Charging toys from solar??

[sc-surfer]

Hi all,

I'm SURE this has been discussed but I'm not finding what I need. I'm hoping someone can point me to some good threads or resources!!

Here's what I want to do:

I spend a lot of time off grid, usually in Baja. My camper currently has 200w of solar on it and that is plenty to run lights, heater, charge phones/laptotps etc. However I want to be able to charge my other electric toys. I have a Onewheel, a Sur Ron e-bike and an electric Golf Cart/UTV. The Onewheel and Sur Ron are 60v and the golf cart is 48v. All are various lithium chemistries. I can add several more panels to the roof of my camper. Probably room for another 400w, for a total of 600w.

My question is this...What are my options for charging toys that are not 12v. My current charge controller can handle 12v or 24v systems only. I can run an inverter off of the house batteries and solar and then just plug in the chargers for each vehicle but that seems pretty inefficient and not very elegant. Does anyone make a solar charge controller that can handle this directly? Is there some other way? I gotta figure that with the emergence of inexpensive solar and the explosion of battery driven stuff that someone has figured out how to charge various voltage packs.

Any thoughts or ideas? Am I just stuck with doing the inverter to charger method?

Thanks for any thoughts or direction to other resources!!

Monte

 

[john61ct]

There are some boost SCs but usually 59-60V is the limit, and powerful DCDC converters at high voltages get very expensive.

Run a genset and plug your regular EV chargers in

 

[sc-surfer]

Thanks for the reply. REALLY trying to avoid a genset. I don't carry one as I'm full solar at this point. My truck is a diesel so I don't carry any petrol. Trying to avoid yet another fuel system with associated storage and maintenance issues. For me, the whole point is to use less petroleum. Given that I'm usually in a spot with ample sun I'm trying to harness that as much as possible.

 

[jonyjoe303]

you can find 1200 watt boost converters on ebay for about 20 dollars, some shipping from US suppliers. I have one that I use to power a laptop, from input 12 volt voltage, the output can go all the way to 90 volts. Just make sure you have a fan blowing at it if using with higher amps. You have to build your own case for it. These converters by there design are CC/CV chargers. I recommend you add a LED volt/amp meter(7 dollars) in-line if you plan to use them as chargers. The LED meter makes it easier to adjust the voltage/amp output, plus you can see charge status in realtime.



LED 100 volt 10 amp meter

 

[kansas]

Modern pure sine wave inverters are very efficient. There is an efficiency tax but it is modest. You may find it more suitable to use one than to invent a solution that is custom to your needs but has no other utility; you can run your TV, computer, and whatever within its power rating. Efficiency may be 90% and better, I think it is best near rated output, but you can talk to the mfr for use at lower load. This is probably not very different from efficiency of a boost converter--both are solid-state devices using similar technology.

Xantrex is a brand I have familiarity with and consider top-of-the-line. Cheapies are widely available (think Harbor Freight) but will not have the durability.

 

[john61ct]

The problem is, this use case charging EVs is an increase in total power required by an order of magnitude.

Almost like saying you want to run aircon off your battery bank charged by solar only.

Sure if you have a 40' long rig and spend many thousands on upgrading your solar and bank.

Otherwise, even dedicating **all** your current energy inputs to that one purpose, you will get an hour or two riding around from charging all day.

Practically you need a genset when away from mains. Diesel gensets exist of course, these days the smaller ones may even be quiet and inverter based, pure sine waveform is a must.

Won't be cheap of course.

______
Next critical point, make sure whatever charge source you use

has a reasonable algorithm for determining when the pack is Full and terminates charging automatically.

An adjustable HVC circuit could be rigged to cut off input to your charge source, CC stage only is fine for LI chemistries, in fact healthier than going all the way to top capacity.

 

[ZeroEm]

Just a thought, how much wind is there. Just thinking if close to the serf and lots of wind then a Wind generator may help.

 

[pullin-gs]

My etrikes charge with solar. One has 36V 18AH battery, other has 44V 8ah battery.
100W panel is secured on SW facing side of garage, Lithium charge controller (programmable for lithium batteries between 24v and 80V) is secured on inside of garage. After a ride, I plug up to the charger.

 

[john61ct]

Lithium charge controller (programmable for batteries between 12v and 80V)

Link please

>48V 18AH
so what, 2.5-3 days to recharge when well depleted? In ideal conditions

>44V 8ah
one full day

And that's not with feeding any other loads.

 

[John in CR]

Changing voltage output all the time on an "elegant" minimum loss solution sounds like a battery killing potential fire hazard waiting to happen. I say stick with simple. Build a properly sized lithium bank using auto salvage batteries from crashed electric cars to run all your lights stereo etc., as well as a good inverter to run any voltage charger you want now or in the future. Charge that battery bank using solar. This can be done very economically, and as an added bonus you get plenty of charge power for toys at any time of day or night so you're not reliant on the angle of the sun for sufficient power to your chargers.

 

[goatman]

andy kirby shows his solar charging trailer set-up

https://www.youtube.com/watch?v=L60jgjIIqFU

and his straight from panel to ebike set up

https://www.youtube.com/watch?v=IGO8HSw9IME

 

[pullin-gs]

Lithium charge controller (programmable for batteries between 12v and 80V)

Link please

>48V 18AH
so what, 2.5-3 days to recharge when well depleted? In ideal conditions.

>44V 8ah
one full day

And that's not with feeding any other loads.

Your assumptions/numbers are way off....charger/panel delivers 2.0 amps to 44V pack throughout charge cycle.
*) To charge my 8AH pack usually takes no more than 3 hours when depleted (I rarely discharge past 10% capacity).
*) W=V*A advice: Do you need to charge faster? Add another panel or two! Charge controller will switch 300/600 watts depending on model.
*)I typically ride no more than 10 miles a day running errands or short trips.....charge time takes around 1.5 hours typically in Florida sun.
*) As for needing power for other loads?? See W=V*A note above.

This is a fine solution which addresses the OP's topic of interest ("Charging toys from solar") where voltage levels change. Charge rate was not even mentioned.

Parts list/cost:
Richsolar 100 Watt Polycrystalline 100W 12V: $75 delivered
https://www.amazon.com/Richsolar-Polycrystalline-Efficiency-Module-Marine/dp/B07DNP14JY?ref_=ast_sto_dp
MPPT "boosting" Solar Charge Controller: $33 delivered
https://www.youtube.com/watch?v=omAhsQqwWSo&t=108s
https://www.ebay.com/itm/313232203226

 

[sc-surfer]

thank you pullin-gs. That is the exact type of unit I was seeking. Just didn't know what to call it.