You can get a NOCO 4 bank charger that would work . Either a Genius 2x4 (2 amps each x 4 bank= 8amps ) , or a Genius GENPRO 10x4 (10amps each x 4 bank= 40amps ). The 2x4 is pretty cheap (like $199.95) and for a slow charge like a trickle . The 10x4 is more robust and more expensive ($424.95) and more like a fast charger .
You can hook these up to 48volt systems that use 4 - 12v batteries x4 in series , and they work perfect . We use these all the time in the boat industry , also with a lot of Lithium battery conversions. (48v trolling motors, large stereo systems , etc) .
If you loosen the red clamp lever several turns the entire assembly should be loose. The crank with the outer tube should lift out the top or push out the bottom as you crank the wheel tube up inside. There is a metal piece that protects the tube from being damaged by the clamp screw that possibly has been pushed in too far and is blocking the outer tube from passing through. You should be able to pull the top half out and look in the hole. It's a pretty simple assembly...
I have a 2024 400 , and it also has that white Alde wire going directly to the negative terminal of the battery . My 24 also came the Victron bluetooth shunt to monitor SOG parameters . Its weird to me that this white wire would go directly to the battery negative instead of the Victron shunt side. I just installed 4 100AH Renogy smart heated batteries in parallel (400AH) , to replace the single 100AH Battleborn , and was unsure about that single white wire from the Alde. I hooked up that wire directly to the negative side of the battery bank just to be safe. Not sure exactly what its purpose is for Alde , so I left it where it is from the factory . If its to prevent voltage spike's , it makes sense that it should go direct to the battery negative.
We have tons of info on the Glycol Exchange, and the 6 year long process to figure out how to do it. I caution everyone watching YouTube videos about the Alde in European Aldes: they use ethylene glycol antifreeze, which absolutely cannot be used in the US Aldes. The constant comments about the "5 year antifreeze" all seem to come from the European videos. So...good idea of the process in the video, but that is all!
This link takes you to the comment on the "DIY Glycol Exchange File" which explains the simple tools and the process.
This thread is the "Changing out the Alde Fluid" files. The six year process to figure out the Alde, how it really works, and how to change the glycol yourself. Plenty of other owners have done this, and they brought back photos and their own little modifications to the basic idea. Not all the trailers are as easy as others. There is more than one way to make the swap. The link goes to the last page of the thread, and you can skim backwards to find the pictures of other owner's DIY days. Tons of information and education about the Alde, the glycol, etc.
I don't work for BB and receive no compensation for this post. It is just a PSA. If you are in the market for BB batteries, this is the best sale I've seen. Good through April 26th:
Many parts for the Dutchman built T@Bs are available from UK based "caravan" dealers. The T@B and Tabbert brand have long been popular in Europe and parts are widely available. When T@Bs first came to the US many parts were imported for the builds.
Looking at the original manufacturers website (https://www.tabme.de/en/) it appears they are still using this or a similar style of handle. You might want to contact them.