Looking for 6F22 ("9V") 3S (not 2S) LiFePO4 batteries (need 9.6V nominal) - Page 1
Forum section: electronics / general

author: wb0gaz
author_rank: Frequent Contributor
timestamp: June 04, 2021, 08:52:40 pm
content: Looking for source/type/make/manufacturer/brand for 6F22 type LiFePO4 battery that has three cells in series (so nominal voltage is 9.6V.Any types seen recently?Thanks,Dave

author: bdunham7
author_rank: Super Contributor
timestamp: June 04, 2021, 09:01:53 pm
content: https://budgetlightforum.com/node/53245No US availability that I can see. Chargers are available under the SoShine name. If you find any, I'd be interested in knowing how well they work.

author: thm_w
author_rank: Super Contributor
timestamp: June 04, 2021, 09:07:46 pm
content: https://www.aliexpress.com/item/32820366035.htmledit: as below manufacturer verified this is NOT LiFePO4..

author: wb0gaz
author_rank: Frequent Contributor
timestamp: June 05, 2021, 06:43:56 pm
content: Found that soshine actually has their own web site and cites their 6F22 battery -http://www.soshine.com.cn/a57.aspxLooks like it's now (vs. the LiFePO4 mentioned previously) two LiPo cells.Still looking for 3S1P LiFePO4 in 6F22.###New 9V Li-po Rechargeable Battery: 650mAh 7.4VBar Code: 6951151510211Model: Li-7.4V-650SCan charged by other 9V chargerSlim design(15.4mm)Ready to use at any timeSpecification:Type: Rechargeable Li-PoDimension:(48.5+-0.5)*(26.1+-0.2)*(15.4+-0.3)mm (max)C5mAh: 630(mini)C5mA: 650mAhNominal Voltage: 7.4VCapacity : Nominal 650mAhMinimum 630mAhInternal resistance: 144-150 mΩwhen discharged at 0.2C5mA to 5.5VRecommended Charging Conditions:0.2C5mA charge termination control parameters taper current 0.01C5mA at 8.4VService Life: 1,000 cycles(>=60% C5mAh,0.2C discharge)Weight: 28 g (1 cell), 67 (2 cells with package)Charging Voltage: 8.4+/-0.15VAmbient Temperature RangeCharging : 0-45 centigradeDischarging: -20 to +60 centigradeStorage : -20 to +40 centigradeNote:(1) The batteries should be stored at room temperature,charged to about 30% to 50% of capacity.(2) During long term storage,in order to ensure the battery to maintain the capacity level,we suggest Li-ion batteries should be charged and discharged once every 6 months.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: June 25, 2021, 04:56:12 pm
content: That's a normal LiIon battery. For whatever reason, Soshine seems to have abandoned the LiFePO4 6F22 batteries for some years. I bought two a few years ago and now regret I haven't bought more since the two I bought work great for my Fluke 87V and a LEM current clamp. So, I'm trying to buy a few more of these batteries for two years or so. But they have vanished from the stores quite some time ago and while Soshine still sells the chargers for the batteries, there's no other hint on their website that these were ever produced or sold.Like with many other product that were great, these LiFePO4 6F22 batteries are simply gone and nobody seems to care. Everybody seems to be happy with the LiIon batteries even though the voltage is considerably on the low end from the very start.

author: wb0gaz
author_rank: Frequent Contributor
timestamp: June 25, 2021, 06:58:25 pm
content: That's what I encountered --- I imagine there's not enough market capacity for something like this given the prevalence of 7.4V nominal batteries. The only other approach I've seen is to use a 3.7V LiPo and a charge+boost module, but this is likely not a good approach due to continuous drain from the circuitry when not in use.

author: edavid
author_rank: Super Contributor
timestamp: June 25, 2021, 10:22:45 pm
content: Sorry to be that person, but what's the application for the 3S battery? I have not yet found a product where a 2S Li-ion does not work well. Obviously 2S is going to have lower cost and higher energy density than 3S.

author: wb0gaz
author_rank: Frequent Contributor
timestamp: June 26, 2021, 02:43:20 am
content: No problem at all - thanks for asking!In this case, the equipment is a small radio transmitter/receiver that needs ~9V nominal for normal operation; there is an internal non-LDO regulator (which powers an internal RF oscillator) that drops out (too) early in discharge cycle when powered by a 2S LiIon. A 3S LiFePO4 would provide enough voltage over more of it's discharge cycle, which is important for this specific device. A 3S LiPo would not work because at full charge the ~12.6V exceeds limits for some components; a 3S LiFePO4 at full charge would be ~10.8V which is within limit for those components.Dave

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: June 28, 2021, 11:45:58 pm
content: Just for the record: while LiFePO4 9.6V 6F22 batteries seem to have vanished completely, there are a very few NiMH 6F22 "high voltage" batteries with 8 cells, which also have a nominal voltage of 9.6V.Soshine 260mAhTensai 250mAhPowerex 230mAhEmmerich 200mAhGP 170mAhThe Soshine 260mAH battery is totally unavailable at normal stores, the Tensai is sold out everywhere, but the other three are still obtainable. For the moment I decided to try my luck with Powerex before they are also not available anymore.

author: tobyinlu
author_rank: Newbie
timestamp: August 31, 2022, 06:19:54 pm
content: I hope someone is still following this thread.My approach is to use 3 AAA LiFePO4's and to design an adapter.If my measurements are correct they should fit into a standard 9V enclosure.The advantage would be to be able to charge the three batteries separately.What is the maximum voltage of a traditional 9v bloc?Most vendors offer only a graph... using my magnifier I can estimate something like 10V.What can I expect that most appliances will tolerate?The just arrived LiFePO4 have 3.25V => 9.75V.I expect the voltage to be higher immediately after charging.Do I have to discharge the cells to be on the safe side?Any suggestions welcomeTobias

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 31, 2022, 08:12:26 pm
content: Looky here:https://www.ebay.com/itm/253372126102?chn=ps&var=555428525886&_trkparms=ispr%3D1&amdata=enc%3A18S4WF-rSQr6igsaRIZQnOw58&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=555428525886_253372126102&targetid=&device=c&mktype=pla&googleloc=9005066&poi=&campaignid=17597089569&mkgroupid=&rlsatarget=&abcId=9300988&merchantid=101688389&gclid=Cj0KCQjwjbyYBhCdARIsAArC6LJEWEquyA3eQVMrvkMvUgFMtSTAhLWQ0gj92585qhZ6lsxsirMOH9IaAv1HEALw_wcB

author: tunk
author_rank: Super Contributor
timestamp: August 31, 2022, 08:45:54 pm
content: Quote from: BILLPOD on August 31, 2022, 08:12:26 pmThat's a 2S li-ion, not a 3S LiFePO4.

author: tunk
author_rank: Super Contributor
timestamp: August 31, 2022, 08:47:11 pm
content: Quote from: tobyinlu on August 31, 2022, 06:19:54 pmA new 9V alkaline is around 9.6V (assuming six cells at 1.6V).A fully charged LiFePO4 is 3.6V, i.e. 10.6V.If this is too high depends on the application.

author: thm_w
author_rank: Super Contributor
timestamp: August 31, 2022, 09:21:03 pm
content: Quote from: tobyinlu on August 31, 2022, 06:19:54 pmAny drawing of the adapter?Quote from: tunk on August 31, 2022, 08:47:11 pm3.3V is 90% state of charge, so you could stop around there if you were worried, should be safe for almost anything.

author: tobyinlu
author_rank: Newbie
timestamp: December 10, 2022, 12:38:57 pm
content: It's been a while... now I have a prototype. The upper part consists of 1 mm PCB, the lower part of 1,5mm PCB milled down to 0,5mm to keep thelength within max 48.5mm.The contacts a of phosphor bronze, the top buttons fit into holes in the PCB.The negative contact might have short with one of top buttons. I added added an insulation ring. I think I should flip one cell for a next version.I tried to upload more images, but a 356kB file is too large.