Electrical Safety First, plug-in solar consumer guide (retrieved 19 October 2026)
  6. GOV.UK, fire and solar PV recommendations (retrieved 19 October 2026)
  7. IEA PVPS, Recommended Practices for Charge Controllers (retrieved 19 October 2026)
  8. Consumer Rights Act 2015, section 22 (retrieved 19 October 2026)