Charging AC200L from RV Alternator stuck at 225W with 30V

I have installed a victron DC to DC converter on my RV to charge my AC200L. I have it working but I’m only seeing 225W and I was thinking I would see 350-400. I see 29-31v at the XT90 that I’m plugging in to the Ac200 but it never will go above 225W. I was wondering if I’m missing a setting to allow the unit to recognize the correct voltage.

Thank you

So I have tried all charging modes and have it set back to PV and completed all updates with no luck. I have used this same setup with AC200max and it charged at 400w. Does anyone know any reason why it doesn’t work with the 200l?

Thank you

@MACHZ The 29-31V you measured is the open circuit voltage. Generally, when you plug in our machine and start charging, the voltage will drop to a certain extent. When the input voltage is lower than 30V, the input current will be limited to 8A. So what you mentioned above is normal.

I also think that Bluetti_care made the right diagnosis.
What is the model of your Victron DC-DC? On the Orion TR 12/XXX models you can increase the voltage, I imagine you pushed it to the maximum? the idea being that the voltage is significantly higher than 24V (1) so that your AC200L does not limit the intensity to 8A thinking that it is a cigarette lighter port.
(1) On some models some people say that you even have to be above 30V

The strange part for me is this exact setup works on the AC200MAX but not on the 200L ? I wish I had known this before I purchased the 200L. This is a common setup for overlanders using several different brands but the new BLUETTI can’t handle it?

This is the Victron unit I have it set to 30V

You must have an Orion 12/24-10 or -20…
Alas, the specs show that by adjusting the potentiometer, you can max out at 30V… you must be missing just a few volts for your bluetti not to limit you at 8A.
it’s annoying.
The right model for you is the ORION -Tr 12/48-8 (380 W)… which allows you to boost voltage (boost converter) from 12 V to 40V/60V.

If you can return your 12/24 for a 12/48, (by adding money as the 12/48 is a bit more expensive), it would be ideal !

If you can’t return it and have no use for the 12/24 and are even prepared to render it unusable for a last-chance operation: if you’re a handyman or have a handyman friend, try opening the 12/24, look at the voltage adjustment potentiometer: is there a stop blocking the rotation of the potentiometer and preventing you from recovering a few more volts? if so, try somehow to remove the stop to be able to turn your potentiometer a little more…If you succeed, measure the voltage you obtain before connecting it to your bluetti!

Thank you for the information. I’m not an expert at this so bear with me but I’m still not understanding why this works with the AC200MAX and not the 200L. This converter reads about 31v at the XT 90 connector and on the 200 MAX the input voltage was about 30 ish volts. with the 200L the same 31v at the XT90 reads 28.1-.28.3 on the 200L. That seems like a big loss so I’m wondering if the input is not correct. Is there a way to calibrate the input voltage on the 200L to be sure it’s reading correctly?

To answer your question, from what I have read, the subject of the limitation to 8A to respect the standards of cigarette port sockets (12v and 24v) has been the subject of lively debates and insistent requests (same request than you) to Bluetti who never followed up… And I also have solar generators from another brand (oukitel) and there is the same limitation as for the bluetti. To escape this limitation you must be significantly higher than 24v. In your case it seems that 29v to 30v is not enough. I am not sure that Bluetti will agree to lower the threshold (while being higher than 24V but lower for example than 29V), I am not sure either, even if they wanted to, that they could do it with a firmware update. I’ll let Bluetti answer you.
As for seeing why this threshold differs between 2 Bluetti devices, perhaps the models are not the same, the thresholds are lower for the ac200max than for the AC200L… Perhaps also that the components used (passive components) do not have quite the same values ​​which gives measurements threshold comparisons which differ between two generators of the same model. For example I have 2 ac200max, you know that if there is voltage on the solar input it wakes up the ac200max… I noticed that when I applied a voltage coming from an ac-dc power supply (quite low I don’t know how much exactly) I manage to wake up one of my ac200max… But not the other which needs a higher minimum wake-up voltage…

I have a lot of “maybe’s” but this helps to get to the bottom of the question. Perhaps also the person who has an ac200max for whom it worked has a voltage (>12v) input to the dc dc converter slightly higher than yours which helps to have a slightly higher output voltage ? Perhaps the cables that connect your DC DC converter to your Bluetti are longer and with a smaller diameter (this can cause a slight drop in voltage) than the one with the AC200max…

Thank you again for all of the information. The funny part is the AC200MAX was mine and worked fine with this setup. I purchased the 200l as a “upgrade” and sold the max to a friend. Now I wish I just left it alone as in reality it was working fine. I had a friend that wanted one and didn’t want to spend a ton so I sold him mine. I guess I will wait to see if BLUETTI can help or I will have to sell it and look at another brand. I know one brand uses a XT60i to get past the low voltage limitation.

Thanks again for the help

Your case is interesting
I hope bluetti could do something for you.

in fact you are a happy customer of your ac200max
you promote it to your friend who buys your ac200max, and you take the opportunity to buy the upgraded model, the ac200l.

The ac200l must replace your ac200max, and be used in the same conditions, wiring, recharged by the same dc dc converter… in short exactly the same environment as for your ac200max…

and unfortunately it doesn’t work the same, it works in a degraded manner (slower charging because of the 8A limitation for probably barely a volt or two volts missing).

You are disappointed because you were certain of “backward compatibility”… and this is not the case…

I understand and I hope that someone from bluetti, even in private message, can do something for you.

PS thank you for the XT60i for ecoflow… it’s funny the technical solution they found: just put a metal strip in the middle of a standard XT60 socket (and make a proprietary socket only to connect to the solar panels). the central metal strip is detected by the Ecoflow Unit which then unlocks the 8A barrier… It’s quite basic… but it can help resolve certain situations (and they can sell more expensive proprietary cables!). It would be better to develop algorithms that make it possible to recognize that what is plugged in is a 12V/24V battery (cigarette port) or solar panels… Ingineers have done complicated things like mppt, they must be able to develop this type of recognition … to unlock the 8A limit in 12V/24V. And even if manufacturers are not 100% sure of such an automatic recognition mechanism, they can put an additional security mechanism to offload their responsibility to the user : by forcing the user, if he wishes to activate this recognition function (12V battery/solar panel recognition) to enter an unlocking code, in the event of a problem the user must assume responsibility and not the manufacturer

Is there any way to lower this as 30v seems higher than it needs to be? I haven’t tried yet but I’m thinking my solar panels are around 28V in parallel. So I’m guessing I will have to wire them in series now and with AC’s on the roof the panels will be useless at times because of shading tolerance.

I think that between the assembly in // to avoid losing the power of the panels which are not in the shade but with a limitation in your case to 8A ! and the series assembly which allows you to go up to 15A max (but the power will collapse when a panel is in the shade…): it is better to prefer to put them in series, it will be more interesting if around 12 p.m. all your panels are under the light. On the AC200L I don’t know if you still have the possibility to look at the solar power received (W) and the voltage (V) from your panel… if so, monitor these measurements regularly during the day. and divide W by V to get the intensity. If you find 8A… that means that you are restricted to 8A (but on the other hand if it is higher than 8A that means that you are not restricted… perhaps your panels give more than 30V).

Well after talking with a few people at Bluetti I guess I’m out of luck. I had hoped they would allow the voltage restriction to be bypassed like they do with the turbo AC charging mode but I guess not. I get the restriction has to do with car charging but why not allow the user to bypass it, when not charging from a car? I believe there is a hazard of turbo AC charging without the correct cable that they allow access to so why not allow under 30V to charge at a higher rate with user acknowledgment?

Anyway, I had hoped to add more batteries to my system but I’m going to cut my losses as this won’t work for my alt charging or solar config as other brands will allow. Make sure you keep this in mind, especially in an RV setup.

When a voltage is lowered the volume of electricity needs to be increased to achieve the same rate of charge. Volume needs thicker wire and heavier components. A minimum voltage is required to safely carry a certain amount of volume of electricity is a given component or unit and the two units are different. All things equal, higher voltage equates to easier transmission of the electricity.

I bought two DC-DC (boost) converters 12V to 20V -->48V (384W) to power a grid tie inverter which requires 48V (from the DC12V outputs of a bluetti). I haven’t had time to test them yet. But I also have solar panels with a Vmp of 18V, I will do a test by mounting this panels in parallel and connecting them to my DC-DC boost converter to see if I can avoid the 8A limit by a higher voltage. The boost converters are inexpensive (less than $30 for the 384W model and less than $50 on Aliexpress for the 600W model) and seem to me to have good characteristics:
I will come back I don’t know when to give the result in case anyone is interested.

Thank you for the information but I still struggle to understand why Bluetti would allow faster AC charging even though the stock cables don’t support it but they can’t find a workaround to allow a lower voltage to charge at a higher rate when many of the other manufacturers do allow this. One manufacturer uses a different style XT60i to tell the system that it’s not a car charger and they even have a unit specifically designed to charge from an alternator.

I tried a 36V converter and it worked but the amount of heat generated was more than I was comfortable with. Sure I can next figure out a cooling system but with other options that don’t need to jump through so many hoops, it doesn’t make sense. I love Bluetti features and the form factor but I think not allowing higher charging at lower voltage is a mistake. Make it passcoded or force the user to acknowledge the risk but allow users to make the adjustments needed.

“but the amount of heat generated was more than I was comfortable with.” in fact, it is a disadvantage of this solution.

AC voltage is able to produce higher charge rates because its 120 volt is 10 times the voltage of 12 volts. Higher voltages can produce higher output without heavier components and wiring than 12 vilts can. You would need a cable as thick as your thumb at 12 volts to carry the same power that a pencil lead size wire can at 12 volts. Lower voltages simply are not feasible for large power draws

Hmmm, I guess I’m not following you? This same setup worked with a 200MAX so what is so different with the 200L? I don’t understand why you think the cable would need to be larger. The DC converter is 30V max so I should see around 360 ish watts. The Bluetti limits anything coming in DC under 31V to 8 amps limiting it to 225W. My question is why don’t they allow users to remove the 8 amp limitation that is for protecting a car circuit as the other manufacturers do? Admittedly, I’m not an expert on this so I may be missing your point, so my apologies.

My comment about AC power was related to Bluetti allowing turbocharging that surpasses the factory charging cable by requiring the user to buy a cable and acquire a passcode. It would help if they did the same with the DC input.