Search results

You did cells, not a battery. That is one of the reasons you are getting a better price. It is entirely possible, I would say even likely, that the cells are just out of balance, not deficient. When you buy cells, you need to have the equipment to handle cells. If you want a plug and play...

In general, a four cell BMS is not rated to disconnect a 24V load. If you are lucky, the output MOSFETs of the BMS will fail open, leaving you with an unusable battery. If you are less lucky, the MOSFETs will fail shorted, leaving you with no protection for your cells. Good thing you stayed...

For my capacity tests, I charged with 30A until 3.65V, no CV stage. Rest for 10 minutes, then discharge at 30A to 2.7V. Results varied between 145.5 and 150.7Ah. I've not done any further capacity tests since installing. In my application, a full cycle from full to empty will basically never...

And anyone not buying things for the first time will know to not trust a spec sheet until you have the product in hand and can verify it.

I bought the HiGee 150 Ah cells from BLS in about the same time frame. I did full capacity tests on each individual cell using a programmable PSU and an electronic load. That is in no way needed, but it did give me a lot of information. Most valuable to you would be that while all the 33 cells...

Your charge cut off voltage should be a function of the charge C rate. If you charge at 1C, a cutoff of 3.65V might be just fine. If charging at 0.15C, like you are, the limit should be lower. The 10A charge on a 200Ah pack would only be 0.05C. Cutoff should be lower still.

The BMV700-series meters from Victron have a serial port that could connect to an RPi.

GWL has been a leading distributor of LiFePO cells in Europe for about a decade. I bought my first set of Winston cells from them about ten years back. I've also bought CALB cells through them. In my experience, stock is fresh, packing is excellent, delivery and service is great. You get what...

There are plenty of reseller providing spacers, I'm not denying that. Fortune being one of them. I have never seen an actual cell manufacturer selling spacers. And as to the electrical isolation of cells. Just poke your multimeter probes through the plastic cover and measure to the terminals...

I've only seen spacers provided by resellers, never by cell manufacturers. But I can not prove a negative. Please show us where you've seen this. If your cells move around enough, relative to each other, to chafe the (very thin) plastic cover, I would say you've failed in securing the cells...

Yes, as you understand, it was meant to be worse than worst case scenario figures for the type of battery we're discussing. Aluminium case cells do not have the case electrically connected to any of the poles. There is no need to electrically isolate the cells from each other. Manufacturers of...

No one is claiming there is no heating of the cells, that would be ridiculous. Lets do some numbers: Assuming a 150Ah cell, 3.2V nominal, ca 480Wh Further assume a really poor cell with an internal resistance of 0.5mOhm Discharge the cell completely in one hour at a constant 1C load...

Är those loads I would not worry about cooling.

What kind of loads are you planning for? Until you reach high C rates, the cells don't heat up significantly.

How could you possibly claim that without testing the cells?

If anyone has a system where they worry about a situation where the system would be sitting without charge for long times, just put the low capacity disconnect of loads a little bit higher. An amp hour is not that much for your loads, but can sustain the average BMS for a very long time.

That would be 280Ah cells for about $70 / Wh. The "hour" part is important, without it the numbers mean something completely different.

Decreased voltage will not lead to a higher current carrying capacity for the BMS. The limiting factor is the heat in the MOSFETs. That heat is from resistive losses in the MOSFETs, independent of voltage. A BMS built for 16S will need to have MOSFETs that can handle a voltage of >60V. A BMS...

The question of a good deal is not only about price. It's about quality of the product, reliability of the seller, location of the good, shipping options, etc, etc.

Absolutely not. And if there were no signs of damage to the packaging I would be skeptical of how the other cells were handled before shipping.

The Wago 773, imaged above, are rated for 24A. Do you normally have 120V circuits rated higher than that? That sounds like the older generations of electricians in Sweden did :) Perhaps early push in contacts were bad? I've replaced plenty of light switches and receptacles from the 90s with...

They send stainless hardware. What is your point?

The resistance of the fastener does not matter. The current is carried by the lug directly to the tab/terminal.

Best conductor is silver. Copper seconds, followed by aluminium. Your lugs are also plated, usually with tin. If you are worried about galvanic corrosion, use an antioxidant compound. The correct solution to not stripping the threads is not overtighten the screws. As said earlier, all...

What I think you Americans call wire nuts have not been used in AC installations in Sweden since the nineties. The Wago 221, and other similar models with opening levers, are not used that often since they are rather expensive. We mostly use the simpler versions where you just push the wire in...

Every battery manufacturer in the world use stainless steel hardware, as do every professional installer. If you think you know better, go ahead with brass.

The reason that gold plated fuses exist is because technically illiterate audiophiles believe that it will make the sound sent over gold plated optical cables will sound better. A fuse that is mounted properly in a hold might get surface corrosion in a harsh marine environment, but not in the...

MC4 is a brand name for a connector made originally by the company Multi Contact, now owned by Stäubli. Those are very high quality connectors. There are compatible connector from other quality manufacturers. Helios H4 from Amphenol comes to mind. There are also heaps of cheap copies from...

There is absolutely no need for brass hardware. Stainless is a much better material for fasteners and a lot cheaper. Current carrying capacity is irrelevant. The fasteners role is to clamp the cable lugs to the terminals, not to carry the current.

The terminals on both the Higee 150Ah (sold by BLS) and the CALB CA60 are M6 thread, very comparable in size. The bus bars I received from BLS are of this type: https://www.aliexpress.com/item/4000351777250.html?spm=a2g0o.cart.0.0.43653c00wxMfCm&mp=1 For the CALBs, they are of this style...

I currently have a 60Ah CALB pack in the boat. Those are installed on a plywood shelf with a frame around the base of the batteries, made of ~45x20mm lumber, to keep them in place. Nylon straps hold the cells down. I'll try to snap a photo next time I'm at the boat. For the new cells, I'll make...

The equivalent internal resistance of a cell can not be measured by an ohm meter. A cell can be modeled as an ideal cell in series with a resistor. The value of that resistor is what we call the internal resistance of the cell. There is however no way of measuring it directly. Characterization...

With a top balancing BMS, you should not be doing a bottom balance of the cells before building the pack. It would just create more work for the BMS, taking longer before the pack is in balance and able to give full capacity. If you want to do balancing before building the pack, do a top balance.

Smaller cells give more options for filling the available, iregular spaces on a boat...

The price has been fixed, in USD, for at least a couple of months. The available discount has fluctuated up and down. Right now it's 0%.