Thunder 20A DC-DC Battery Charger w/ Solar Regulator TDR02020Designed to be versatile enough for use across a range of different vehicles, the Thunder 20A DC-DC Battery Charger with Solar Regulator is the smart way to keep your auxiliary battery charged.The device employs a unique pulse-charging algorithm, sophisticated enough that it can determine the ideal charge for many battery types (excluding lithium batteries). Make managing your dual battery setup easy and hassle-free with this state-of-the-art charger.
Thunder 20A DC-DC Battery Charger w/ Solar Regulator TDR02020Designed to be versatile enough for use across a range of different vehicles, the Thunder 20A DC-DC Battery Charger with Solar Regulator is the smart way to keep your auxiliary battery charged.The device employs a unique pulse-charging algorithm, sophisticated enough that it can determine the ideal charge for many battery types (excluding lithium batteries). Make managing your dual battery setup easy and hassle-free with this state-of-the-art charger.
Thunder 20A DC/DC Charger
Thunder 20A DC-DC Battery Charger w/ Solar Regulator TDR02020Designed to be versatile enough for use across a range of different vehicles, the Thunder 20A DC-DC Battery Charger with Solar Regulator is the smart way to keep your auxiliary battery charged.The device employs a unique pulse-charging algorithm, sophisticated enough that it can determine the ideal charge for many battery types (excluding lithium batteries). Make managing your dual battery setup easy and hassle-free with this state-of-the-art charger.
Thunder 20A DC-DC Battery Charger w/ Solar Regulator TDR02020Designed to be versatile enough for use across a range of different vehicles, the Thunder 20A DC-DC Battery Charger with Solar Regulator is the smart way to keep your auxiliary battery charged.The device employs a unique pulse-charging algorithm, sophisticated enough that it can determine the ideal charge for many battery types (excluding lithium batteries). Make managing your dual battery setup easy and hassle-free with this state-of-the-art charger.
in 5 offers
The lowest price for Thunder 20A DC/DC Charger right now is $169.00 at Frankies Auto Electrics, compared across 5 retailers.
The all-time low was $89.00 on 28 Nov 2025 — today's price is 90% above the lowest ever. It has been notably cheaper before — worth setting a price alert.
Prices last updated 22 Sept 2026.
Last updated at 22/09/2026 18:50:45
Thunder TDR02020 20A DC-DC Charger With MPPT Solar Regulator – Frankies Auto Electrics & Car Audio
Delivery $15.95
Thunder Tdr02020 20a Dc-dc Charger With Mppt Solar Regulator
Delivery $4.50
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Thunder 20 Amp Dc-Dc Charger - TDR02020
Delivery $20
Thunder 20 Amp Dc-Dc Charger
Delivery $20
THUNDER 20A DC TO DC CHARGER SOLAR REG V2
Delivery $16.65
originally posted on ebay.com
This DCDC charger is fantastic. Installed and works really well. The connections were a little hard to work out the neatest way to install and the factory terminal covers are basically useless, but other than that its fantastic! I used thick glue filled heatshrink and split conduit for extra insulation/ electrical separation. Definitely recommend it and will buy another for hw camper battery.
originally posted on ebay.com
Awsome product, can't fault it. Have one in my 4x4 running for 6 years without fault, bought a second one for my work car.Why pay 700 bucks for a red arc when this does the same job for just over 200 bucks. Can't beat it
originally posted on ebay.com
This DCDC charger works perfectly to regulate the input from my 300w solar panel to rapidly charge up my 100ah LiFePO4 battery in just a couple of hours - even at just the device's maximum of 20a, all the while maintaining the charge in my Lead-Acid crank battery. At this price, I highly recommend letting the built-in MPPT charge controller do all the work, over most charge controllers that are available on the market.
Thunder TDR02020 20A DC-DC Charger With MPPT Solar Regulator – Frankies Auto Electrics & Car Audio
Delivery $15.95
Thunder Tdr02020 20a Dc-dc Charger With Mppt Solar Regulator
Delivery $4.50
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Thunder 20 Amp Dc-Dc Charger - TDR02020
Delivery $20
Thunder 20 Amp Dc-Dc Charger
Delivery $20
THUNDER 20A DC TO DC CHARGER SOLAR REG V2
Delivery $16.65
This DCDC charger is fantastic. Installed and works really well. The connections were a little hard to work out the neatest way to install and the factory terminal covers are basically useless, but other than that its fantastic! I used thick glue filled heatshrink and split conduit for extra insulation/ electrical separation. Definitely recommend it and will buy another for hw camper battery.
Awsome product, can't fault it. Have one in my 4x4 running for 6 years without fault, bought a second one for my work car.Why pay 700 bucks for a red arc when this does the same job for just over 200 bucks. Can't beat it
This DCDC charger works perfectly to regulate the input from my 300w solar panel to rapidly charge up my 100ah LiFePO4 battery in just a couple of hours - even at just the device's maximum of 20a, all the while maintaining the charge in my Lead-Acid crank battery. At this price, I highly recommend letting the built-in MPPT charge controller do all the work, over most charge controllers that are available on the market.
Great value and works better than expected. Solar charge works well with 120w solar system on cloudy day, had no power issues camping for 3 days with 60L fridge, lights, 12v shower and charging devices from battery. No noise or heat from the dc charger.
Awesome DC charger - switches between car input and solar seamlessly. Never have to worry about it. Solidly build and it uses lugs instead of inbuilt cables like some other devices I was looking it which is a definite plus.
Arrived in good condition. Looks well made. Tests looks like all is working. Havent given a good test run yet.
Thunder works great with modern smart alternators, charging my caravan battery and looking after my vehicle battery at the same time (not letting it go flat). A bonus with the Thunder is the built in solar input so you do not need a solar regulator as its built into the Thunder. This unit is robust with clear readout.
Very detailed listing made thigs so easy to decide this was the right unit for the job fantastic price. Am that happy with it i will be buying a second one for my brothers car. On top of that very happy with the very very quick postage. Not one bad thing to say. Cheers
I absolutely love this gadget and here's why. Bought this for use in my camper van conversion to charge two 920Ah 12V AGM house batteries while driving. In a word, this is an AWESOME piece of gear that truly does what it claims. Run the fridge while and charge the batteries while driving? No problem! It's rated at 20A and it truly is. It did take a while to get to the USA [thanks to the wisdom in our currently ummm... unusual political system] but all is well. No worries about the unit itself. Took it on our first long-haul trip today from Tampa, FL to St. Augustine, FL. Ran the house batteries down a bit while keeping the fridge on overnight [no shore power]. Started the engine and the unit snapped to attention immediately sensing the low-charge state [I believe it ... MoreI absolutely love this gadget and here's why. Bought this for use in my camper van conversion to charge two 920Ah 12V AGM house batteries while driving. In a word, this is an AWESOME piece of gear that truly does what it claims. Run the fridge while and charge the batteries while driving? No problem! It's rated at 20A and it truly is. It did take a while to get to the USA [thanks to the wisdom in our currently ummm... unusual political system] but all is well. No worries about the unit itself. Took it on our first long-haul trip today from Tampa, FL to St. Augustine, FL. Ran the house batteries down a bit while keeping the fridge on overnight [no shore power]. Started the engine and the unit snapped to attention immediately sensing the low-charge state [I believe it was somewhere around 75%]. Drove for four hours also running the fridge and at the destination 5 hours away, it was topped off at about 94%. On the way back, charge was an initial 80% and reached 100% about an hour from home [fridge off]. I suspect you will have similar results. Product is very high quality and a snap to install. Two 12V circuit breakers [one in, one out] and it's good to go. Unlike diode steering isolators, this is a true charger and will maintain a proper full charge from your alternator. Mineis in a 2018 Ford Transit and has one of those duty-cycled alternators to help improve mileage. No worries with this unit in dealing with that kind uf unusual circuitry. Worked like a champ. So while the isoaltors are very simple to install and much cheaper to buy, neither battery in your rig will be fully charged because of the diode voltage drop [about 0.7V less than full charge]. With this unit, all batteries reach full charge and will last MUCH longer as a result.
Solar input way to high and pulse amplitude peak varying up to 17 volts. DC to DC from alternator good. Also poor separation of terminals.
