latecurtis said:
https://batteryhookup.com/products/2-pack-panasonic-48v-power-module-13s-6-4a-299-99wh
Thanks.
LC. out.
Indeed, impressive price. Build quality appears solid. No BMS though, an extra bother.
I was asking you about them because I was thinking they might fit your stated "use case" of daily errands, occasional long trips, and the mandatory ability to haul the batteries upstairs for charging.
They don't seem to do the trick.
These well built packs are take-offs from UPS duty so they have very high discharge current, paid for by low power density (300wh/8lbs = 37.5 Wh/lb which it two to three times less than packs built on modern 3500-5000 mAh cells)
Even for daily trips you'll need at least two of these 8lb packs, so 16 lbs total, giving you 12.8 Ah or 600 Whrs.
This is if they are indeed "tested like new" as the website claims. The duty graph they show must be showing truthful but it is so randomly put together so it's not clear what exactly it shows. They do cay that the packs "may have never been cycled" which I interpret that they were sitting at full charge all the time being UPS batteries. If that's the case, there must be significant plating build up so I don't know about their "like new" claim. Maybe DrkAngel has first-hand data on them.
In any case, for a half-day trip you'll need twice that much, 24 lbs to be precise, which is heavy as far as lithium batteries go. Recharging them on the go is difficult if you have to bring them inside. Finding an outdoor outlet to charge them on the bike is difficult so when you do find it you'd want to charge them FAST which they are not designed for. But your LTOs are. So LTOs actually would work better for your longish half-day trips even with their heft.
Taking LTOs to run daily errands may be OK if you don't mind a cut in your cargo capacity due to batteries weight.
I know you are concerned about Li-ion "firepower" but if you ever considered Li-ion batteries for you then:
- you could use one well built compact/lightweight pack (say, 6lbs/ 15Ah at 48V) for daily errands. Whiel at store, you can have is with you in the shopping cart.
- for half-day trips you could add a second one
- if you have two ebikes you can keep one battery on each bike, and take the battery from the "second" from one bike when you stray far away from the house.
A pack like this may work:
one like this:
https://enerprof.de/en/ebike-batter...ck-battery-48v-15ah-m50-in-roswheel-bag?c=101
Granted, i's made of cells made in China, but assembled in Germany and have German-build BMS. It's €268.91 which is appr. $300 plus you pay $80 for shipping.
You carry can such pack upstairs no problem so you DON'T need to start a long campaign to concert you van into a solar charging station. Besides labor, you'll have to spend as much on solar HW (likely more, having your unique procurement style.)
The only thing you'd need to do it to deal with "smoke." You can conceivable carry such a lightweight pack in the front basket as you prefer. While charging, you may do it in a fireproof box like the one I referred to earlier. Li-ion batteries don't routinely burn up. WELL BUILT batteries are less likely to do that unless they are abused. If it develops a "thermal incident" anyway, the charge box's charcoal filter will help to lessen the effect. The filter will be ruined after that, sure, so if you you plan to more such incidents then you'll have to replace the filter and likely the charge box. Smoke detectors work. You could use an ammo box but the smoke will be unadulterated and you really have to have some tile or cinder blocks under the box.
Going with the style of this thread, here is how I deal with it. I have three li-ion batteries. Two "frog" type ones, 11Ah/36V bought when I just got into ebiking:
https://www.bixpower.com/BAT-BX3691B-p/bat-bx3691b.htm
I chose this company because it primarily deals with power packs for medical devices and such, with ebike batteries being a side business. Each new supplier is a risk, but I think I can trust that one. No issues after three years.
I use one such battery for errands, I can unclip it with one hand and carry it by the handy handle into stores or businesses. It's about 5 pounds. No wires stick out so the most I get is a quick glance.
I like to pedal so I can get 40-45 miles out of one battery charge.
If I do for a full day trip I take two of those, one rides in the panniers. Change over it trivial. For opportunity charging I use two 2.2A chargers that came with the batteries (unfortunately you can't buy just the battery from BIX)
As much as the anyone, I dream big :lol: so I just bought an Enerpower pack myself, that one:
https://enerprof.de/en/ebike-batter...n-enerpower-frame-bag?number=553610350.9&c=98
That battery is planned to be used on a three-day/300 mi trip next summer, until then it'll be my primary battery for day trips. It'll stay mostly on my V4 Yuba Mundo, with the frog jumping off to the tandem or to the third yet to be built bike. I am thinking of either converting my winder fat tire to electric service, not sure yet if it makes practical sense, or a lightweight low power hybrid for trips involving public transportation. Frog batteries don't get the respect they deserve, for plain vanilla daily biking. I do though routinely carry some 100 lb of rocks and boulders on my Yuba powered by the little 11ah/36V/15A continuous/18A max frog. I live in Minnesota so it's mostly flat but even a small hill here is too much for me to handle without the electric assist even without any cargo. Whenever hills are here they are short, a couple of minutes, so the motor is never hot.
And yes, last but not least. You say that you like LFPs for their ability to delved thousands of cycles and thus contend they are better for daily trips/frequent recharges. I would say that for daily trips you could keep a Li-ion above 20% charge no problem, and also not to charge it above 80%. It's short day trips after all. With such use Li-ion can give you 900 to 1200 full cycle equivalents. One of the reasons I carry the spare "frog" battery on shorter pleasure trips is to not to drain one battery too much. That way I can afford to charge both of them only to 80%. I charge one or both to 100% for longer trips occasionally for capacity and also for balancing. But try to drain 20% from a fully charged battery as quick as possible. All that is not that difficult as it sounds (especially with Grin's Satiator help.)
Not sure if you, LC, find this helpful. I think the way I use my bike(s) is very similar to what you have been planning.