Any of the generic 40v Ryobi batteries decent?

[timream]

Anyone used any generic brand 40v batteries that can vouch for battery life and longevity? Hard to tell because reviews on the ones I have checked have mixed reviews of works well and dies quickly. It's not that I cant afford new batteries I'm just interested in seeing if there are any more economical alternatives and want to experiment. Also might try building a battery with a shell and individual cells if that's something doable.

 

[videobruce]

The problem with any of these no-name Chinese products is you have no idea just who actually manufactured them. Then add, when they were actually manufactured and nothing of testing or any specifics are stated.

Then add (from my experience and others) the amperage rating that is claimed which is not to believe. Just as Chinese wire gauges that are misrepresented usually by a full gauge number (18 is more like 19 gauge for example).

As to Ryobi; I have one of their mowers and edge trimmer that I bought 4 1/2 years ago. I picked up a extra Ryobi 6ah pack off eBay supposedly new. There is a difference between run times between the 4 and the 6AH packs, but not a 50% increase for the 6AH.
There are two different sizes, only the smaller one fits my mower. The newer mower models will work with the taller packs. I weighed all three packs (all the same physical size) and there was very little difference in weight which makes little sense especially going from a 4AH to a 6AH.

Ryobi 40volt battery packs (prices from May of 2020)

4ah....$140....49.8oz....6 1/2 x 3 7/8 x 3"....2/$260

5ah....$160....50.9oz..............."...................2/$280

6ah....$180......53.5oz,,,,,,,,,,,,,,,",,,,,,,,,,,,..... 2/$340

6ahHP....?.......70oz.....7 3/4 x 5 1/4 x 4 1/2"... (larger pack)

7.5ah...$230....78oz.................."

 

[bertsmobile1]

To say it is very dangerous to use different batteries is an understatement
Li batteries need to handled with caution as they have specific maximum charge & discharge rates
Most E-Scooter fires are caused by using aftermarket batteries or chargers
Note the Lutton Air Port fire
A diesel powered SUV caught fire which is not a problem & easily put out
However it set fire to car next door, again not a problem
But the 3rd car was an EV which exploded setting a dozen more cars on fire & of course could not be put out
Some of the other cars were also EV's and the final result was 2 floors of the car park structurally destroyed plus 1200 vehicles
The insurance claim on this one should be very interesting .

 

[Tiger Small Engine]

To say it is very dangerous to use different batteries is an understatement
Li batteries need to handled with caution as they have specific maximum charge & discharge rates
Most E-Scooter fires are caused by using aftermarket batteries or chargers
Note the Lutton Air Port fire
A diesel powered SUV caught fire which is not a problem & easily put out
However it set fire to car next door, again not a problem
But the 3rd car was an EV which exploded setting a dozen more cars on fire & of course could not be put out
Some of the other cars were also EV's and the final result was 2 floors of the car park structurally destroyed plus 1200 vehicles
The insurance claim on this one should be very interesting .

In general I would say cheap Chinese battery packs are not going to last long. I would also say that manufacturers may claim a battery lasts 5 years before needing to replace. In reality it may be closer to 3 . Wait until you see the cost of battery vs the piece of equipment. I love 2-strokes and gas, we will leave it at that for me.

 

[bertsmobile1]

Like a lot of things the service life of a battery, any chemistry, not just Lithium is determined by so many variables it is not funny and impossible to make an accurate prediction
Some one who cuts there grass every 3 or 4 days will get a longer life out of the same battery than the person who mows every 14 days weather the grass needs it or not
The person with a fine grass like couch will get longer life than the person with buffalo or tufted grasses .
This is because the peak current draw in both of these cases will be lower
The person who runs the battery down till it will no longer run the tool then does a single recharge will get a better life than the person who recharges after every use & never discharges below 75% capacity
The person who leaves the tool on the charger all the time will get a lower battery life than the person who only recharges when necessary
Then there is temperatures to consider, both storeage & during use .
Battery tenders are by and large bad for batteries but people insist on buying them & using them
For batteries that are not going to be used for a long time mine are hooked up to a busbar system ( I have at least 30 batteries ) that is on a 7 day timer & they get 1 hour of charge every 7 days
Does it work ? well some batteries are better than 20 years old & still functional
While they have lost capacity they still have enough power to start the equipment
You do not need a 200Ah battery to start a vehicle that has a functioning recharging system .
Modern batteries have a much shorter life than older ones simply because the plates are 75% thinner so they are easily mechanically damaged and the active paste is around 1/2 to 1/3 the thickness of what it used to be .
This is primarily because car makers specify the quality of the battery that gets fitted and car makers like mower makers want the cheapest possible battery that will outlast the warranty period
The battery is my Rolls Royce hire cars are all better than 20 years old and while not as good as new still have more than enough power to start the engine several times .
While not as good as new ones, if you need to crank an engine for better than 20 minutes then something is drastically wrong with your engine.

My simple test for vehicle batteries is to see if they can start the engine whith the head lights on high beam & my foot on the brake .
When they can no longer do that then it is time to replace them

 

[Tiger Small Engine]

Like a lot of things the service life of a battery, any chemistry, not just Lithium is determined by so many variables it is not funny and impossible to make an accurate prediction
Some one who cuts there grass every 3 or 4 days will get a longer life out of the same battery than the person who mows every 14 days weather the grass needs it or not
The person with a fine grass like couch will get longer life than the person with buffalo or tufted grasses .
This is because the peak current draw in both of these cases will be lower
The person who runs the battery down till it will no longer run the tool then does a single recharge will get a better life than the person who recharges after every use & never discharges below 75% capacity
The person who leaves the tool on the charger all the time will get a lower battery life than the person who only recharges when necessary
Then there is temperatures to consider, both storeage & during use .
Battery tenders are by and large bad for batteries but people insist on buying them & using them
For batteries that are not going to be used for a long time mine are hooked up to a busbar system ( I have at least 30 batteries ) that is on a 7 day timer & they get 1 hour of charge every 7 days
Does it work ? well some batteries are better than 20 years old & still functional
While they have lost capacity they still have enough power to start the equipment
You do not need a 200Ah battery to start a vehicle that has a functioning recharging system .
Modern batteries have a much shorter life than older ones simply because the plates are 75% thinner so they are easily mechanically damaged and the active paste is around 1/2 to 1/3 the thickness of what it used to be .
This is primarily because car makers specify the quality of the battery that gets fitted and car makers like mower makers want the cheapest possible battery that will outlast the warranty period
The battery is my Rolls Royce hire cars are all better than 20 years old and while not as good as new still have more than enough power to start the engine several times .
While not as good as new ones, if you need to crank an engine for better than 20 minutes then something is drastically wrong with your engine.

My simple test for vehicle batteries is to see if they can start the engine whith the head lights on high beam & my foot on the brake .
When they can no longer do that then it is time to replace them

It is supposed to be better for battery life to recharge your cell phone from 50%-80%. So why would you say a person who lets battery go all the way down, then charges is the way to go? Apparently doing this about once a month resets battery % readout accuracy.

 

[bertsmobile1]

Your cell phone battery is not the same chemistry or physical build as you mower battery
A cell phone will run down to 0V because the load is very low so you can drain it totally flat.
A mower draws a lot more power as does a drill so will shut down before the battery is dead flat
Except with liquid metal & flow cell batteries all others use an active chemical paste that is applied over a grid of some sort
Electrons flow easily through the electrolyte but in the paste the opposite has to happen
Remember electrons migrate to the anode and protons migrate to the cathode
So that requires protons to shuffle through paste via solid state diffusion which is a slow process
If the battery is never fully run down then the protons in the past loose their ability to move freely through the paste .
IT is called the memory effect.
Some chemistries are worse than others and NiCd were really badly affected by memory effect .
Li batteries also suffer the same problem and then it is further complicated by the complicated charge rates required to prevent the batteries from exploding during recharging.
Some batteries have a charge controller built into the battery while others have it built into the charger
A lot of the explosions are because a non controlled charger is plugged into a non controlled battery which then goes into thermal run away, gas production and finally BANG.

 

[videobruce]

I believe to get the most number of recharges for a Li-on pack is to charge it to 80%, then discharge it to 20%. Of course, that will affect run time noticeably.
The generally accepted charge range when one stores a Li-on pack more than a couple of months is to charge it to 40 or 50%

BatteryUniversity.com is the place to go for almost anything about dry cells.

 

[Tiger Small Engine]

I believe to get the most number of recharges for a Li-on pack is to charge it to 80%, then discharge it to 20%. Of course, that will affect run time noticeably.
The generally accepted charge range when one stores a Li-on pack more than a couple of months is to charge it to 40 or 50%

BatteryUniversity.com is the place to go for almost anything about dry cells.

Just returned from the Equipment Expo in Louisville, Kentucky. There was tons of battery powered equipment there from trimmers to 60” zero turns. I learned some more about batteries while there and asking questions. I believe what “videobruce” said in above post is accurate about these larger (than cell phone) batteries-topping off to 80% and using until 20% life is left is the ideal charge cycle.
They had an autonomous zero turn there for a mere $75,000. You make one cut in pass around the property, and then set the direction of mow, and it mows by itself. Of course you can buy one zero turn, and get three free for this price. I would like to know the break even point for employee labor saved, etc. The representative couldn’t tell me. Anyway, still not a fan of battery equipment and won’t be servicing any of it, but learning is always good.