Alternator Voltage Boost Modification

[john61ct]

all retail LiFePO4 batteries are somewhat grey-market chinese products

I have no idea why you would think so. Yes from fly by night operators like that, but there are reputable dealers that stand by warranty etc for several of the major prismatic makers.

They just charge accordingly for the fact that you're getting fresh brand new cells, not counterfeits, QA rejects or repackaged used.

And if you get a big enough order together with others, it's worth contacting the makers directly and get them to recommend a drop-ship exporter direct from China.

Only problem there is the shipping costs dealing with warranty returns, usually cheaper to just eat it.

 

[john61ct]

Not to mention all the drop-in vendors - if you want to go that way - with distribution channels in place within the US.

And then the packaged system vendors with proprietary BMS included - if you want to go that way - with the same, system integrator / installers / service centers around the country.

The packs made from little cylindrical cell style cells is IMO a hobbyist thing, and certainly a tiny segment of the market for House bank storage systems.

More like an outgrowth of DIY EV, eBike, scooters and RC toys market segments.

 

[john61ct]

Just a note, the cylindrical cells included in the Ryobi etc power tool batts are excellent quality Panasonic / Samsung etc, guaranteed genuine fresh and not QA rejects.

When Home Depot etc run specials, coupons etc, that is usually a cheaper path, and certainly more reliable, than the grey market you're referring to.

 

[Rando]

I have no idea why you would think so. Yes from fly by night operators like that, but there are reputable dealers that stand by warranty etc for several of the major prismatic makers.

They just charge accordingly for the fact that you're getting fresh brand new cells, not counterfeits, QA rejects or repackaged used.

And if you get a big enough order together with others, it's worth contacting the makers directly and get them to recommend a drop-ship exporter direct from China.

Only problem there is the shipping costs dealing with warranty returns, usually cheaper to just eat it.

I think that because none of the common LiFePO4 prismatic cell manufacturers have an international presence or distribution channels. It is not like you are buying cells from Panasonic or Enersys, who stand by their batteries, you are buying cells from CALB or Winston or some other domestic Chinese Manufacturer that provides no warranty, tech support and limited documentation. The only hope of support/warranty is from the few small time retailers in the US who import and resell the batteries.

I as I pointed out, the batteries I purchased met specifications, so I have no complaints about counterfeit/defective batteries.

 

[Rando]

Not to mention all the drop-in vendors - if you want to go that way - with distribution channels in place within the US.

And then the packaged system vendors with proprietary BMS included - if you want to go that way - with the same, system integrator / installers / service centers around the country.

The packs made from little cylindrical cell style cells is IMO a hobbyist thing, and certainly a tiny segment of the market for House bank storage systems.

More like an outgrowth of DIY EV, eBike, scooters and RC toys market segments.

Just a note, the cylindrical cells included in the Ryobi etc power tool batts are excellent quality Panasonic / Samsung etc, guaranteed genuine fresh and not QA rejects.

When Home Depot etc run specials, coupons etc, that is usually a cheaper path, and certainly more reliable, than the grey market you're referring to.

Just to be clear, most of the 'drop in' vendors are actually using many "little cylindrical cells", including local favorites like Battleborne, SmartBattery, etc (and of Tesla of course), so it is not really accurate to say cylindrical are primarily a "hobbyist thing".

You also seem to be mixing up your battery chemistries again - power tool batteries are generally NOT LiFePO4, but are typically 18650 form factor NMC cells which are relatively inexpensive to buy as loose cells.

 

[luthj]

Cobalt flavored lithium chemistries are a bit more energetic than LFP chemistries. This combined with higher energy densities means they are a greater runaway and fire risk. With manufacturers like tesla using cobalt cells, its obvious they can be implemented safely. Tesla uses NMA flavor I think, which are a bit more stable? Obviously the key is a very good BMS. For fractional C applications, the risks are even lower. A properly designed and installed system using lithium cobalt batteries would not worry me in the slightest.

The cylindrical cells seems to be much cheaper to manufacture. Due to their higher volume, it is likely they will remain cheaper than prismatics for a long while.

My reading does seem to reflect the mentioned state of prismatic vendors in the USA. Not much mainstream support for anything below the corporate level.

What does a DIY LFP pack cost these days? Last I heard they were something like 6 or 7$ per AH at 12V nominal.

 

[john61ct]

Just to be clear, most of the 'drop in' vendors are actually using many "little cylindrical cells", including local favorites like Battleborne, SmartBattery

Exactly. My point was in response to your "all LFP batts are shady grey market" statement.

I don't like drop-ins myself. But taking one, or a scrapped EV pack apart, that's what I am calling a hobbyist science project, and less safe than I would recommend for mobile House bank usage.

You also seem to be mixing up your battery chemistries again - power tool batteries are generally NOT LiFePO4, but are typically 18650 form factor NMC cells which are relatively inexpensive to buy as loose cells.

I specifically mentioned Ryobi, which has 4AH 18-20V LFP packs in their One+ form factor, apparently 5-10AH versions coming.

I would think at least one other tool vendor also uses LFP.

Personally I would never use another LI chemistry for mobile House bank usage, unless in future someone like Tesla releases a packaged low-volt DC version of their powerwall designed for RV and marine use, then great!

 

[Ducky's Dad]

I specifically mentioned Ryobi, which has 4AH 18-20V LFP packs in their One+ form factor, apparently 5-10AH versions coming.

The Ryobi 6ah One+ batteries are already on sale at Home Depot, two-pack for $119. Milwaukee will have 12ah M18s available in Q3.

 

[john61ct]

Cool. Apparently the 9AH ones have been spotted overseas. YouTube will have opening and hacking videos in coming weeks I'm sure.

Note Ryobi's guarantee only applies to packs bought in Home Depot.

Other online sources feature lots of counterfeits, the internal cells may be completely different.

But please note none of this has anything to do with what I would consider reasonable or safe for House banks in a mobile setting.

 

[Rando]

I specifically mentioned Ryobi, which has 4AH 18-20V LFP packs in their One+ form factor, apparently 5-10AH versions coming.

The Ryobi 6ah One+ batteries are already on sale at Home Depot, two-pack for $119. Milwaukee will have 12ah M18s available in Q3.

These are not LiFePO4, these are some flavor of Lithium Cobalt.

 

[Rando]

Exactly. My point was in response to your "all LFP batts are shady grey market" statement.

I don't like drop-ins myself. But taking one, or a scrapped EV pack apart, that's what I am calling a hobbyist science project, and less safe than I would recommend for mobile House bank usage.


I specifically mentioned Ryobi, which has 4AH 18-20V LFP packs in their One+ form factor, apparently 5-10AH versions coming.

I would think at least one other tool vendor also uses LFP.

Personally I would never use another LI chemistry for mobile House bank usage, unless in future someone like Tesla releases a packaged low-volt DC version of their powerwall designed for RV and marine use, then great!

My point about grey market LiFePO4 was about cells available for retail sale.

 

[Rando]

Cobalt flavored lithium chemistries are a bit more energetic than LFP chemistries. This combined with higher energy densities means they are a greater runaway and fire risk. With manufacturers like tesla using cobalt cells, its obvious they can be implemented safely. Tesla uses NMA flavor I think, which are a bit more stable? Obviously the key is a very good BMS. For fractional C applications, the risks are even lower. A properly designed and installed system using lithium cobalt batteries would not worry me in the slightest.

The cylindrical cells seems to be much cheaper to manufacture. Due to their higher volume, it is likely they will remain cheaper than prismatics for a long while.

My reading does seem to reflect the mentioned state of prismatic vendors in the USA. Not much mainstream support for anything below the corporate level.

What does a DIY LFP pack cost these days? Last I heard they were something like 6 or 7$ per AH at 12V nominal.

I would agree with you that Cobalt type batteries are not the right choice for a DIY pack at the moment, but with proper engineering, these could be a good option for a commercial pack in the future.

The prismatic LiFePO4 cells have the huge advantage that pack assembly is relatively easy compared to small cylindrical cells. The drawback for me was that the new prismatic cells (CALB, Winston etc) are still quite expensive ($7-8/ Ah @ 12.8V when you consider freight) given their 'grey market' nature. The surplus Full River 5.5Ah LiFePO4 cells I bought were around $1.50/Ah @12.8V, but it works out to $2/Ah when you include the supporting materials (BMS, balancer, shipping etc). I was more comfortable gambling $2/Ah on some unknown cells than $7/Ah, and so far it has worked out well. Of course none of this takes any labor costs into account!

In the end for $300 I tripled my usable battery capacity while keeping the weight the same compared to my prior AGM - an important consideration in a small camper.

 

[john61ct]

My point about grey market LiFePO4 was about cells available for retail sale.

The 180AH prismatics from say CALB are cells.

 

[john61ct]

prismatic cells (CALB, Winston etc) are still quite expensive ($7-8/ Ah @ 12.8V when you consider freight) given their 'grey market' nature.

Again, I have no idea why you would think these are being sold only in the grey market.

Plus all the other counter examples I gave.

True if you're trying to get stuff cheap, ddgy vendors are there.

But if you exclude those from consideration and willing to pay what it takes to get quality, there are legit suppliers

http://www.evwest.com/catalog/product_info.php?products_id=211

 

[Rando]

The point is these CALB (and the like) cells are not supported by the manufacturer, only the importer. This is not necessarily an issue, but it is also not like your are buying from a manufacturer like Enersys through a distributor like batteries plus where you have a support network and can go exchange a cell if it turns out to have an issue. It is also not like I can call a CALB application engineer to ask a question about charge rates or the like.

To this point - one of the handful CALB retailers happens to be close to me, so I actually looked into buying some prismatic cells from them, but it turns out that even the retailers are actually just drop shippers, so I would have had to pay freight even though the retailer is a few miles away.