How to charge the Ryobi 18v and 40v batteries directly from solar

[BenQ]

1. 100 watt monocrystaline panel
2. Renogy Rover Mppt 40 amp (you could get by with 20amp I’m sure)
3. iMax B6
4. 2x 6v Trojan t-105 flooded lead acid (you could probably use any other 12v battery)
5. Old ryobi flashlight w/o the bulb (or any other old tool out of the trash or on OfferUp)
6. The boost converter that Andy from off grid garage used to charge his big battery from a “mystery” 12v battery would charge your 40v battery.

 

[Supervstech]

Very simple solution get the ryobi 40v battery charger. (not the rapid charger) Cut off the 110v power supply get a

MPPT Boost Solar Panel Battery Regulator Charger Controller 24V-72V $40 on eBay connect it to your solar panel and set the charge controller output to 41.7v connect the power supply cord coming from the ryobi charger to this adustable voltage solar controller output and you will have a Solar Roybi 40v battery charger.​

I have the charger I got with my 5.0 battery, I will look over the specs on it and see if it would accept that low a voltage… I doubt it.

 

[Supervstech]

1. 100 watt monocrystaline panel
2. Renogy Rover Mppt 40 amp (you could get by with 20amp I’m sure)
3. iMax B6
4. 2x 6v Trojan t-105 flooded lead acid (you could probably use any other 12v battery)
5. Old ryobi flashlight w/o the bulb (or any other old tool out of the trash or on OfferUp)
6. The boost converter that Andy from off grid garage used to charge his big battery from a “mystery” 12v battery would charge your 40v battery.

Does this work safely? I would think this bypasses the BMS… it certainly bypasses the temp sensor info.

 

[Supervstech]

Very simple solution get the ryobi 40v battery charger. (not the rapid charger) Cut off the 110v power supply get a

MPPT Boost Solar Panel Battery Regulator Charger Controller 24V-72V $40 on eBay connect it to your solar panel and set the charge controller output to 41.7v connect the power supply cord coming from the ryobi charger to this adustable voltage solar controller output and you will have a Solar Roybi 40v battery charger.​

Ok, my charger states 120V AC INPUT, 72W I do not believe the charger would accept 41.7V dc input and charge the battery…

 

[BenQ]

Ok, my charger states 120V AC INPUT, 72W I do not believe the charger would accept 41.7V dc input and charge the battery…

If you opened it up and took out the guts then soldered the positive and negative terminals to the 41.7v dc input like I did with my flashlight it would work.

 

[BenQ]

Does this work safely? I would think this bypasses the BMS… it certainly bypasses the temp sensor info.

Yeah it works great for the 18v b/c the imax b6 has custom charge settings. The BMS still works, but yes it might bypass the temp sensor. The charge settings on the imax are super helpful in that regard.

 

[NwCali]

I own many of their battery tools...

I agree with others, their not very robust..... I think its most likely a crap thermal management thing...

 

[RDCanada]

I have a potentially slightly easier and more efficient approach to charging your 40V, that doesn't involve inverting to AC.

Ryobi makes a charger model OP403A for the 40V that isn't a car charger, but it does use a detachable AC adapter that outputs 42V DC. You could ditch the AC adapter and just get a boost circuit to step up or down the voltage from your solar panel to 42V. The benefits, as I see them, are:
1) No converting to AC and back
2) A DC-DC step up boost circuit is probably cheaper than an inverter and it's certainly smaller. There are a million of them on ebay and aliexpress.
3) You still get to rely on the Ryobi stock charging circuitry. Also, I doubt that the charger body unit is actually relying on the AC adapter being exactly, 42V for voltage regulation. I'm sure there is also some voltage regulation inside the charger.

 

[Kcdaniels]

I have eight batteries for my Dewalt cordless tools. Most of them are 5amp with the oddball 4amp. Those are the 20v batteries. I have a 60v 9amp battery also. I charge them in my trailer using the Dewalt charger connected to my Xantrex 1000 watt MSW inverter. I do that during the day so that the solar is providing power instead of the batteries. I'll sometimes charge the batteries off of the inverter that came in my F-350.

When I'm on the trail in my side-by-side, I bring my Dewalt sawzall and chainsaw with plenty of batteries so I don't have to recharge. Only once have I gone through all the batteries. There were so many trees blown down across the trail that it was going to take all day to clear a 1/4 mile of the trail, so we called it a day and went elsewhere. If we had a gas chainsaw we would have run out of fuel long before we cleared enough of the trail to make it worthwhile.

I like to keep things simple. More batteries. But I might get the Dewalt 12v Vehicle Battery Charger so I can charge from the port in my side-by-side. The charger would have been useless in the above situation since the temperature was in the 20's. The charger would have told me to pound sound if I tried to charge a battery in those temps.

So if I'm reading this right your charging with a Modified sine wave inverter ? This is what I have in my truck solar setup but wasn't sure if it was ok to use the MSW inverter to charge my Rigid batteries...

 

[Tdkbama]

Here's an adapter for Ryobi batteries that I made to be 3D printed ( https://www.prusaprinters.org/prints/39638-ryobi-one-18v-battery-charge-adapter-for-solar-pow ). I figured out how to put the Ryobi batteries into charge mode. I have used a Victron solar charger to charge them (

) and I have used the Megasolar folding solar panel's 20V regulated output to charge the battery directly (

)

Chris, This is a great idea and excellent video. I’ve purchased the same components you’ve used and connected as instructed, but something’s not working right. I’m getting intermittent output on the load side from Victron. Before I connect that DC/DCconverter, I measure 20.6 V on the Batt side of the MPPT. Sometimes, I’m seeing the same 20v on the load side. However, sometimes, after connecting the DC/DC converter to the Victron I’m seeing little or nothing on the output from the Victron or the converter. It’s jumping around in the 0-2 v range, sometimes not showing any output at all. If I disconnect the converter and reconnect, sometimes it stays on and shows 20v, but it’s cutting off shortly afterwards. If I connect direct from the Battery, using your adapter, to the DC/DC converter, it works great every time. Just not consistent. Just wondering if it’s a setting on the Victron. Would it be possible to see the VictronConnect 100/20 parameters that you set? Thanks very much for this video and your help.

 

[Tdkbama]

Update. Being a noob, I didn’t realize the load side actually had to have something pulling current for the output terminals to register something passing through. It works great. Chris this design works great on the 18v and I appreciate your help.