Recent content by kwb78

You just treat them as two separate batteries of 4 cells and let the BMS sort each one out. The balance of cells within each battery is important, but the balance between the two batteries doesn't really matter that much. If wired as I showed, they will stay in balance anyway since as soon as...

When you wire two batteries together in parallel, you should take the positive from one battery and the negative from the other. That means the current passes through the both the positive and negative interconnections and should discharge the batteries equally. Like this: If you do it with...

Most radio hams I know pay quite good attention to the quality of their equipment and especially to antenna feeds and connectors. The PL259 dates from pre-WW2 where it was intended for use at HF frequencies or lower, and it's perfectly sufficient for that use. For higher frequencies it's not...

Two things likely - you probably aren’t getting the plug hot enough for the solder to flow, and as mentioned above use flux, which cleans the surfaces and allows good contact. You need quite a powerful iron with a tip large enough to quickly transfer heat. A lower powered one or tip with small...

It’s almost never worth it going against wind and tide along the Wallet if there’s any sort of blow. Because it’s shallow and the tide is fast running, the chop is particularly short and unpleasant and makes it very difficult to make progress even if your boat will go to windward otherwise. It...

There are different wavelengths of infrared light. You can get infrared cameras which see near-infrared in the range 0.75-1.5µm and shortwave infrared in the range 1.4-3µm, and these work more like visible light cameras, from reflected light. They are what your TV IR remote control uses, and...

They use a completely different operating principle to a visible light camera, and the market is tiny in comparison. To get any capable thermal imager at that price point is remarkably cheap in comparison to what they have been historically. The various Chinese models that use the Infiray...

I would expect them to be failing by that point just from age, let alone running high inverter loads as well. I'd say you've done well to get 9 years out of AGMs with 2 years living aboard.

They do mean lithium ion. The vast majority of their products use lithium ion batteries, with the exception of one which uses LiFePo4. It is easier to use voltage to measure state of charge with lithium ion as the charge curve is not as flat as with LiFePo4 which has vary little variation...

It was also a safety issue. People less steady on their feet could end up being knocked over by the motion, which it why they had to modify it. Here's a paper talking about the phenomenon: Walking on a moving surface: energy-optimal walking motions on a shaky bridge and a shaking treadmill can...

A start battery will probably not pull large currents for sustained periods unless it’s really flat though. You might get 10-20A for the first 10 minutes or so, but on a small lead acid battery that will quickly tail off to a much lower value. That’s part of the reason that alternators alone are...

There are pros and cons of both methods. You will get faster charging of the lithium battery by having it charged directly by the alternator, however the alternator needs to be properly regulated both to ensure it does not overheat with the sustained current a LFP battery can pull, and also to...

Yes, but there was a good reason behind it. The phenomenon that caused it to wobble was unknown prior to the opening of that bridge. Resonance was known to happen with certain circumstances on bridges (eg troops being told to break march and walk), but the resonance on the millennium bridge...

I normally refer people to this document: https://ntrs.nasa.gov/api/citations/19900009424/downloads/19900009424.pdf It's the NASA fastener design manual, which covers various techniques for locking fasteners and why they do or do not work.

Different calibrations and different circuit resistances are probably the reason. If you have a decent multimeter (ie one that is likely to be close to calibrated) you can probably get an idea. First measure the battery voltage directly, which should be the real value. If you then measure the...