BCDC Charger for Use with Solar Power, Starter Batteries and AGM/Lithium
Updated 03/10/2026 | Published 03/08/2026
Question:
Hello, I have a converted school bus and I want to find a battery charger/maintainer to keep my starter batteries charged. I want to connect it to the solar system. I have on the bus. The solar system is 12 V. So I’m looking for a 12 fold DC DC charger/maintainer the solar system batteries are lithium. The starter battery batteries are AGM. Can you suggest the right product?
asked by: Andrew A
Helpful Expert Reply:
Hey Andrew, you would want the Redacr In Vehicle BCDC part # RED36TR which is compatible with the setup you have. This can use solar power as an input as well as is compatible with lithium and AGM batteries. How many solar panels do you have?
(click to enlarge)
Product Page this Question was Asked From
Redarc In-Vehicle BCDC Trailer Battery Charger - Dual Input - DC to DC - 12V - 12 Amp / Solar 40 Amp
- Battery Charger
- Battery Charger
- RV/Camper
- Trailer
- 12V
- 24V
- Charges and Maintains
- AGM
- Calcium
- Gel
- Lead Acid
- Lithium
- Solar Panels to Auxiliary Battery
- Vehicle Battery to Auxiliary Battery
- Smart Charge
- Trickle Charge
- Redarc
more information >
Featured Help Information
Instructions
Continue Researching
- Q&A: Can Vehicle 7-Way Charge Batteries for Trailer Winch
- Q&A: Recommended Wiring for RedArc BCDC Charger Used for Auxiliary Battery to Power Inverter
- Article: What RV AC Will Work With Your Setup? Avoid Costly Mistakes Before You Order
- Q&A: Recommended Solar Panel for a Redarc In-Vehicle BCDC Trailer Battery Charger
- Article: Trailer Wiring Diagrams
- Q&A: How do I Trickle Charge a Battery on my Trailer
- Article: How to Charge a Trailer Battery While Driving: 3 Common Problems (And How to Fix Them)
- Q&A: How to Charge Battery for Fridge Using Alternator and Solar Power
- Q&A: Availability of Dump Trailer Controller
- Q&A: Does Install of Victron Orion XC RV Converter Ground to Battery and Chassis
- Article: Routing the Power Wire for a Trailer Wiring Harness
- Article: Towing a Trailer? Let's Talk About Brake Controllers
- Article: Converting Your RV Water Heater to Tankless
- Article: The Best Towing Mirrors
Norman
3/10/2026
Andrew: I would be concerned about this device meeting your needs. I really have a lot more experience in the marine world than with land products. In any case I used this product in a tow vehicle > trailer setting. The main goal was to have increased charging while towing from my Ford truck (which drops its alternator output once the starting battery is charged. ). This device is designed for a system with a separate starting battery and house battery bank. It allows the start battery to charge followed by the house battery using a 3 stage charging cycle which is much better for deep cycle lead acid (which includes AGM) batteries. I did learn after buying it that the solar input works much better than the previous solar conditioner we had (when you say you have a 12 V solar system I strongly suspect you have a conditioner which you will want to remove if you use this device which takes full voltage from the solar panel and determines the best output voltage for the batteries). SUMMARY: Strongly consider adding a deep cycle house bank then your starting battery is used only for starting the bus (and is preferably a starting battery design which is made for rapid discharge over a short time).