mobile charging w/ modified sine, from lead acid

Obviously not ideal, but I'm considering bringing enough lead with me on the road (in a car) to invert to 120v for 'camping', and to run my meanwells to charge the bike @ ~100v DC. Kinda debating this as I should have a bigger inverter and could instead primarily charge direct from campground hookups etc. The only catch Is I'm looking at about 25 pieces of large acreage in several states that I'll use the bike to surveil, and it would be best for my lipo to charge right before the ride- I didn't plan to always leave directly from a campground or even use one to camp every day, so kinda leaning towards the mobile charging.

Side question, how many amp hours will be needed from the 12v lead acid bank for inverting and charging about 7ah into the 100v lipo? I'm thinking like 60ah, before losses!!! You should probably have at least 200ah of lead in that case, for just one charge?!?


I only found one mention on the web or on the forum of running powersupplies with only modified sine inverters.
Apparently it worked? https://endless-sphere.com/forums/viewtopic.php?f=3&t=41572&start=450

Does anyone know if there's any issue of longevity etc without pure sine for the chargers?

I mean, they're just taking it back to DC anyway right? So far there isn't anything I've had a problem running with modified sine- ac motors just tend to make a little noise.

I think the simplest solution would be to take a gasoline generator along. I have a 2000w gen that I got from Harbor Freight that runs fairly quietly and doesn't weigh much more than a 12v deep cycle battery. The only thing I don't like about it is that it doesn't have a prime bulb. When new it took about 100 pulls on the cord before gas finally made it to the cylinder. Since then it starts easily as long as I don't let it run out of gas.

Hwy89 said:

?.....The only thing I don't like about it is that it doesn't have a prime bulb. When new it took about 100 pulls on the cord before gas finally made it to the cylinder. Since then it starts easily as long as I don't let it run out of gas.

Click to expand...

If it runs out again, try blowing in the gas tank ...low pressure for a few secs usually does it . :wink:

Hillhater said:

Hwy89 said:

?.....The oilyy thing I don't like about it is that it doesn't have a prime bulb. When new it took about 100 pulls on the cord before gas finally made it to the cylinder. Since then it starts easily as long as I don't let it run out of gas.

Click to expand...

If it runs out again, try blowing in the gas tank ...low pressure for a few secs usually does it . :wink:

Click to expand...

If putting your mouth where gas might come out gives you the heebie jeebies you might try a shot or two from a can of Quick Start starting fluid aerosol spray ether through the intake. :lol:

Good points, thankyou.

I guess rather than spend >400$ for a second camp battery, mod inverter, and 50a 12v charger,

or even rather than spend >400$ for a more flexible/capable 2kw generator that'll still be hardpressed by the meanwells,

I'll probably ramp down my charging amperage and use the 800w genny and/or 800w mod inverter/ 100ah bank that I already possess- Charging would just take longer and a full charge wouldn't be reasonable from the 12v bank. Since no-one screamed "NOOO", I'll assume the modified sine inverters aren't a definite enemy of the ac to dc chargers, though I'd probably only use it in a pinch anyway.

I already have a dual fuel 4kw genny, but I'm not hauling that around just to charge the bike. I almost would blow money on a compact 2kw genny but they're still kinda big and barely adequate for the charger as-is. I hate using an obnoxious genny at all, when already driving around in a huge powerplant that is a car. If I had an older vehicle I'd just look at driving a nice generator head with the vehicle motor.



Also thought about building a 48v bike for my 16ah multistar pack, but honestly it's similar watthours to charge, wouldn't save much weight, and wouldn't be much more efficient than my current 100v build.
Maybe I shouldn't even take the bike- gonna test run all this before heading cross country.

Gotta find out simple ways of limiting amperage for the charger.
I might loop the gophert adj lab supply in with the meanwells to limit 0-10a, but thinking there might be a simpler way with less 'overhead'?

Hillhater you just gave me a good idea. I'm going to rig up a second gas cap with a shrader valve and add a little pressure with my tire pump. Wow why didn't I think of that sooner.

Yup nice one, I never thought of that either. My little HF 800/1000w gives a little trouble too.

What about just like a bladder that fits over a vented cap? Leave it on and just press/squeeze? My problem might be gunked carb do to unuse, but trying some pressure first shouldn't hurt anything


edit// turns out that wouldn't be really easy with the huge unvented cap on mine. . . . But it was fairly easy to work the rubber line off the petcock and apply pressure. Lung pressure of ~2psi didn't do it, but a blast from the air nozzle did- pretty cool for what was likely gunked up jets. Maybe if a lawnmower type primer is ever necessary, something like it could be worked into the hose between carb and petcock?

So I wired in my little gophert lab supply with the meanwelss and have a small problem.

I can only get it to stay running if starting at it's max amps (~10a). It limits the meanwells fine from their >14a, and I can patiently crank it down an amp at a time from there. I did so on grid power, and turned chargers off just long enough to swap over to the 800w generator. It rans everything fine @ 5.5a. The problem is that even though I was able to restart the chargers @ that 5.5a, after I waited a while and re-tried, the gophert went right back to OC protection. Going back to grid, I was able to repeat the process of starting @ 10a and slowly lowering it.


SO I guess the array won't work for my little genny OR inverter. (without first 'warming it up' on a 20a circuit lol)


Where's a good place to buy a 100v 5a charger (not bmsbattery)? I'll just get one as a spare and for travel/portability.

Edit/// Aliexpress only had two reasonably priced: 3.5a for ~60$ shipped and the one I ordered- 6a for ~100$ shipped.
https://www.aliexpress.com/item/600W-110V-230VAC-72V-87-6V-DC-6Amp-Aluminum-Casing-LiFePO4-Battery-Charger-Electric-Vehicle-Charger/32307789748.html?spm=2114.01010208.3.10.O4lC7j&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10065_10151_10068_10130_10136_10137_10060_10138_10155_10062_10156_10154_10056_10055_10054_10059_10099_10103_10102_10096_10148_10147_10052_10053_10142_10107_10050_10051_10084_10083_10080_10082_10081_10178_10110_10111_10112_10113_10114_10181_10078_10079_10073_10070_10123_10124,searchweb201603_2,ppcSwitch_7&btsid=5c038598-fe3c-474a-bc9f-4f15b51c50e4&algo_expid=dad3c5f3-adb2-4853-afe7-1b1740babec8-1&algo_pvid=dad3c5f3-adb2-4853-afe7-1b1740babec8
It'll take a little longer to charge even when there's access to a 20a circuit (campground etc), and I have no clue if I can (or even should try) turning down the voltage for my charge voltage of >4.15v /cell. Woulda been nice to successfully mod the meanwells- oh well!

FWIW, the HLG meanwells, which are potted weathersealed LED PSUs, have adjustable voltage and current, and can be seriesed for higher voltages, and paralleled for higher currents.

They're not exactly light because of the potting, but they're sturdier because of it, and fanless. I've got some of the HLG600 series, and use a couple in parallel for 58v 24A charging off a single wall outlet. I haven't personally tested it with the other pair in series with those yet, but that's how they had been used before I got them, for fast charging a 120v pack.


So you could series an HLG with the other MW types, and let it do the current limiting part, and it should work.

Once I find my open-cage MWs, that I think are the hiccup limiting type, I can test that theory. I already know those open cage MWs can work in series with my Sorenson lab PSU used as teh current limiter.

Thanks for the reply AW; I just now saw it but cross-thread posted not too long after- was thinking the same but curious about tech detail of the hlg current adj feature . (posterity- other thread https://endless-sphere.com/forums/viewtopic.php?f=14&t=87967 ) I got no clue though why my gophert needs to start on full amps (already limiting MW by 30%), but can successfully limit to <30% of the MW max.

Highly considering a ~100$ hlg so to still have full 14a charge feature with full AC supply on the same charger though!

I've been looking into 'Mobile Charging' myself
I have read that BC basically outlawed gasoline bicycles, you need a license and insurance, I doubt that insurance companies insure a gas bicycle. Either way, it got me thinking. Gas Bicycles do stick out like a sore thumb, they are noisy and generate a lot of noise. Which is why I paid extra to go electric. No issues here in Alberta.

I found a $125 used generator rated for 1300W that is 18"Lx15"Wx17"H and weighs 50 lbs. That is a lot of weight to be hauling around. No mention of amp output on the 120V system, calculations say 11A. My 120V Meanwells use up 4A from the wall, and put out 16A whether its 1, 2, or 3 Meanwells in series. Could even split the battery pack up for even faster charging.

The Honda generators are ultra quiet, but expensive.

I've never been around many generators before, once a year there is a food truck running a gen that I happen to walk by. Usually the use big ole gen's 5kw or more.

Question is, how much if any does a generator need airflow?

Was thinking could just enclose the gen, maybe put a few high flow mini fans to suck fresh air in and over the gen, and fans to expell the hot air. From my searching it looks like its doable.

The next thing is to find a way, or purchase an ultra small yet high enough watts, say 5A at 120V to use.
I dont really want to build one from scratch, so I am willing to go a bit bigger and a little heavier. The enclosure with its pusher and puller fans will be neat to build.

So while your riding your ebike, you can have a generator on the back trailer charging up your backup battery, while your using your current battery.

I think about my old 24Ah battery where I could ride 35km at 30-35kph. Now make a larger battery lets say 75Ah and that now becomes 100km in 3 hours.

Now that 75Ah battery, would be charged at 16A in about 4.5 hours with one charging setup.

Now I forgot something here. That $125 1300W charger off of Kijiji is putting out 11A, which means I could have two or even 3 charging setups! Which would charge a split battery in half or a third of the time. Take that 75Ah pack charging now at 32A is 2.34 hours (2 and one thirds of an hour) This puts the bike on continuous riding capability with short 5 minute stops to swap out battery and hook up for charging.

An extra 50 lbs, on a rear bicycle trailer with a generator that is 18"Lx16"Hx16"W, enclosed with fans for airflow. It would be a bit quite the sight to see.

Of course this is used for long distance riding something like a 975km ride through the mountains.

I found a neat little unit its a Honda EX800
dimensions are LWH 16.5x11x15.4
dry weight is still 50.7 lbs
5.8 to 6.7A output on 120V

Im gunna have to see how many amps is pulled from the wall outlet when I charge up two batteries at full power. Im guessing two charging stations is 8A, as one is 4A.

The weight of the gen is a little concerning to me but I used to weight 325lbs, but I gained 60 lbs and am now at 388lbs from the gym scale so I think the benefits of having on demand power, without having to hunt down one outlet might be worth it, especially the long trips where there is nothing for 150-200km when the total range of 75Ah is 100km. Golden BC to Revy is 150km, thats about the longest trip between 2 major townships from Calgary to Vancouver.

I will have to ponder it all some more for my long distance "Hybrid ebike" trip Calgary, AB - Victoria, BC trip.
I think a bonus for having a generator on a trailer, is you can go into the bush and setup a "base camp" and tryout all the trails in and around the area. I think of a place near me called Mclean Creek, which is by Bragg Creek only a stones throw from Calgary. Mclean Creek is a massive OHV area where you can camp, dirt bike, take your truck or suv offroad and basically have fun! I've taken a few of my Jeeps out there, YJ, '88 XJ, '01 XJ and its a blast, I think ebiking would be neat to try as there are dirt bike trails, jeep trails which I like to call goat trails because you can take a YJ and scattered in there somewhere are hiking trails and bicycling trails.

I will leave my ramblings there, but will update you guys on what I find in the ultra compact generator category. I am guessing there has got to be something out there that is a little more tiny compared to similar wattage reg gen.

edit - OK all that I found is that the Honda quiet series like the EU1000i is a little smaller in the width, and is lighter in weight, about 15-20 lbs lighter for comparable watts 17.7"L x 9.4"W x 15"H. The Honda's are quite a bit more expensive, brand new they are $1000usd or $1250cdn, used they are about $500cdn. Where as any other used gen can range from $75-$150 for a little more watts and a standard size of around 17"L x 12"W x 15"H @ 50lbs.

I like the aspect of quiet, but that can be achieved as mentioned above, using an enclosure with high flow fans.
An extra 20 lbs, when you got a bunch of other stuff loaded up for long distance travel I think is negligible, especially given the fact you can turn on the gen and just juice up the battery pack in 30 minutes. I will play around with the Motor Simulator a bit to see what an extra 50lbs of generator uses. I just did it, punching in 80Ah, at 41V and a 50lb difference relates to 4km off 176km. For me who hardly pedals I think it will be a neat trip.

I got a little quiet Honda generator. Even though it was the quietest when I was searching for generators it makes NOISE. If you are like me and don't like noise? Get a big inverter and connect it to your car/truck battery. Got to leave the car/truck idling and yes I realize this is a great waste of gas but car/truck engines can be pretty quiet. Also how long will a car/truck idle on a tank of gas? Hours per gallon? Guessing it will idle for a week or so?

I got Xantrex Prosine 1800 Watt inverter. Connect to car/truck battery with 00 gauge wire. Have used this when the power has gone out. Runs the refrigerator, computer, TV, microwave, some lights, and the coffee pot. Coffee pot is the big user of electricity.

Doesn't it make sense to integrate your starter battery, house battery, alternator and solar panel? Every time you are on the road your house battery would be charging, as well as your starter battery, off the same alternator in your car...

See this...

https://www.amazon.ca/CTEK-56-677-Battery-Charger/dp/B005LBCVL4

The CTEK D250S Dual is a 5-step charger that automatically adjusts the charging voltage and current according to the battery state of charge and temperature – reducing a battery’s charge time. This charger obtains its energy from DC sources such as alternators, solar panels or wind power and optimizes this power to meet the charging requirements of different battery banks. It automatically selects the best connected DC energy source (of 2) for the purpose and switches between these energy sources to achieve high efficiency multi-stage charging.

A sensor on the charger senses the battery temperature and adjusts the required charge by increasing the voltage in cold weather ensuring the battery is fully charged, and dropping the voltage in hot weather to avoid the problems of overcharging.

This charger has the additional benefit of an auxiliary input which can be connected directly to solar panels without the need for a regulator, offering free power from the sun and a built-in Maximum Power Point Tracker (MPPT) that helps the solar cells produce power as efficiently as possible by taking the most efficient source of energy from the solar panels automatically, and then using the power to charge the battery. The MPPT searches for the most effective combination of solar cell voltage and current, which ensures that the solar and alternator function in unison to maximize power output. This charger is perfect for boats with one battery, boats with start & service battery, boats with start & service bank, campervans, caravans, RV’s and trucks.

The D250S battery charger has a 5 year Limited warranty

Yep I think it makes sense to charge from the car if it's not a really demanding duty cycle.
Saving on multiple fronts, noise included. Just get enough storage behind the car in 12v and do whatever you want with an inverter. Supplement the recharge with whatever or solar.

And for coffee, I think french press is better than electric drip or perc anyway. Use wood, gas, or etc for that.

I'd just like to find the best alternative to an electric toaster for my friggin Toast tho heheh

Though I have found it acceptable to carry either an 800w generator, or a 3500w generator to camps, depending on my needs, there is a certain amount of sense in the idea to have a good size house battery as well, if you camp a lot.

It just makes some sense, if it tops up as you drive. Then also carry the small genny. That would make it possible to run a 500w 12v charger to the house battery, as needed. Sure, its a lot of stuff, but more or less the same type of setup you see in every RV. They have a house battery, a generator, and ability to just plug in because that kind of redundancy works.

I see no reason not to have the same type of convenience in a smaller rv, van, or car camp. One thing I have thought about for my van, is using my small trailer to carry bikes, and building a chuck wagon into the trailer. The chuck wagon would hold a full camp kitchen, generator, and possibly even a small AC that could be ducted into the van. Before that though, I'd like to just put a house battery in the van.

As far as the size of the house battery goes, you would not want to discharge it more than half. So to wring out 1000wh, you'd need one that holds 2000 wh. This would be in the 200 amp hour ball park. I'm not sure what size a typical trolling motor battery is, or pair of golf cart batteries, but running the charger while the house battery charges will work. I did something similar at the track to charge lipos. I had RC chargers that did not like the 12v from the generator. so I ran the generator to a 12v dumb car charger, to a 20 ah agm, to the RC chargers. Worked fine that way. Kind of funky, but it worked.

Camping coffee,, French press for the win. Fry toast with butter in a pan.

I just stole my 'house battery' from my van for the forklift since the lipos finally went to shit in that. I was running 4s which started it nicely (tho might have blown the alternator regulator hehehe), but they were sick and one string was constantly down at 2v or less. I brought it back from the dead more than once at .1 or .01 c charge depending on dod but they started self discharging badly. from my original pack I beat the shit out of, learning about batteries and more about DC on here.

Anyway, I totally agree in tandem redundant systems, and when we're talking ice thats providing decent amperage all the time when running, that second battery is where it's at for travel charging independently imo. iirc it's like 100ah to an average 12v lead, but that did seem to charge my 24s 10ah pack fine on one charge (to a reasonable 50% dod). Never lower than 11v resting for lead and charge immediately, imo. I'll steal that battery back for the little inverter, fan, tv, chargers, etc whenever it's time. 100$ of indispensable investment when traveling.



======== on charging in particular, is there any lvc beeper alarms that can be set for full cell voltage up to 4.2v? I stopped dicking around with supplies that are set exactly to my end voltage since I stay around them during charge anyway in case of any problem with batt or charger. But an alarm when a cell hits 4.2v would be super useful so you'd only need to be in earshot. Might have to make something? ?

Cellog 8 beeps at full I think, but not loud enough to hear very well. I'm sure it could be hacked to sound a louder alarm.

Could try the high voltage cycle satiator or whatever its called. I really like mine you can charge anything. I usually charge at 75v 5a but when I put the bike in the back of my truck I set it to 2amps and run it on my trucks inverter and charge while im driving to where im going to ride.

You can set it down to 1amp if you wanted and charge off a solar array with a 12v battery and a 5amp $20 inverter not sure how fast you need it to charge

those huge meanwells look like they are very power hungry!

That generator looks like a 2-stroke? theres nothing worse than having to mix oil/gas and then still have a loud shitty power source...If anything try to get a small 4-stroke generator if you have too.

Those little gennys only cost a hundred so that's their appeal I guess.
And 2 stroke is the simplest Ice. I also have a dual fuel 4kw genny from ebay that's nice (esp on propane), but that kinda power and size is more for a whole RV or small house imo. The 2 stroke is just a nice cheap stowable redundancy to a small camp setup. Primarily the car alternator takes care of the switchable combo of vehicle and house batteries (~3000wh ((since yesterday morning buying 2x marine for it)), and another option is a 15v solar panel to trickle charge the bank hooked direct (no controllers etc).

The reason it makes sense to have a battery bank and charge from that via inverter (imo) is because of all the other random stuff you can run either ac or dc. I also run a 24" led tv, powered antenna, tool battery chargers, a fan, and a notepad dock/hub including keyboard/mouse and 2tb external HD. With the proper inverter It also enables you to run an aircompressor for roofing/framing etc, and the miter or circular saws without dragging along (or listening to) a big genny. This will come in handy when I finally build that treehouse down at the river lol.



On another note, some of my first lipos I put thru the wringer back in '15 finally got retired via crowbar and sledge hammer last night in a few frenzied seconds lol. . . . . . . I traded for an original IZIP Trailz and their final task was providing test power at 36v.

The 600/700w feels real weak even compared to even a 1kw hub to me, but wholly shit one of those things moves pretty good with just a 90lb kid on it. The thing is a perfect starter bike for anyone not too heavy or with huge hills imo. The motor has one hell of whine at 36v though lol.

Cellog 8 beeps at full I think, but not loud enough to hear very well. I'm sure it could be hacked to sound a louder alarm.

Click to expand...

Your reasons don't make sense to me, all the things you want to run can run off an inverter or a generator?

I guess you could use the battery bank for kicks and then charge the battery bank when you are out riding your bike with the generator. That way you don't have to listen to it.

I don't even own a generator, but I am in the middle of trying to buy a house so im sure I will have one soon for rehab purposes.

Even when we lose power in winter storms I typically just use batteries/inverter to power things because I find it fun since im a nerd