Ryobi 40 volt. Anyone ?

Anyone have any experience with the Ryobi 40 volt batteries?
The internets' hasn't got much real world info on their specs yet ... making me wonder about their usefulness or production.
I have had good luck (so far) using the OP4026 40V pack on the newer 40V Ryobi chainsaw.

Just wondering if anyone has dissected them yet, or has some tech reference for the batteries in the pack, or circuitry?

My hi-capacity pack label says : OP4026 LI-ION 40V--- 93.6WH

Voltage test across the + and - terminals (at full charge shows) about 18.34 volts DC :?
http://www.ryobitools.com/catalog/40v/batteries_chargers/OP4026A

I have no experience with this battery but the terminal seem to be configured the same way the Greenworks 40v 4ah packs are. You cant actually get 40v thru the terminals. Once I opened the pack up I found it was 10s2p 18650 and obviously measures the correct voltage at the cells.

ahhh
that nice propriatery BMS so you can only use it with ryobi products
i've ran into the same problem when i bought the canadian tire 40v greenworks and ended up returning it

that battery on Canadian tire is $149.99 is that really what you paid?

skeetab5780 said:

that battery on Canadian tire is $149.99 is that really what you paid?

Click to expand...

Yes.

http://www.canadiantire.ca/en/pdp/outdoor-living/mowers-tractors/lawn-mowers/lawn-mower-accessories/greenworks-40-v-lithium-ion-lawn-mower-battery-0601758p.html#.UoY8VnBQGT8
Specifically : Model: 29302

I took it back though

Edit:

Yea- Canadian tire didn't have these ryobi's in stock-i believe homedepot/lowes have it
but still they are only 2.3AH which is not enough - that's why i picked the greenworks
the price for these is still expensive compared to other options- i only went for these out of curiousity and because needed something right there and than- but with the BMS in the way - i took it back- it was not worth ripping it apart especially for what i paid

Ya I don't blame you at that price. I own 6 of these packs now for a total of 84v12ah But I paid $60 each for them(which is still a lot)

I'm rebuilding my wheels at the moment so have yet to abuse them

I took apart a 24V Ryobi lithium pack (6S2P as I recall) and the BMS was a TI MSP430 microcontroller with a bunch of op-amps shifting the voltage down to the ADC inputs. I didn't see any balance transistors, but they may just have been using the internal transistors on the microcontroller ports. There were also 2x IRF510 FETs to turn off the pack. I believe all the cells were either Sanyo or Panasonic, so I would assume a similar setup in the 40V version.

So, there's a weird proprietary BMS in that style pack? {I think you guys are correct that the Ryobi is a similar "cousin" to the Greenworks 40 volt packs, but not exactly as the WH rating differs somewhat}
I can see that the actual motor (chainsaw & hedge trimmer versions) has only 2 terminals. ---> (+) and (-).
This is contrary to the 4 terminals on both battery pack and charger ---> (+) (T2) (T1) (-)

HOW does that pack deliver the nominal 40 Volts to the motors? Is there a simply a special BMS that somehow senses a load, and does a series connection? :?
OR
Is there some sort of weird switching in the actual motor/tool?

FeralDog said:

HOW does that pack deliver the nominal 40 Volts to the motors? Is there a simply a special BMS that somehow senses a load, and does a series connection? :?

Click to expand...

dmwahl said:

There were also 2x IRF510 FETs to turn off the pack.

Click to expand...

There was also a thermistor taped to the cells to measure temperature, I didn't see a fuse or measuring shunt, but they may be watching the voltage across the FETs as a crude current measurement method.

I may have discovered something strange.
When I use the cheap Harbor Fright VOM meter I get a good 18.4V DC at the packs (-) and (+) terminals.
THEN
I used a digital LED 15-120V Dc display meter on the exact same (-) (+) terminals and instantly got a 40.8 Volts reading !!!
It stayed 40.8 V when I checked again with the HF VOM , then a few minutes later pack voltage went to 18.4 on the HF VOM.

To answer the question concerning any specials near the motor, I have a model 40210, which I bought off of eBay for $58, he came with the new were small low-profile charger, and what I assume is the latest battery pack OP4026 (130186012). I can safely say that on the inside the motor assembly there seems to be no special circuitry at all. Just to heavy gauge wires connecting to the motor it's out and look inside there doesn't seem to be any electronic components inside the motor that I can see.

In the power handle part (the top part) (not the trimmer head) there is only one adjustable (rheostat(?) which adjusts the speed. There is a very large diode with 10A written on it. I measured several kohms on one direction and infinite ohms in the other directions. This is the only two electronics from the battery connector to the actual motor. This small black rheostat switch was the problem with mine. Wish I had tried my 12V battery briefly attached to the trimmer head attachment. (Positive is the larger heart shaped terminal you see when you remove the head. (Don't waste your time taking the entire case apart. Not sure if the part is available but I believe it should be. Saved some plastic from the landfills if so).

Long story included in case anyone else finds this post as I did. Sharing is caring.

Is the Harbor Freight Volt Meter you are using the Red one that is given away for free with the purchase of any thing in the store ?
I have the Red Plastic Case H.F. voltmeter that says cen-tech on the front. However I prefer to use a different Volt Meter I have.

FeralDog said:

I may have discovered something strange.
When I use the cheap Harbor Fright VOM meter I get a good 18.4V DC at the packs (-) and (+) terminals.
THEN
I used a digital LED 15-120V Dc display meter on the exact same (-) (+) terminals and instantly got a 40.8 Volts reading !!!
It stayed 40.8 V when I checked again with the HF VOM , then a few minutes later pack voltage went to 18.4 on the HF VOM.

Click to expand...

jparziale said:

I have a model 40210 ... there seems to be no special circuitry at all.

Click to expand...

Thanks! I bought a 40210 and the trimmer head sucks. It can't be replaced and rolling your own spool or tiny wire rarely works perfectly. The 15" model has a 'bump feed' head similar to the awesome 'speed feed' heads and it rocks. Uses a thicker line, has two feeds, and the spool can be rewound by hand from a single 20ft line. I'm really happy with it.

Anyways, has anyone had any luck dissecting their 40v battery? Or feeding their trimmer with a 16s lipo?

There's some battery dissection pics in the link that's in this thread:

"Ryobi 40V chainsaw"
https://endless-sphere.com/forums/viewtopic.php?f=35&t=75287

spinningmagnets said:

There's some battery dissection pics in the link that's in this thread:

"Ryobi 40V chainsaw"
https://endless-sphere.com/forums/viewtopic.php?f=35&t=75287

Click to expand...

Thanks! I had glossed over that thinking it was just about the motor. I guess I'll be taking apart my trimmer to see if it too runs without the T1/T2 connectors (like the linked chainsaw thread) this weekend. If so, I'm slapping some Andersons on it.

I have one and I opened up and PCB had gotten wet. I cleaned with IPA and discovered I may be missing a capacitor; may have been too aggressive with toothbrush cleaning.

I bought another bad one and discovered different PCB. It had only 1 power regulator for charging instead of two like the first among other things. It seems maybe the older ones like this have the Samsung batteries instead of LG.

If anyone is interested I will keep you apprised if I progress any further.

Thanks for the information. it's really helpful.