Steve in Chester Posted July 26, 2022 Share Posted July 26, 2022 Does anybody know if the 2nd generation Alphards have a Battery Management System? I want to connect a CTEK charger to the battery and have always connected straight to the battery posts in the past. The reason I ask is their website has this in the faq section: The CTEK manual says: ”Connect the black clamp to the vehicle chassis remote from the fuel pipe and the battery". In the picture next to this, the black clamp is connected to the battery's negative pole. Which is correct? When you use a CTEK charger, you can use both connections. The charger should be connected according to the vehicle user manual. If there are no other recommendations in the manual, the negative or black connector should be safely connected to the chassis. The connectors on old “non-smart” chargers can spark if the connectors touch each other, which could be dangerous if this happens near the battery. Keeping the connectors apart, and ensuring the positive connection point is as far away from the negative connection point as possible, will help to minimize any risk. If your vehicle has a BMS you cannot connect to the negative battery pole, the connection must be made to the earth or ground point, if you are in any doubt then connect to the nearest earth or ground point. Eyelets can be permanently connected to the battery as the charger is not usually attached to the eyelet cable when the cable is being connected, so there is no risk. The eyelet connections also give you enough time to check the correct attachment points. Also, if the battery is disconnected or removed from the vehicle then both connections can be made directly to the battery terminal. I was planning on using the eyelets to connect directly to the two battery clamps but unsure about this BMS issue. Thanks in advance, Steve. Quote Link to comment Share on other sites More sharing options...
Chris.ac Posted July 26, 2022 Share Posted July 26, 2022 The 2nd gen do have an additional monitoring system attached to the battery terminal. I think this is in the workshop manual, too; I will try and confirm. Quote Link to comment Share on other sites More sharing options...
Chris.ac Posted July 26, 2022 Share Posted July 26, 2022 Link here to a russian mirror of the electronic workshop manual: http://zatonevkredit.ru/repair_manuals/viewdoc/AWI4O_qhU9h2CeTmduUr If you funnel down through the Power Source / Network section, you can see the battery has a current sensor and temperature sensor. Attached circuit diagram, there is a lot of data here, diagnosis, circuit layouts, components, disassembly instructions etc. Quote Link to comment Share on other sites More sharing options...
Steve in Chester Posted July 27, 2022 Author Share Posted July 27, 2022 10 hours ago, Chris.ac said: The 2nd gen do have an additional monitoring system attached to the battery terminal. Thanks for this, I’ll have a look though the link too. So I should connect the negative charger lead onto an earth point on the chassis somewhere convenient. I hope it’s not done any harm charging it onto the battery posts, it seems to be running fine though. Quote Link to comment Share on other sites More sharing options...
Rojie Posted July 27, 2022 Share Posted July 27, 2022 5 hours ago, Steve in Chester said: Thanks for this, I’ll have a look though the link too. So I should connect the negative charger lead onto an earth point on the chassis somewhere convenient. I hope it’s not done any harm charging it onto the battery posts, it seems to be running fine though. I use a CTEK on the main lead calcium battery, no harm done yet; although I do not use the restore setting. I also use it on the leisure battery when using EHU. Quote Link to comment Share on other sites More sharing options...
Steve in Chester Posted July 28, 2022 Author Share Posted July 28, 2022 Thanks Chris for the info. I’ve not come across these before so it’s good to know. I’ve found some more info about these battery current sensors online. Basically it’s best not to directly connect anything to the negative post or clamp on the main / starter battery. If anyone is interested there’s some general info here: https://www.samarins.com/glossary/battery-sensor.html “If a car has a battery current sensor and additional electrical accessories are connected directly to the battery negative terminal, it may cause problems, because the electric current will bypass the battery current sensor and its readings won't be accurate.” and “It is also important where to connect the wire clamps when boosting or charging the battery with a battery sensor.“ Also, there’s test information here if you need to test it: https://share.qclt.com/丰田Toyota RAV4 Repair Manual/2GR-FE Charging/Battery Current Sensor/02500310.pdf Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.