Secondary alternator gives so much charging potential for a camper van
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- Опубліковано 3 жов 2024
- 140A at idle? 280A while driving? That’s the current this secondary alternator can put out for charging the house battery bank. To do this the system uses a nations starter secondary alternator that is controlled by a Wakespeed WS500 regulator.
![Deep Cycle Battery Charging with your Alternator: The 3 Best Options explained [+ Wiring Diagram]](/img/n.gif)
Hey man I’ve been watching your stuff since you put out the first video of truck camper make half a decade ago. Your electrical videos heavily influenced my AWD ford transit build and utilizing extruded aluminum. From one maker to another you are an amazing guy and sharing your knowledge is exactly the kind of thing I come to UA-cam for. Keep it up 🤙 it’s important.
Thanks so much! Will do and happy travels!
The amount it charges the battery would be proportional to the amount of drag it puts in the system. Might as well have a gas powered generator? I suppose there's some utility in it but it would be pretty niche.
Thats incredible! Does it noticeably affect your MPG?
nice work Sam!
That's insane, I'm already finding my 400W of solar redundant after I installed a renogy DC to DC that only charges at 50 amps. BTW you're building a new van? Your original videos helped me a lot during my own build 2 years ago.
Glad to hear my videos were helpful to you! This was part of some van work I did for a client (and their power needs we’re definitely higher than a lot of use cases). Not currently working a new van for myself (but hoping to renovate our transit next year), but staying busy building vans for clients. More long form UA-cam content to come soon!
@@MoserMakes Does the BMS easily protect against overcharginer, or how do you make sure the alternator isn't trying to put 280 amps into full batteries?
The secondary alternator is controlled by a dedicated regulator - in this case the exact product is a Wakespeed WS500. It monitors the battery voltage, temperature, and current flow from the alternator and adjusts the output of the alternator to only give the batteries what they need and not overcharge them. Beyond that, the batteries internal BMS will make sure they stay within their safe operating parameters.
@@MoserMakes thanks for the quick reply! so theoretically if the batteries weren't asking for anything the alternator would not be running, or it would but not charging the battery and not producing a hazardous amount of heat/current?
basically, outside of cost and "another thing to go wrong", is there any systemic risk or disadvantage? seems kinda like a no brainer if you can afford to invest in it
Yep - that's basically it. If the batteries are charged than the regulator won't have the alternator output any power to the batteries (to be really technical here is an excerpt from an description of how alternator voltage regulators work, "The voltage regulator controls the field current applied to the spinning rotor inside the alternator. When there is no current applied to the field, there is no voltage produced from the alternator").
For a camper van power system system with a battery bank that is larger than can be charged from solar (due to limited roof space) or the limited output of the stock alternator, a secondary alternating is the best option for charging without access to shore power. I don't think there is much downside beyond what you said - the added cost and another part that can go wrong later. It will add some additional load to the engine (another item the engine belts are spinning), but I don't think it's very substantial.
With that said though, most camper vans don't have power systems quite this large and can get away with just charging via solar and smaller dc-dc chargers pulling from the stock alternator. All depends on your power usage and battery bank size.
280 amps 😳⚡️
the question is "will those batteries able to absorb that much power in a fast manner like that?"
That is a great question and something to not overlook during the system design! Different batteries/bms will be able to accept different charge currents and it is also dependent on the total number of batteries in the bank.
What are you using to manage those 280 amps? The biggest DC-DC converter I've seen was in the 100a range. I have 1 250a alternator and 2 Victron Orion 30a DC-DC. Each one is wired to a breaker that's mounted to the base of the driver's seat. If it's cloudy and I'll be driving a long distance I'll just use 1. Shorter distance I'll use both. If I'm getting good solar (720w) I may not use either.
The secondary alternator is managed by a regulator, the Wakespeed WS500. Since the secondary alternator is only for charging the house batteries, the regulator directly controls the alternators output based on the batteries state of charge. The WS500 is pretty smart and uses its own current shunt, voltage and temp sensors for optimal and safe charging.
So it’s a bit of a different type of hardware compared to when you have one alternator which is regulated by the vehicle to charge the starter battery and you use DC-DC charge controllers to charge a house battery as well.
The setup you described is perfect for when you are using the vans primary alternator. I’ve installed quite a few parallel 30A orions like that for clients.
Outside of Victron, Sterling Power released some new 2023 models of their battery to battery chargers with the highest current options being 70A and 120A. On their older models they had a mode you could turn on that limited it to 1/2 power for times you want to lighten the load on the alternator like you described for long drives. From a quick look at the manual though I couldn’t tell if they carried this feature over to the new models, and I haven’t used one hands on yet.
@@MoserMakes Thanks, I'll keep that in mind if I ever do another system.
Can I get info on that alternator?
TIA
you can always just ungrade the stock alternator. no need for a second one