Ryobi 18v 4ah, INR18650-20Q

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bluovalguy

100 mW
Joined
Dec 8, 2013
Messages
40
Home Depot recently had a sale buy 1 Ryobi P108 battery ($99) get one free. I already use these tools and have a bunch of chargers, so picked it up hoping they would work on my bike too. Here's what I found.

- TR 10 torx bit required, need to pry a plastic cover off one of the screws, but otherwise easy to take apart.
- 5s2p. Samsung INR18650-20Q cells. (2ah, 15a continuous rating.)
- 20.65v off the charger, 18v nominal. BMS only outputs about 8v until it's hooked to a tool, then the voltage will read properly for awhile till it resets... would be curious to find out how/why it works like this?
- *Added*- 2.1v sag with 18a load when battery is at 50% dod, for 1 battery in use as booster pack.

After finding the pack could handle some decent current, I paralleled these two and ran that in series with a Greenworks battery as a booster pack for about 62v fully charged. (Info on the Greenworks- http://endless-sphere.com/forums/viewtopic.php?f=14&t=55790) I soldered on to the contacts of a P115 battery gauge ($10) and did the same on an old P111 slow charger. The bike runs great at the higher voltage, and the controller is currently at 18a. One problem, it only pulled current out of one battery for some reason. Voltage was off about .1v when I connected them, so maybe the BMS just shut one down? I'm going to try again after recharging and see if that does it. After finding this, I tried both batteries individually at each connector and it ran the bike fine so it's not a wiring issue. I'll report back what ends up happening with this.

Photo_011114_001.jpg

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Keep up the power tool battery posts I recently got a ryobi drill set at home depot and was looking at the 4ah battery they sell and was thinking to myself this thing has booster battery written all over it.....?
 
bluovalguy said:
One problem, it only pulled current out of one battery for some reason. Voltage was off about .1v when I connected them, so maybe the BMS just shut one down? I'm going to try again after recharging and see if that does it. After finding this, I tried both batteries individually at each connector and it ran the bike fine so it's not a wiring issue. I'll report back what ends up happening with this.
Click to expand...

The BMS on these is finnicky... with these charged to the exact same voltage, it still only pulled current out of one of them. After being used in a tool and disconnecting, there is full voltage at the terminals for 1 minute and then it drops to between 5-8v. Since one of my connectors is the battery gauge, it will sync with that fine and continuously provide full voltage... but only for whichever battery was hooked up first. The second one never does a "hand shake" and doesn't activate. Even if you disconnect to sync the second battery and then reconnect the first, they both are active but whichever one was connected last will deactivate after 1 minute. Since these are paralleled at the +/- terminals, it did the same thing whether the batteries were installed on the gauge connector or charger connector, whichever was connected last would not sync.

One interesting thing, the non-sync'd battery will stay active if you keep a load on it. The trick was to activate both batteries and immediately power up the bike. If you stop throttle for 1 minute though, whichever battery was connected last will deactivate. I don't want to mess with that.

My only thought right now is to ditch the charger connector and install a second battery gauge with a disconnect between the two. Sync each battery individually and then connect the two in parallel. Any other ideas? (Hacking the BMS is probably beyond my capabilities, plus I want to keep them usable for the tools.)
 
too bad you couldnt get the greenworks 20v 6ah ones im using 2 in series on a mac kit. it gets me to 25mph and 30mph without wind great batteries
 
jay7264 said:
too bad you couldnt get the greenworks 20v 6ah ones im using 2 in series on a mac kit. it gets me to 25mph and 30mph without wind great batteries
Click to expand...
Where'd you buy them thar batteries?
 
I still have not had any success running two of these in parallel. I bought another ryobi battery gauge for a connector, and wired in a disconnect. When putting those on separately, and then connecting the two in parallel, one battery is still shutting off after 1 minute. I also tried running the series connections first, and only paralleling at the 40v + terminals and the 18v - terminals. Still no luck.

I also tried wiring in an extra load with a flashlight that pulled about .5 amp off of the 18v batteries only. Same problem. It must take a substantial load to keep them from shutting off.

I suppose I could just run 1 at a time, and drop the amps down somewhere in the 10-14 range (planning to do this anyway since 18a is probably pushing the limits of the motor at this higher voltage.)

Anybody have any ideas? I might be open to hacks on the BMS as long as it would still charge on the regular chargers and function normally in the tools. Thanks.
 
Do you think the same cells are used in the new 36v 4ah ryobi tool packs ? INR18650-20Q ?
 
everybody has their own way.
i'd run wires direct to the cells for discharge, and rely on my DVM for volts, to avoid over discharge. after a ride, i'd unplug it and charge normally.
 
There's an old recall on these batteries here:

http://www.ryobitools.com/other_pages/safety_notice/P108_CPSC_Approved_Press_Release_2.26.13.pdf
 
Gab said:
36v 4ah ryobi tool packs ? INR18650-20Q ?
Click to expand...

HAs anyone opened up one of these babies to see what cells inside ?
Click to expand...

Have not seen the "40v" Ryobi batteries to confirm, but Home Depot's MSDS shows INR18650-13q for the high capacity and ICR18650HB2 for the slim. This sounds right, as the 13q in 10s2p would be 2.6ah. I would guess the slim is only 10s1p with 1.5ah. Kind of pricey for either one. You'd be better off with the Greenworks G-Max. About 50% more capacity for slightly less money.


Regarding running two P108's in parallel, I think I have it figured out. The second P150 gauge has different circuitry (it's an older model with a "CA" date code, the newer ones are CW codes.) When the CA is installed, the battery LED's blink. I just realized they do this when on the charger too. Shorting the front battery terminal to + will cause the LEDs to blink and deliver full voltage to +/-. It appears that the CA P150 and the chargers are not fully shorted from front/+ though, there's some resistance in the circuit. I tried shorting a CW P150 from front/+, which worked to keep the battery on even when paralleled, but shut off the P150 LED's. Tried the same on the CA P150 for the heck of it and fried the whole thing.

So I think I will just get two more CA P150's and not mess with them other than tapping into the +/- contacts. I could just solder a wire from front connection to + on the P150's that I have, but since that's not how the old style gauge or chargers work, I would be nervous about damaging the batteries. Any other thoughts?
 
bluovalguy said:
Regarding running two P108's in parallel, I think I have it figured out. The second P150 gauge has different circuitry (it's an older model with a "CA" date code, the newer ones are CW codes.) When the CA is installed, the battery LED's blink. I just realized they do this when on the charger too. Shorting the front battery terminal to + will cause the LEDs to blink and deliver full voltage to +/-. It appears that the CA P150 and the chargers are not fully shorted from front/+ though, there's some resistance in the circuit. I tried shorting a CW P150 from front/+, which worked to keep the battery on even when paralleled, but shut off the P150 LED's. Tried the same on the CA P150 for the heck of it and fried the whole thing.

So I think I will just get two more CA P150's and not mess with them other than tapping into the +/- contacts. I could just solder a wire from front connection to + on the P150's that I have, but since that's not how the old style gauge or chargers work, I would be nervous about damaging the batteries. Any other thoughts?
Click to expand...

For anyone still interested, this works. I picked up two of the CA coded P150's and they will run parallel without any issues now. The battery LED's actually stop blinking after a minute, but both batteries still stay active after that. I don't have a good explanation for this, but at least it works!

One weird thing, when the Ryobi batteries initially go in at full charge, the P150 is somehow stacking on to the voltage after putting a load on it the first time. It reads about .5v higher than when initially plugged in. If the battery it taken out of the P150, it immediately shows normal voltage, but will add .5v again when reinstalling and putting a load on it. At some point (possibly under 20v?) it no longer does this and will just keep initial voltage. Again, can't explain this, but it seems to be functional.

Using these as a booster pack really wakes up the Q100.

View attachment 1
 
Hello,

I used your post as the basis for going ahead and trying my pack ( http://endless-sphere.com/forums/search.php?keywords=p108+ryobi ). I probably would have anyways, but this thread did help out a lot. I was writing to ask three questions

1-could help clarify the whole "sync" thing? Are you talking about how the batteries are only giving out 8.something volts until they got a load or until you press the little green gauge button at the bottom?

2-your problem where it only draws from one battery, did this happen when the 18v was in parallel or in series with the other 18v? I ask because once I get them on, I don't have any issues with the voltage dropping (i.e. it stays at 36v), but I have not yet measured the current coming from each pair of packs to ensure that it is actually drawing from the whole thing.

3-can you please link to the MSDS sheet? I can't seem to find it, even though I know I've seen it before... I am trying to get a confirmation of what kind of cells are in the p108's.

Thanks!
 
BYqSXt8Z said:
Hello,

I used your post as the basis for going ahead and trying my pack ( http://endless-sphere.com/forums/search.php?keywords=p108+ryobi ). I probably would have anyways, but this thread did help out a lot. I was writing to ask three questions

1-could help clarify the whole "sync" thing? Are you talking about how the batteries are only giving out 8.something volts until they got a load or until you press the little green gauge button at the bottom?

2-your problem where it only draws from one battery, did this happen when the 18v was in parallel or in series with the other 18v? I ask because once I get them on, I don't have any issues with the voltage dropping (i.e. it stays at 36v), but I have not yet measured the current coming from each pair of packs to ensure that it is actually drawing from the whole thing.

3-can you please link to the MSDS sheet? I can't seem to find it, even though I know I've seen it before... I am trying to get a confirmation of what kind of cells are in the p108's.

Thanks!
Click to expand...

1- Yeah, I don't know what to call it, but there is some sort of communication that happens between the battery and the gauge that keeps it active beyond 1 minute without a load. Tools don't need this, a load will activate the battery (but only one, if two are in parallel.)

2- The problem was always with running two of these in parallel. They will series fine. If your battery gauges have the code starting "CW", I can almost guarantee that one out of each paralleled set is dropping off after 1 minute. As noted in my last post, the gauges with the "CA" code parallel fine with each other. It seems to do something different with the front terminal, which puts the battery into "on the charger" mode and keeps it active. (As I noted, shorting the front terminal to + makes it blink like that too... don't know if that's a good thing to be doing though.)

3- I never checked the MSDS on these. I took one apart and found the cells are Samsung INR18650-20Q.

I agree with what you said in the other thread about ease of charging and convenience if you already have other Ryobi 18v stuff (I have lots of it.) Good luck with your setup!
 
BYqSXt8Z said:
Mine are CW.

How did you know that one of the parallel batteries was dropping? did the LEDs turn off?
Click to expand...

There was no way to know looking at the gauges, because they were paralleled and both would light up even if only one battery was active. You could tell which one shut off by removing both gauges and immediately measuring battery voltage. The active one would stay at 18v for 1 minute. The "off" battery would be 5-8v.
 
BYqSXt8Z said:
Mine are CW.

How did you know that one of the parallel batteries was dropping? did the LEDs turn off?
Click to expand...

Also... I did find one partial work around. Unplug/replug each battery separately so that both batteries are at 18v. Then keep a load on it. They both seemed to stay on as long as the bike was pulling amps. But as soon as you stop for more than a minute one of the batteries would drop.

Another possible work around with the CW gauges would be to run a resistor (no idea what size) across the front/+ circuits in the gauge to mimic a CA gauge. Do this at your own risk though... don't know if this would damage the the gauge or battery.
 
as far as I can tell, pressing the button in the front (the built-in battery gauge) also "activates" the batteries. I wonder how else I could achieve that... with a switch of some sort or a toggle.
 
BYqSXt8Z said:
as far as I can tell, pressing the button in the front (the built-in battery gauge) also "activates" the batteries. I wonder how else I could achieve that... with a switch of some sort or a toggle.
Click to expand...
Interesting find. Mine does the same. Only problem is if you hold down the button, it still shuts off a few seconds later as if you just pressed/released the button.
 
I ran a test. It is important to note that there was no load on the batteries beyond the fuel gauge.
1-I put my 4 batteries (2s x 2p) in my wire harness
2- let it sit for 5 minutes
3- removed the harness and measured voltage. They were all up there (20v).

Was this the kind of situation where you had a battery going offline?
 
BYqSXt8Z said:
I ran a test. It is important to note that there was no load on the batteries beyond the fuel gauge.
1-I put my 4 batteries (2s x 2p) in my wire harness
2- let it sit for 5 minutes
3- removed the harness and measured voltage. They were all up there (20v).

Was this the kind of situation where you had a battery going offline?
Click to expand...

Run it like that and see if the batteries all drain. Maybe since you're running series as well this is different?

The problem I had was if I pulled the live battery first, the second battery would be activated by the gauge as the first one was removed. So hard to tell unless you happen to pull the idle battery first. One clue though was the gauge LEDs would flicker as the second battery activated.
 
BYqSXt8Z said:
I ran a test. It is important to note that there was no load on the batteries beyond the fuel gauge.
1-I put my 4 batteries (2s x 2p) in my wire harness
2- let it sit for 5 minutes
3- removed the harness and measured voltage. They were all up there (20v).

Was this the kind of situation where you had a battery going offline?
Click to expand...

Try first disconnecting whichever battery was put in the gauge second. If I remember right, that was always the inactive one.
 
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