Questions about SLA and lithium together ?

[Crash Machine]

I recently lost my 48v 10 Ah battery in a near head on collision with a coal truck. Eventually I would like to build a new lithium pack for my bike. But today the guy in the local battery store offered me 4 barely used Yuasa 12v 22 Ah batteries for 20 dollars apiece. Seems like a good deal to me.
I know I'll need diodes to protect my batteries but where is the best/easiest/cheapest place to get the right diodes? I look at them online and get lost in all the specs. and such.
Is this even a good idea? I can just keep them in my trailer when I want to take longer rides. But I just wonder if some characteristics of SLA's would be detrimental to my overall system? Seems like a cheap and easy fix to an immediate problem.
Oh, and could I charge them in series with the charger Ping sent with the 48v 10 Ah battery? It charges at 2 amps and has a final voltage of 60.5 volts. Seems a little high for SLA's but I could be wrong.
Any advice on this matter would be greatly appreciated.

 

[picasso]

The Yuasa's are what 13 pounds each? I don't think its worth it to luge them around. LEAD is dead.

 

[BLUESTREAK]

IF you must resort back to that poor LEAD ACID get the diodes from MR> PING 100amp for about 8.00 plus shipping.

 

[dogman dan]

Yes I agree, you have to diode the pings because they won't like it if the bms trips and then there is voltage trying to go through the bms backwards. I may have it backwards too, but as I understand it, it's the bms that is the most vulnerable.

Which brings us to, you could just bypass the bms when paralelling the ping with the lead. Then the diodes would not be as mandatory, and then just monitor the voltage with something. But you need to get the lifepo4 pack to be close to the same voltage as the lead before connecting if you skip the diodes for sure. So it might be, ride a few miles with the lithium, then connect when the lithium has lost a few volts and equals the lead.

Sure, toting the lead would suck, but that's too good a price not to snap em up for a back up. For now, it's a no brainer solution to get something cheap for use today.

The ping charger would take em about 4-6 v too high for the battery longevity. So when you use it, try very hard to be around at the end of the charge, so you can take em off at 55v or thereabouts.

 

[Crash Machine]

Once again thanks Dogman and E.S. My biggest problem is the 5304 is killing the 15 Ah battery. Although it handles the load admirably I see way too much voltage sag. I know this can't be good for it. In fact I am waiting for a cell group from Ping right now. But this cell actually showed problems after a 2 week storage period.
I'll most likely build a lithium battery. Something I would like to do for the knowledge factor. Am even considering Lipo. Better C rating less money but more hassle. Not sure how it would work in parallel with the Ping. Seems like it would solve my C rating problem even if I only had 5 AH of Lipo. I'm still gonna snap up the SLA's. I'll use 'em on the bike I'm gonna build using the old Fusin kit.

 

[dogman dan]

Yeah, some seem to run a 5304 on a 20 ah ping ok, but I still consider 30 ah the minimum for a ping to run an x5. Even if you limit amps, the x5 has a way of always being on that limit, and still hammering the discharge rate.

 

[wineboyrider]

Yeah, some seem to run a 5304 on a 20 ah ping ok, but I still consider 30 ah the minimum for a ping to run an x5. Even if you limit amps, the x5 has a way of always being on that limit, and still hammering the discharge rate.

ag
I got a 36v20ah ping (don't have an x5), but agree with Dogman. Don't hammer your ping. I killed 2 albeit smaller pings running my cyclone 35 amp headline controller. Now I run a 9c DD and max amps is 25 amps on my new 36v20ah ping and it's holding up way better than my other ones. I am hoping to get a few thousand miles on it too, like Dogman :wink:


I do want to run lipo and sla in series with the ping though??
I have the diodes, but I don't know if you can series a ping without dismantling the BMS????

 

[neptronix]

Toss it all and get LiPo packs.

You're gonna get weird battery pack balance issues with SLA and lithium running in parallel. IE one battery pack is going to get drained worse than the other. And when they're in parallel, there isn't really a good way to monitor that. You risk killing a pack.. or suddenly having the ping bms decide that it doesn't want to supply power anymore and you're left in SLA sag land.

Go big or go home; you will be far happier with the end results.

 

[wineboyrider]

Got tons of lipo enough for 18s8p! But, I just wanted to volt up and have some fun