Can you run a battery charger through a solar charge controller?

[OffRoadRN]

I have a diy 12v lithium set up that I want to add a solar charge controller to. Currently, I charge the battery with a 4.5 amp battery tender through an SAE port. Can I put a charge controller between this port and the battery and then use the same port for either solar panels or the battery tender, or should I have separate inputs for the respective charging methods? I attached a basic diagram of how my battery is wired.

I am planning on using a Renogy wanderer, does anyone have a suggestion of something better? Are there any MPPT chargers that small? Originally I was planning on using a Renogy rover but it was too large. I don't want to spend Victron money.

Thanks!

 

[Mattb4]

You can use a common battery connection for outputs of the battery charger and the SCC. Even if you used separate wires eventually they become common once they reach the battery.

 

[DVD]

Agree with above. I do see any reason to run your tender through the SCC. I’d run the solar through the SCC and the tender battery direct. If you’re running a monitor, use the P- connection on the shunt as if it were battery negative and connect ONLY the battery negative to the B- post on your shunt. You’ll get the charge reading of the combined tender and solar.

 

[OffRoadRN]

Agree with above. I do see any reason to run your tender through the SCC. I’d run the solar through the SCC and the tender battery direct. If you’re running a monitor, use the P- connection on the shunt as if it were battery negative and connect ONLY the battery negative to the B- post on your shunt. You’ll get the charge reading of the combined tender and solar.

Ok thanks for the input. This was my inclination but just wanted to double check. I chose SAE for the input since that’s what my battery tender connection is. For the solar input should I use xt60 or an Anderson outlet? Or would another sae outlet be fine?

 

[MisterSandals]

For the solar input should I use xt60 or an Anderson outlet? Or would another sae outlet be fine?

How many amps are you expecting to have. I think the limit for an SAE is about 12A (~150W).

If it were me, i'd use the same type of plug on everything so that a few adapters/connectors in spare would provide a lot of flexibility.
Note that XT-60 requires soldering but its a good standard. I'd make a couple Y connectors, gender bender adapters (male to male, female to female...) and you can reconfigure or add to with ease.

 

[DVD]

Yep! Agree with all the above regarding adapters, gender reversers, etc. Can’t have too many.
I’m not a big SAE fan. XT-xx are more robust imo. No risk of polarity mismatch.
Only issue I’ve come across is weather proof sidewall mounting. I haven’t found a good weather proof XT

 

[OffRoadRN]

I’m not a big SAE fan. XT-xx are more robust imo. No risk of polarity mismatch.
Only issue I’ve come across is weather proof sidewall mounting. I haven’t found a good weather proof XT

The only reason I used SAE is because that’s what the battery tender uses, and I wanted to avoid an adapter.

 

[DVD]

SAE is very common and nothing to necessarily avoid. Many RV have input ports for portable solar panels and I think all are SAE. I just don’t think they’re that well suited for many applications.
Just watch your polarities and current. There’s a variety of wire gauge used on SAE. I’ve seen as small as 16, so if you stay with SAE check that you’re using 12 or larger all the way through.

 

[OffRoadRN]

SAE is very common and nothing to necessarily avoid. Many RV have input ports for portable solar panels and I think all are SAE. I just don’t think they’re that well suited for many applications.
Just watch your polarities and current. There’s a variety of wire gauge used on SAE. I’ve seen as small as 16, so if you stay with SAE check that you’re using 12 or larger all the way through.

I bought 10 gauge, thanks for the info!

 

[Crowz]

If your planning on putting the charge controller inside the box I would make it a very small amp wise charge controller. The larger the controller the more heat it makes and inside a sealed box to many amps thru the controller isn't going to end well.

10 amps max I would imagine to be safe. I use 20's inside a box like that but they never do more than 5 amps with the panel size I have on them.

This is the ones I use.

https://www.amazon.com/gp/product/B008HWSA78/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

They are pwm not mppt but they do fine for a single battery if it can be handled by a low amp charge.

 

[OffRoadRN]

If your planning on putting the charge controller inside the box I would make it a very small amp wise charge controller. The larger the controller the more heat it makes and inside a sealed box to many amps thru the controller isn't going to end well.

10 amps max I would imagine to be safe. I use 20's inside a box like that but they never do more than 5 amps with the panel size I have on them.

This is the ones I use.

https://www.amazon.com/gp/product/B008HWSA78/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

They are pwm not mppt but they do fine for a single battery if it can be handled by a low amp charge.

So a 30 amp controller with 200 watts of panels will be too much for this set up? The box is only temporary until I finish building a drawer system, at which point it will be taken out of the box and installed into the truck.

 

[MisterSandals]

This is the ones I use.

https://www.amazon.com/gp/product/B008HWSA78/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
They are pwm not mppt but they do fine for a single battery if it can be handled by a low amp charge.

But this will not work for OPs 48V solar panel!

>Maximum solar voltage : 30V（12V System） , 55V（24V System）

 

[Crowz]

So a 30 amp controller with 200 watts of panels will be too much for this set up? The box is only temporary until I finish building a drawer system, at which point it will be taken out of the box and installed into the truck.

It might be ok but when I was putting charge controllers in poorly or non ventilated cases back in the day I had a one melt the side of the plastic bin I had the setup in. I don't remember the amperage of it but I think it was a 40 amp with 500 watts of panels.

The box was in the shade but it was in the high 90's temp wise outside at the time.

 

[Crowz]

But this will not work for OPs 48V solar panel!

>Maximum solar voltage : 30V（12V System） , 55V（24V System）

I'm not seeing the size of the panels listed in this thread. Which post is it?

 

[OffRoadRN]

I'm not seeing the size of the panels listed in this thread. Which post is it?

I’m looking at portable 200 watt offerings, probably something cheap like the allpowers sp033.

 

[chrisski]

My portable panels came with These Anderson Pole 45 amp connectors. I found them very handy to set up and crimp.

The SAE cables do not have a crimp option I can find but always a cut and splice option. I don’t like that because of voltage loss.

 

[Crowz]

I’m looking at portable 200 watt offerings, probably something cheap like the allpowers sp033.

Good looking panel with decent reviews and 18 volts will work with about any charge controller.

Peak Power: 200W ± 5%


Open Circuit Voltage (Voc): 22.2V Short Circuit Current (IOC): 12 A


Maximum Power Voltage (Vmp): 18 V Maximum Power Current (Imp): 11A


Solar Energy Conversion Rate: 19%-22%


Operating Temperature: -20 ~ 60 ℃/ -4 ~140 ℉

I noticed mixed reviews on watts output wise but I have a feeling its the low voltage of the panel 18V vmp.

I had a long post at this point showing what models worked well with it and which didn't from those reviews then I got to the reviews that focused on build quality. I don't think I would go with this one.

Wires pulling out of the bad material on the back of them and no way to get to the connection point on the panel because of the canvas covering.

Several said it worked the first time and then failed or worked the first time and got weaker each time they unfolded them to use again.

I'd go with something else if it was me after reading all of those reviews.

 

[OffRoadRN]

Good looking panel with decent reviews and 18 volts will work with about any charge controller.

Peak Power: 200W ± 5%


Open Circuit Voltage (Voc): 22.2V Short Circuit Current (IOC): 12 A


Maximum Power Voltage (Vmp): 18 V Maximum Power Current (Imp): 11A


Solar Energy Conversion Rate: 19%-22%


Operating Temperature: -20 ~ 60 ℃/ -4 ~140 ℉

I noticed mixed reviews on watts output wise but I have a feeling its the low voltage of the panel 18V vmp.

I had a long post at this point showing what models worked well with it and which didn't from those reviews then I got to the reviews that focused on build quality. I don't think I would go with this one.

Wires pulling out of the bad material on the back of them and no way to get to the connection point on the panel because of the canvas covering.

Several said it worked the first time and then failed or worked the first time and got weaker each time they unfolded them to use again.

I'd go with something else if it was me after reading all of those reviews.

Thanks for the info!