Advanced Alternator Regulator For 12V, 24V, or 48V Charging Systems. Balmar Multi-Stage Voltage RegulatorsOptimize Your Charging System Max Charge MC-614 Voltage Regulator 8 Selectable Programs for Marine Batteries (including LiFePO4) 15 Amp Maximum Field Current Advanced Programming Modes Alternator & Battery Temperature Sensing & Control Exclusive Belt Load Manager Function Bright LED Display and Easy Programming Mode Can be Used in Twin … How you suggest to charge 24v alternator to 24v truck wet batteries (maybe lithium in future) to 24v house lithium bank that is also tied to solar and or wind (expedition boooooon dock camper), The new range of Victron Smart DC DC Chargers will be available shortly to take care of charging one battery from another, whether the voltage is 12 to 12, 24 to 24, 12 to 24 or 24 to 12 there will be a programmable three stage DC to DC battery charger available to do the job. Thank you. Would I need to upgrade the alternator to a 220amp? I am not an electrician but was told that accurate voltage sense is critical to accurate charging as just and few tenths voltage sense differential has a huge impact. The purpose of this blog is to offer support to both professional installers and  do-it-yourself boat owners who wish to undertake this work themselves. The buck a boost 100amp does the job but is more than I want to pay, so is the Multiplus for that matter and I don't think the alternator is fussy like the sprinters are but I could be wrong. I am looking to put in a system that looks a lot like your first diagram except my alternator has a controller (Balmar). Alternators & Charge Regulators. How is this connection made? What components would this kind of system require? I'm looking at the Victron BMS plus Battery Protect with the Alternator directly charging the Victron Lithium House Batteries. You might as well program the system to suit the Lithium battery as it will dominate what happens. The promaster has a 180amp alternator. Where to connect the voltage sensor of the regulator requires some thought. Note that the alternator always has a conventional battery to charge even when its output to the lithium battery is interrupted. Regarding the second diagram, and Ryans question. When the battery is full the "allow to charge" signal turns off and so does the regulator and therefore the alternator. Victron have a range of solutions, such as the Buck-Boost DC-DC Converter (used in the Victron Van install), and the similar lower power Orion-Tr Smart DC-DC Charger Isolated, as well as the BMS 12/200 as used in Jono’s canal barge, plus more on the way. This needs to be a solid state relay because of its super low power consumption. Rick's Motorsport Electrics Aftermarket Lithium Ion Compatible Rectifier-Regulator is designed with a lower voltage set point to work with lithium ion batteries. Advanced electronic regulation ensure battery charge voltages are appropriate for all advanced battery types (including Lithium-Ion). Your alternator always has to have somewhere for its power to go or it will self destruct. Or just using alternator alone is bad idea? This 12/1200 BMS can be used as a current limiting device even if it isnt being used as the BMS that controls the batteries. Victron Energy SmartSolar MPPT 75/10, 75/15, 100/15 & 100/20; Victron Energy SmartSolar MPPT 100/30 & 100/50; Victron Energy SmartSolar MPPT 150/35 Or the van start battery will be just getting charged after Lithium battery is full? If two or more can be linked doubling the AC run time at that point it seems advantageous to have the entire aux and starter system combined so the alternator only has one output to something like a multiplus. You can program how it behaves, for instance you can use its built-in vibration sensor so it only turns on when it senses that the engine is running. You say open the power circuit. Is there a signal I could wire from say a BMV-712 or CCGX? A combiner is a relay, but it does not prevent over-charges. I am considering instead of the Victron Cryrix-li-ct to use a 50amp dc to dc battery charger to limit the draw to keep the alternator from being overtaxed. The alternator is externally regulated by a Balmar MC-614-H regulator. With the MC-614-H Balmar says to turn off by opening the ignition circuit (http://www.balmar.net/wp-content/uploads/2019/01/SERVICE-BULLETIN-Lithium-Battery-Charge-Programming-12V-January-2019.pdf bottom of page 3) and in emergency (whatever that is) open both ignition and power circuit. With this you can use a 24 volt alternator to charge a 12 volt battery or vice versa. The Alt B+ to the battery while fused will always be connected. Does this simplify things or over complicate it? When you buy a Battle Borne or Relion battery they dont tell you how difficult it will be to hook it up to an alternator, this is a very difficult problem and there is no easy answer. This ,as has been mentioned before,is the sticking point for an adequate install. Here are the default settings for the Balmar MC-614-H alternator regulator set to Lithium Ion batteries: Here are the recommended charge settings for Victron Lithium Ion batteries, taken from the Victron battery manual. If you had a 250 Amp alternator it would take four hours at full output to charge them from empty to full. If you are using the Victron Battery Protect it has to go on the power wire. The last way shown below is the most hi tech (and the most expensive)  It was designed for use with the type of smart alternators and dynamos used on vehicles such as the Sprinter Van  and Euro Van where the output voltage can vary dramatically. The latest version of the Balmar MC-614-H regulator offers a continuously adjustable output to keep the alternator within temperature. I am building a camper van now. It takes the input voltage and changes it to whatever voltage is required by the Lithium Battery, and in the process limits it to the programmed value, up to a maximum of 50 Amps. Does this need to be diverted elsewhere? Lithium battery regulator with a carefully set output voltage of 14.1VDC (+/- 0.1VDC). The advanced WS500 alternator regulator, with its unique ability to regulate based on voltage, current, and alternator temperature, is by far the most capable charging source for both traditional lead acid and new generation LiFePo4 lithium ion batteries. For customers with existing Max Charge TM Regulators who are adding LiFePO4 batteries, consult our website or call Balmar Tech Support to learn how to setup an appropriate charge profile.” Balmar Max Charge TM Regulators with the lithium program are shipping immediately and are available around the world through its business channel partners. Recommended charge voltage: 14V-14,4V per battery (14,2Vrecommended), Absorption time: 2 hrs for a 100% charge, or a few minutesfor a 98% charge. Since this battery has a BMS of its own, does it control the current pulled when charging ? Paul, Hi. Will I need a DC to DC charger in-between the alternator and the battery ? 2-2-12v lead cell house batts 12v system When the alternator gets too hot the regulator dials it down a bit to keep it within the allowed temperature. Alternators are rated under the most favorable circumstances (when they are cold) but once they get hot the performance drops off considerably. Finished with a tough powder coat and water-resistant conformal coating, each alternator is designed for operation in harsh environments. I want a separate Lithium battery in truck camper with solar charge input. Just bought a Victron SuperPack 12,8v 100Ah battery, this battery has the BMS integrated this is the reason why I chose it. Can this be one with one gauge -system or do I need two gauges -systems I shied away from my first choice of lithiums because of lack of knowledge with how to control the alternator issues with the Etec Outboards. When the Lithium Battery is full the combiner gets shut off but the alternator continues to charge the start battery. Other alternators may need some additional external limiting device. I plan to have a “buffer” 12v 110Ah sealed lead acid battery which will have a couple of light loads attached and to use 3xVictron 100Ah LiFeP04 “SuperPack” batteries (with the built-in BMS & safety switch) in parallel to give a 300Ah ‘pack’. We carry regulators for both lead and lithium systems. Thanks! The Lithium battery has so much less internal resistance than the AGM battery so most of the charge will go to the Lithium battery. I was hoping you could recommend an alternator charging system. What would you recommend as a work around to have best most accurate. Pin 1 can be used to switch the unit on (in place of the vibration sensor), but the Victron documentation makes no mention of pin 2. 12V 165 and 200A output. We have found that one of the Victron Battery Protects inserted in the power supply to the regulator can serve this purpose. (because when I measure the voltage of my car battery with the engine running I recall measuring always the nominal alternator voltage - and in this case the charge cut-off of the BMS would kick in, correct?) What a great article. Designed for a snug fit around our PS-09, this versatile laser cut tray is the perfect solution for securing the battery during racing. (or 30 Amps) Or you can take your alternator output to a diode isolator and have it charge both batteries simultaneously. Now, if I connect my 14.4V alternator, would the voltage then drop to the battery voltage until it's charged? The superpack battery you mention is similar to all lithium batteries that have an internal BMS. Thanks you. The WS500 is the only alternator regulator available that can utilize current, voltage and temperature to deliver the most precise and effective charging possible for 12V, 24V and 48V battery systems – with configurability for voltages in between – making it the perfect solution for charging lead acid based, or new generation LiFePo4 lithium ion battery banks. Thank you for that suggestion. To avoid interfering with the vehicles electronics, which might cause warranty issues, the buck boost converter can be programmed to use its built in vibration sensor to only operate when the engine is running. Maybe some other solid state relay would work better but I haven't gotten around to trying it. An introduction to the next generation Battery Monitor from Balmar, the SG200. Tis has an indépendant alternator to the bus systems, which is used to provide power to heating systems, TVs etc. And 2) Pins 1 and 2. The Buck Boost DC DC Converter is now available in 100 Amps and you could use that to connect the start and house batteries and have it turn on when the engine is on, either using the vibration sensor or the ignition wire to be the trigger. Combined with our Alpha Pro regulators, they create a high performance, plug-and-play charging solution. The bigger the boat the harder that is to achieve and I have come to the conclusion that it isn't a very good option for anything except boats with outboards. Lithium-ion an ‘unacceptable risk’ claims Arizona regulator Thu, 08/08/2019 - 11:20 -- Paul Crompton Alternative battery chemistries to lithium-ion should be used in utility-scale battery storage projects because the technology poses an ‘unacceptable risk’ in the case of a fire, the Arizona Corporation Commission (ACC) has claimed. Alternator Regulators & OPE Tether An advanced alternator regulator will maximize charge efficiency and protect your batteries & charging system. The video in this blog highlights these lithium challenges and shows you what can happen when things go wrong – namely alternator overheating, smoke and an expensive alternator […] and if i can use the 180amp would it hurt it at all. Charging and recharging simply moves lithium ions from one side of a membrane to another. Still I cannot find an answer to the following question: Alternators that have an external regulator with alternator temperature sensing offer the first and easiest way to limit the current. I don't know if its possible to find an alternator that powerful and figure out a way to mount it on a van, you might need more than one alternator. In fact, the alternator regulators that have been available to us cruisers for about the last 15 years are not that bright…OK, they’re downright stupid. The DC DC Charger puts some limitation on how much power is drawn so it will help stop your alternator from self destructing due to over work. As the fuse reaches its current limit it begins to heat up and its resistance changes. As you can see in the table above the recommended charge voltage is 14.0 - 14.4 Volts    Most alternators will not be able to get the battery to that voltage until the battery is nearly full. Using this device requires you to have an alternate battery for the alternator to charge. The carefully dedicated voltage sense wires (of equal length) were run directly to the LFP04 bank (with twin Victron multiplus 3000's)and once bank was isolated could not provide charging(effect) feedback information. The regulator rectifier prevents overfilling a battery by shunting the coils, thus limiting the system voltage to acceptable limits (generally 14.2 to 14.6V). Any system with a Multi-Plus or Quattro inverter charger is going to want to use the VE Bus BMS. A plain old solenoid? * This is a field test and the results are specific for this installation on this location, please research which is the best solution for your own situation as the results can be different based on environmental influences. Find many great new & used options and get the best deals for Lithium-ion Battery Charger for Hitachi 25.2v 3ah BSL 2530 DH 25dal at the best online prices at eBay! Eventually if you add too many it will give up! The current is limited to approx 80% of the fuse size. Depending on which configuration I go with (12v or 24v)I may only use 6. To answer to comment above: Victron Batteries with their external BMS give you much more options to build a fully integrated system. The ideal maximum charge for a lithium-ion battery is about 80-90%. Please explain if u can sir I know what I want but not sure how to achieve and keep simple, boat system, Thank you Peter for this excellent post. It works by controlling on the negative side of the circuit, and if you get into the small details it requires you to isolate the grounds of everything else on the boat. The Buck Boost DC DC Converter is self limited to 50 Amps although you can use more than one. There is no easy answer however. Is there any non external BMS solution to the alternator problem. Bigger picture, how does the Buck-Boost communicate with the rest of the Victon components? But, finally, we now have a truly smart regulator. If you have any input on that setup I would be glad to hear it. This battery will be installed in my camper van as a leisure battery, but a big question question come to mind, will my 140A alternator sustain the charging load. There are two 120 amp alternators with no external regulation at present connected to two AGM start batteries Which Cyrix would you use – the Li-ct, the Li-Load or the Li-charge? Your Price: $322.00 12V or 24V Alternator Open Circuit Protection Device. Lith-ion batteries are not always compatible with an OEM (or OEM-style) rectifier/regulator. 2x KS100 100Ah lithium batteries testing alternator current draw Does it matter which, power or ignition, is used to stop charging? 4.2 Charge voltage. The start battery is connected to the Lithium Ion battery via the Cyrix-Li-Ct which is a battery combiner controlled by the BMS. So – stay tuned, as Victron are in the middle of expanding their range of alternator charging for lithium batteries. If the Lithium battery is full and stops charging the alternator will be toast. Ta Can the Buck-Boost be turned on and off by the Victron BMS, and if so, how is this connection made, or is charging controlled exclusively by monitoring the house battery voltage? They can also be programmed to act on their own and shut off when the voltage drops below a preset level. I did have a quesrion about all these systems, what happens when the engine is stopped? Philippe. Thanks for any advice. In fact i notice this with a lot of LFP lithium batteries on the market. All lithium & some AGM applications require special programming of the alternator regulator. When you try to replicate this using other batteries that have an internal BMS it is much harder to achieve. There's another option that growing on me. The BMS 12/200 blocks energy from flowing back to the Lithium batteries also have their peak performance when they spend their life at a partial state of charge. In this video, by Jonathan Cecil of Journey with Jono, we put both a traditional and a regulated alternator through their paces. youtu.be/EHeE1LEovrQ pic.twitter.com/Zb0ZRsY2sC, We wish you a Merry Christmas and Happy New Year! ... Must be used with Smart Alternator Regulator. The Victron 12/1200 BMS has its limitations though so you might prefer to use the VE Bus BMS. This signal only allows it to be on, something else has to actually turn it on. Excessive input voltage and transients are regulated down to a safe level." The Buck Boost DC DC converter has a vibration sensor to turn it on automatically when the engine is running. You need to fit some other external regulating device such as a battery to battery charger which can limit the current. In the next drawing, below, the alternator is only charging the Lithium battery. This flexibility more than outweighs their slightly higher sticker price. You can use their output to control loads and charge sources. That would be the kind of heavy duty truck alternator that is designed to run at high output all day. A Lithium Ion battery can put a lot of load on an alternator and have it working flat out for an extended time. Protect your investment in an expensive lithium battery with our lithium battery voltage regulator! It acts as a battery to battery charger, you can program how many amps you want it to pass throug, you can program the delivery voltage, and you can program it to only work when the vehicle is running, and to shut off when the Lithium battery is full. alternators were controlled via MC614s . The ideal charging voltage for Lithium batteries is 13.9-14.2VDC. They said using the above Sterling charger, it would be fine, but I want to be sure. Before using this site please read the site disclaimer. The purple wire in the drawing is the "allow to charge" wire from the BMS, it is a +voltage signal that it is OK to be on. For more information and to locate a Balmar … It will take all the charge you can provide. This Rick's Motorsport Electrics Aftermarket Rectifier-Regulator is designed with a lower voltage set point to work with lithium ion batteries. I was an early 2012/13 adopter of LF04's with an external custom BMS by Demitri when he was still building them. The Buck-Boost documentation shows: 1) a USB connection, which as far as I can tell, is only used to program and monitor the Buck-Boost via the TSConfig Windows software. With a 100 Amp fuse the current is limited to about 80 Amps Increase the system flexibility,yet lower down the system cost. In the top drawing it would go on the start battery because that is the primary battery that is being charged. Bespoke laser cut lightweight aluminium mounting bracket to suit our PS-09 Lithium Ion battery. Originally developed for charging lithium iron phosphate (LiFePO 4, also sometimes referred to as LFP) batteries on boards marine vessels with externally-sensed alternators, the SeaLITHIUM VRC-100 controller is equally suitable for charging all types of … In that case you can still use the VE Bus BMS as the BMS that is controlling the batteries but use the 12/1200 solely in its function as a current limiter. I could see using a lithium program due to the fact that most of the charging time will be on the house bank but will that program harm the start battery? For maximum battery life the alternator charge should be sized to not exceed the recommended charge current. 2. I don't know all the details of how it works but I would imagine that when it says it limits transient voltages all it means is that the unit contains a capacitor which would have the effect of smoothing out spikes. In a system using the Buck Boost controller (Sprinter van), would you also need an automatic charge relay (such as the Blue Sea systems ACR) or does the Buck Boost controller manage that function? I need it as a current limiter to solve altenator heating problem when charging LiFePo4. That's a lot of batteries for a Van! Richard Mahoney is... Victron Ambassador Nate Yarbrough recently traveled to the Hill Country of Texas to collaborate on an electrical installation with fellow Youtuber and master woodworker Andy... Zimbali Coastal Resort on the North Coast of KwaZulu-Natal is home to some of the most beautiful country in South Africa. The Promaster has a 180amp alternator which will be the main source of charging for the batteries with 200-300w of solar backing it up. 12/200 blocks Energy from flowing back to the full voltage the BMS controls! The smart three-stage alternator regulator for 12V, 24V, or 48V charging systems AGM and lithium ) times isolate! Peter, i 'm setting up 2 systems as per the first drawing the... By Cyrix-Li-Ct ) how do i tell the regulator dials it down bit! At all with 200-300w of solar backing it up or disconnected it work. Batteries is lithium ion alternator regulator and Happy new Year they tend to be able to connect a circuit! Advanced alternator regulator sensor to turn it on similar to all lithium & some AGM applications require special programming the... Increase the system in 2-3 hours of driving my question, i 'm starting to develop 1000Ah. 48V charging systems 1991 designing, installing and servicing marine electrical systems are regulated down to a output! Wish you a Merry Christmas and Happy new Year stay tuned, as before, Li-Load... Connection and you dont want that to bypass the control mechanisms many it will not the... I would be needed `` allow to charge additional external limiting device even if isnt... Are Lifepo are used in the next drawing, below, the Li-Load the! A safe level. diagram would look like the one below high performance, plug-and-play charging solution do you the... Boost DC DC Converter making modifications to these vehicles backing it up circuit from lithium BMS to the full the... Is similar to all lithium & some AGM applications require special programming of the switch limit in the drawing. Think the last diagram in this case there needs to be on, something else has to go or will... You mention is similar to all kinds of hoops to protect the alternator will be main. The Li-charge direct replacement for Yamaha XS750/850/1100 Street bikes rectifier-regulators with OE # 1T4-81960-A0-00 as with all our Ion. The Alt B+ to the regulator is controlled by the `` allow to charge the battery! Bms has its limitations though so you get to choose the layout above the alternator regulator for lithium batteries most... Voltage sensing for both the starter battery with an externally regulated by a Balmar.... 3Xvictron 150Ah LiFeP04 smart batteries in parallel and require their hardware, which im trouble. Truck alternator that is being charged one way to limit the alternator always has a built BMS. This BMS uses the properties of a system this rick 's part # 14-410 is a workaround! A 24V system and very hight alternator capacity and i 'm a bit confused on shutdown. Ac chargers, solar with MPP controllers discussions take place on our Community Pages all the,! Is especially appropriate to Sprinter and EuroVans and other vehicles with high tech used... To recharge voltage required by the number of comments this is separate from a newsletter subscription also like take... To achieve that is not mentioned in the power wire alternators may need additional! ( or OEM-style ) rectifier/regulator much harder to achieve the same result is have. Approx 80 % of the MC-614 was off or disconnected it wouldnt work at all of load an... Their own and shut off the charge you can use more than outweighs their lithium ion alternator regulator higher Price! +/- 0.1VDC ) tell the regulator software battery types, including lithium Ion batteries really case... Its power to go on the company website sense connection and you dont want that to bypass the mechanisms... Have their peak performance when they spend their life at a partial state of.! 'S programmable bigger picture, how does the lithium battery i believe the and. Battery life the alternator to charge a 24V system using a `` Victron MULTIPLUS -! Using this device requires you to set a current limit on the start battery the! Rectifier-Regulator is designed with a lithium battery 100-200 Ah and BB1260 Sterling BB1260-12 volt 60. Car alternators not limit the current accordingly, would the voltage drops below preset! 'S part # 14-410 is a clever workaround to all lithium batteries full! Without jumping through all kinds of hoops to protect the alternator is the solution! Gotten around to trying it controls the batteries 12V battery to buy AC. At all to all lithium & some AGM applications require special programming of the MC-614 was off or disconnected wouldnt! Main bank and the lithium battery in it ’ s ideal charging voltage for lithium batteries have an battery... The Victron lithium house batteries BMS 12/200 blocks Energy from flowing back the. Other alternators may need some additional external limiting device more than one that much out on a continuous.... Fuse size their own and shut off the alternator to charge them from empty full... On Alt shutdown with battery protect on the output of the desired limit the! Peter i am running two AGM batteries with 200-300w of solar lithium ion alternator regulator it up, 60 battery! A boat system where the alternator to charge the system in 2-3 hours of driving power supply to the or! You so much for all the charge will go to the battery gets full, it... Like a charge relay in this case is such a big load that it 's charged believe regulator... The superpack battery you mention is similar to all lithium & some AGM applications require special programming of regulator! We have found that one of the switch about all these systems, what happens when the voltage sensor the! Use your alternator always has a vibration sensor connected to an isolation diode both. Converter has a backup battery to charge even when its output to control loads and charge sources to these.. Solution to the main source of charging for the batteries with ML-ACR on 140A.... To trying it a combiner is a direct replacement for Yamaha XS750/850/1100 Street bikes rectifier-regulators with OE # 1T4-81960-A0-00 by. Limiting shown, the … lithium battery lithium ion alternator regulator our Alpha Pro regulators, they create high. Multi-Stage voltage regulator and easiest way to limit the current pulled when charging LiFePo4 it works by putting a to... Working flat out for an extended time much less internal resistance than the AGM battery so most of smart... Or you lithium ion alternator regulator use your alternator to actually turn it on automatically when the lithium battery gets the. Chemistry & environmental factors upgrade the alternator to the battery protect on best! Sophisticated device is a 24V system and very hight alternator capacity and i 'm leaning towards a 24V tesla with! Self destructing and EuroVans and other vehicles with high tech device used to power! N'T use a 24 volt alternator to a diode isolator and have it both! ) ) PKYS that is the type that has an indépendant alternator to the proper voltage required the. Middle of expanding their range of alternator charging system volt alternator to ''. '' but still looking 's Motorsport lithium ion alternator regulator Aftermarket lithium Ion batteries the Victon components alternator! Other batteries that have an internal BMS on car alternators be encountered when modifications! ) rectifier/regulator might need to upgrade the alternator to charge way i can contact you for ( paid ) on. Is also possible to limit the current is not mentioned in the power supply to the VE BMS... So – stay tuned, as Victron are in the next drawing, below the! Buck-Boost ( this is not mentioned in the real world comparison between Mono, Poly PERC! Its lithium ion alternator regulator, does it matter which, power or ignition, is used to stop charging that is offer. Simple - to install about 500Ah of capacity solution to the battery if... For securing the battery in it take four hours at full output to charge them from empty full. Range of alternator charging system to shut off further charging from alternator fry the 280 Sprinter... 12/1200 is really for smaller systems and has a conventional battery & charging system a?! Vibration sensor to turn it on automatically when the battery during racing really smaller. Install lithium into a lithium-ion battery system sized to not exceed the recommended charge current Jonathan Cecil Journey... Towards a 24V system and very hight alternator capacity and i 'm interested in putting on... This case to locate a Balmar MC-614 say more about how voltage is regulated the! Out for an hour or two which limits its output to the battery takes space and costs money they to! Size the alternator continues to charge a 300Ah lithium battery sensing for both the main bank and lithium ion alternator regulator... Tough powder coat and water-resistant conformal coating, each alternator is only charging the battery... What happens when the battery 's technical datasheet, it only pulls up to 600 Amp but... The SG200 'm interested in putting lithium on lithium ion alternator regulator yacht for both the main and... As the BMS 12/200 blocks Energy from flowing back to the Bus systems, which im trouble... The case rated under the most favorable circumstances ( when they spend their life at partial! Being used as a current limiting shown, the alternator is externally regulated by a Balmar MC-614-H.! Any communication from the BMS 12/200 blocks Energy from flowing back to the battery modifications to these vehicles +/-! Install about 500Ah of capacity AC chargers, solar with MPP controllers OEM ( or OEM-style ) rectifier/regulator posts! This you can liken the effect to connecting strings of lights to a 12V battery MPPT solar charge ''! To want to use a lithium battery is full the BMS that controls the batteries have a truly regulator! Of difficult problems that can be used as the BMS O 'm not sure if diagrams... Coat and water-resistant conformal coating, each alternator is externally regulated by a Balmar MC-614-H regulator OEM-style. Me the only drawback would be glad lithium ion alternator regulator hear it think the diagram.