Charging 5th battery

kermeifw

1 mW
Joined
Jul 14, 2017
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18
please forgive my lack of knowledge, I am working on changing that. I have a used Gio PB710. Adding a 5th battery for speed and distance. I plan on following the following link to add the 5th battery to the scooter: http://www.giobikes.org/forum/viewtopic.php?f=40&t=3919 . I am pretty sure I can build the adapter and I have the 5th battery. My question is about charging the batteries. I would assume that the charger, as it is setup now, will only charge the 4 batteries that are in the base of the schooter and that I will need to get a second charger for the extra battery. I have found this one http://www.canadiantire.ca/en/pdp/battery-tender-junior-0-75a-maintainer-0111940p.html#srp . If that is the case, will I have to disconnect the 5th battery while charging either the set of 4 or the lone one or can I leave everything connected and charge them as is? If you haven't looked at the link for how I plan on connecting them it is important to note that the 5th battery is not in a loop with the other 4 but connects just before the controller, the link explains it better than I can. My big concern is charging the batteries, what will be the best way to do that.
 
No matter how you wire these up, you are putting 5 batteries in series to get the 60V. (ie the 5th battery IS in the series with the other 4).

IMHO, your best and simplest option is to get a 60V SLA charger so you can bulk charge the whole set as you do now. There are lots of these available at ebike shops or online. Here's an example:
https://www.aliexpress.com/item/60V...24-4020-b982-43823ae6e81e&transAbTest=ae803_2

Trying to use your 48V charger to charge 4 of the packs and then a separate 12V charger for the 5th battery is very messy, and BTW that 12V trickle charger from CTC is rated at 750 ma or .75 amps. This means to fully charge a depleted 20ah battery could take 25 hrs plus.
 
see this is why one asks questions, I assumed because the 5th battery wasn't connected directly to the other 4 batteries that the charger wouldn't reach the 5th battery, but I apparently was wrong. I definitely will look at upgrading my charger. The reason I was looking at that CTC charger for the single battery was it was what was suggested on another site for charging a single battery. If I was to charge a single battery (12V 12A battery), what does everyone suggest to do that, from what I've read, a typical car battery charger isn't safe to use.
 
Definitely, if you have to buy another 12v sla charger, just buy a 60v sla charger, and then just use that.

If you have a 12v charger around, you can charge the 5th battery still connected. But to do it, it will have to happen when the 48v charger is not in use. The 48v charger would charge just the 4 batteries, connecting to just those 4. Then after, the 5th battery only is connected to the 12v charger. Connections are made at the appropriate terminal to charge just 4, or just 1 battery.

Will your controller blow up on 60v? It will be getting nearly 70v when you start out. 48v controllers usually have 63v max voltage limit.
 
I have read a lot of forums about adding the 5th battery and everyone seems to say it works ok with the Gio PB710 and it's controller, haven't seen anyone yet say it fried their controller. If anyone knows if this will or won't work with the Gio PB710 please let me know. I haven't connected it yet, was planning on doing that today but I might wait just to see what everyone says. I truly appreciate any information, as I said my knowledge in electical scooters is very very little so I will accept all the help I can get.

The only concern I ever saw about the Gio PB710 was that 60v might blow the lights, horn etc. That's why the battery is wired directly between the battery cells and the controller so it doesn't effect the other electrical components. I am correct on this right?
 
A 60V sla system will charge up to a max voltage of ~67.5V. Most 48V controllers have 63V rated caps, so you'll be over specs on the caps. That may shorten the lifespan of the controller caps. The mosfets are probably rated for at least 68V, so no problem there. I've been running a 100.8V pack on my 100V rated caps and fets for 5 years without a problem. ymmv.
 
so I connected the 5th battery as per that forum post I shared earlier, though I didn't use as strong as wire as he suggested as I didn't have any on hand and didn't get a chance to buy any yet. My daughter took it for a test drive and said she thought it was even slower than before (the pb710 doesn't have a speedometer so she can only go on how it felt, and she couldn't do hills as well as before either). I checked before hand and the batteries were charged. Would using the weaker wire or maybe longer wire than required (there is a lot of extra wire but I didn't shorten it incase I messed up and need to redo it) cause the scooter to be slower? I don't know a lot about batteries and electricity but I assume that the scooter wouldn't work at all if I had it hooked up incorrectly.
 
skinny long wire is BAD,
can get away with SHORT skinny wire sometimes, but not long.
 
"bad" as in damaging to the scooter or "bad" as in that is why her speed went down instead of up?
 
bad as it works as a power limiter-accelerates slow
 
Two comments:
  • Even though you believe you have it hooked up properly, I would check with a multi-meter that 60 plus volts is indeed being delivered to the controller. If you don't own a multi-meter, I would advise any ebiker to get one. They can be had for as little as $10.
  • As the batteries are in series, a smaller gauge wire that cannot carry the needed current anywhere in the path will limit the amps to the controller. Not only that, it may heat up trying to do so and in extreme cases, cause something to melt.
 
two steps forward and one step backwards. I need more help. I got 12 gauge wire (couldn't find 10 but from what I can see, the scooter uses 12 anyway). rewired the splitter harness. Charged the batteries. Gave it a try. After a few minutes of me testing it I got my daughter to try. she went about 50 feet, heard a beep and then it died completely. I assume we blew a fuse somewhere. I am going to see what I can find but if anyone knows exactly which fuse I blew and where it is, please let me know. To have full discloser, I also installed a new controller, 12volt 25 amp is what I was told I got that is boosted to give more torque. Any direction here would be a help and I again want to thank everyone for their help so far, saves a lot of time and hunting when people point me in the right direction.

Since I'm making a post, here is a real stupid question, the last person mentioned testing to see what voltage is getting to the controller with a multimeter. I do have one but honestly don't which settings and what I should be seeing for a reading when I test what the batteries are sending to the controller. Any directions here would be much appreciated (I know how to test a single battery with the multimeter but when I do the same with the set of batteries, all it reads is 1.00)
 
update: while hunting around a couple of different forums, I found that the PB710 has a fuse in the battery case, checked and it's blown. Hope that's it. If you think I have other issues please let me know, wouldn't be surprised if it's just not this fuse. I will get one tomorrow after work. Also if people can help me with the multimeter, would appreciate it.
 
kermeifw said:
update: while hunting around a couple of different forums, I found that the PB710 has a fuse in the battery case, checked and it's blown. Hope that's it. If you think I have other issues please let me know, wouldn't be surprised if it's just not this fuse. I will get one tomorrow after work. Also if people can help me with the multimeter, would appreciate it.
If you have 5 12V batteries in series, that means that the +ve from one is attached to the -ve of the 2nd in a string and the +ve of the 2nd is attached to the -ve of the 3rd and so on for all 5. The voltage to the controller will be the +ve from the 1st battery in the series (which is not connected to any other battery) and the -ve from the last battery in the series (which is also not connected to any other battery). The voltage across those two should be 60V plus.

As for the multi-meter, you dial it to the "voltage measurement" section and to a range that includes 60V (probably 0-100V) . Then when the +ve (red) wire on the multi-meter is connected to the +ve on the battery pack and the -ve (black) to the -ve on the battery pack you should see the voltage you are getting.

There are some guides on YouTube about proper use of a multi-meter.

You said something about a 12V Controller in an earlier post? Was that a typo? There is no place for a 12V Controller in this setup. You were running at 48V and are trying to run at 60V
 
yes that was a typo, it is a 48v controller. Thanks for the explaining the multimeter, now I know what I was doing wrong, I was setting the multimeter to 20v as that is what I was shown for one battery, not knowing what the 20 stood for, just told to do that. Knowledge is a wonderful thing. Now that I understand what those settings stand for, I'll test it again tomorrow after I install a new fuse.Wish me luck. I so hope my daughter gets to drive this darn scooter before the summer is over!
 
another update: I put a 30amp fuse in, it was a 25 amp but I found on other forums about fuses blowing after boosting controller and they all suggested getting a 30 amp fuse. It's running again, I took it for a minute drive just to see if it ran and it did. My daughter won't have time until tomorrow evening to do a real test drive, cross your fingers.

I did test with the multimeter and with the 5 batteries it was over 60 volts, can't remember the exact number but I know it was over 60. Hopefully all my issues are behind me.
 
Chances are, under load you sag to below 63v pretty quick. And its not like a 63v cap blows if it sees 64v for a min. It just could. It might blow at 60v too.

Clearly it did not blow. so have fun.
 
Don't play with batteries until you check polarity and voltage. That's chargers and each battery each time you connect. Period. Sla batteries can make fire and can explode. No toys. Check and know. Don't hope or guess.
Remember you can weld steel with that.
You only have as much capacity of your weakest battery. A 10ah a15ah equals 10ah in series.
 
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