Parallel charging multiple solo batteries - Test results

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If you've been in the model aircraft or DIY Drone hobby for a while, you probably know about LiPo chargers and parallel charging multiple batteries. But if you're only experience is something like Solo or Phantoms, you may not know. So here's a quick primer on LiPo chargers and parallel charging. If you already now what it means, you can skip down to "Solo Complications".

A single output Lipo charger can have multiple batteries of the same voltage (3s, 4s, etc) connected to it in parallel. As long as all the batteries are discharged to somewhat similar level, once you connect them all together on a parallel charging board, the voltage will even out on all of them. To the LiPo charger, it will just look like one huge battery. This lets you use a single charger to recharge multiple batteries at once, saving lots of time and hassle. The alternative is a more expensive multi-output charger, or multiple single output chargers.

The solo charger is a 3.3 amp charger. That could take up to 1.5 hours to recharge a single Solo battery from empty to full. There is also no indication or display on the charger to tell you what it's doing. With a conventional LiPo charger, a Solo battery can be recharged at up to 5 amps, which will take it from empty to full in about 50 minutes. Conventional LiPO chargers also have a display that tells you the voltage, how many MAH it's put back into the battery, and how long it took. This is helpful to keep an eye on the health of your batteries. So, I prefer to use my conventional LiPo charger to recharge the Solo batteries. it is faster and more information is available.

Solo Complications
Solo batteries have a brain. Conventional LiPo batteries do not. A conventional LiPo will take whatever you throw at it until it's fully charged, just like any other normal battery. The Solo battery has all kinds of electronics in it to control the flow of electricity and keep the cells balanced. The thing that makes using a conventional LiPO charger a bit more complex is the battery's ability to turn on and off by itself or by the button.
  • The battery has no output until you turn it on. So a LiPo charger that analyzes the battery first (most of them do) will give you a connection error. You have to turn the battery on, and immediately start the LiPo charger so it sees the battery while it's on. Then it will start charging.

  • The battery will protect itself by turning off if the charging current exceeds 5.2 amps (1C). The LiPo charger will stop and indicate connection break. You will need to restart the charging process. As such, I leave the LiPo charger set to 5.0 amps to be safe. Sadly, there is no recharging faster than that without sawing the battery open.

  • The Solo battery may decide it's done charging before the LiPo charger does. When the solo battery's brain decides the battery is full, it will turn itself off. And again, the LiPo charger will indicate connection break instead of full. It doesn't really matter. The battery will be full either way.

  • The Solo battery and charger do not use "hobby standard" connectors like XT60s. So I cut made my own pigtails using the Solo's style connector on one end and an XT60 on the other. Now I can use any normal LiPo charger on my Solo batteries.
Parallel Charging Multiple Solo Batteries
Once I established I could recharge a single battery as described above, I decided to give parallel charging multiple batteries a shot. My LiPo charger is capable of up to 30 amps, so it could theoretically recharge 6 solo batteries at once (5 amps each x 6 batteries = 30 amps total in parallel). However, the batteries brain makes this complicated once again. I have three batteries, which is what I will use in this example below.
  • If you connect all three batteries and turn them all on, the charger will analyze and begin charging as if it's one big 15,600mah battery (5200 x 3). In parallel, the total current from the charger will be split evenly among all three batteries. So I set the LiPo charger to 15 amps (5x3). This works great for a little while.
  • BUT, as described above, once one of them decides it is full, it will shut it self off. Now you only have two batteries sharing 15 amps. The two batteries start getting 7.5 amps each and both of them turn off due to exceeding 5.2 amps.
  • The whole thing fails with one battery full and the other two not necessarily full. What I ended up with was battery #1 full at 16.8v and the other two only about 90% at 16.35v.
  • What was further frustrating is the brains of the battery wouldn't let me top off the remaining 10% no matter what. So I saved a lot of time but didn't get 3 full batteries out of it.
  • If you try to start charging all three at once, sometimes one of them can't figure out whether it should be charging to discharging. (slow blink = charging, fast blink = discharging)
I finally came to the conclusion that the only way to parallel charge multiple Solo batteries is:
  • LiPo charger set for 5 amps. That way it's impossible for any one battery to over-current and trip off.
  • Connect a single battery first. Start the LiPo charger and wait about 10 seconds. Then connect the rest of your batteries. Otherwise sometimes they get confused as described above.
  • This will recharge empty to full in [one hour x # of batteries]. Three batteries in parallel with the LiPo charger on 5 amps took 3 hours. No errors, all full.
  • This saves you the hassle of swapping single batteries charging one at a time. And it saves the time spent between each individual battery. But it's still hours of charging.
If you want to recharge as many batteries as possible, as fast as possible, you would need to the following:
  • A LiPo charger with multiple independent outputs that can each be set for 4s @ 5 amps. These usually come in 2 or 4 output models. To get one with 4 outputs capable of 5 amps each will be about $100-150.
  • Multiple single output LiPo chargers, each set for 4s 5 amps. I think this is self-explanatory.
  • Either way, your recharge time becomes 1 hour for as many batteries at a time as you want. But it obviously costs more $.
JOmBfSLfPe3hTeKwxACT310xpmy-vWlNYlYqoRX6zqTOknzZSetLfPmp_D2APlKe6tky1DEAMHVtsCuY9R1pOmnlsSHPkOOTlsbGpN-SF5oiC1Y90oZPO7QJXx-N7qNqz3T7KvzogELfkC9KeVfw4mHSjbTHOQcHedYIYObuCVL6CSxOjDNkms28p6w7-Iy5CfSUTX7tDBrI9L6TpWeZoYWMUKjwmkjQjhHnGEFNfKb5-bLJ9r_pXwJDDgLKge8uN4CO_6Tn8tSzGR5Qo40jWGm7qxuur2WEP-Q_Z4_ZGcbdSvRxr-rU6IhUSafjzQeN8YzNLXFdkobE8axMeJ3LQDbdol4MesVAAYlo0R1uJQuio6QINZqjs_7FJHueDuvvIekRpSNde0TA1-Qd2trZ55olYcKVp__v8mEJ6tDCDx_vwtVdNE4ovIbYYVvMZpM0478Mvd3_Tja4XqtQqFuhJLtT6-d0h8AquVDzteFS0W0zG74Hz9Y0yeWb0Mj6QWcg-JM27ICypGuUVzV2rqIJT1xydpCOIOTduhBmR1fWnoQXGTv9QmAiZypEdwAs_h1L4MR1Kw=w689-h918-no
 
Why even use a lipo charger? Just find a powersupply with suitable output. That's what I did when I at one time had the evil little white ghost.
 
If you've been in the model aircraft or DIY Drone hobby for a while, you probably know about LiPo chargers and parallel charging multiple batteries. But if you're only experience is something like Solo or Phantoms, you may not know. So here's a quick primer on LiPo chargers and parallel charging. If you already now what it means, you can skip down to "Solo Complications".

A single output Lipo charger can have multiple batteries of the same voltage (3s, 4s, etc) connected to it in parallel. As long as all the batteries are discharged to somewhat similar level, once you connect them all together on a parallel charging board, the voltage will even out on all of them. To the LiPo charger, it will just look like one huge battery. This lets you use a single charger to recharge multiple batteries at once, saving lots of time and hassle. The alternative is a more expensive multi-output charger, or multiple single output chargers.

The solo charger is a 3.3 amp charger. That could take up to 1.5 hours to recharge a single Solo battery from empty to full. There is also no indication or display on the charger to tell you what it's doing. With a conventional LiPo charger, a Solo battery can be recharged at up to 5 amps, which will take it from empty to full in about 50 minutes. Conventional LiPO chargers also have a display that tells you the voltage, how many MAH it's put back into the battery, and how long it took. This is helpful to keep an eye on the health of your batteries. So, I prefer to use my conventional LiPo charger to recharge the Solo batteries. it is faster and more information is available.

Solo Complications
Solo batteries have a brain. Conventional LiPo batteries do not. A conventional LiPo will take whatever you throw at it until it's fully charged, just like any other normal battery. The Solo battery has all kinds of electronics in it to control the flow of electricity and keep the cells balanced. The thing that makes using a conventional LiPO charger a bit more complex is the battery's ability to turn on and off by itself or by the button.
  • The battery has no output until you turn it on. So a LiPo charger that analyzes the battery first (most of them do) will give you a connection error. You have to turn the battery on, and immediately start the LiPo charger so it sees the battery while it's on. Then it will start charging.

  • The battery will protect itself by turning off if the charging current exceeds 5.2 amps (1C). The LiPo charger will stop and indicate connection break. You will need to restart the charging process. As such, I leave the LiPo charger set to 5.0 amps to be safe. Sadly, there is no recharging faster than that without sawing the battery open.

  • The Solo battery may decide it's done charging before the LiPo charger does. When the solo battery's brain decides the battery is full, it will turn itself off. And again, the LiPo charger will indicate connection break instead of full. It doesn't really matter. The battery will be full either way.

  • The Solo battery and charger do not use "hobby standard" connectors like XT60s. So I cut made my own pigtails using the Solo's style connector on one end and an XT60 on the other. Now I can use any normal LiPo charger on my Solo batteries.
Parallel Charging Multiple Solo Batteries
Once I established I could recharge a single battery as described above, I decided to give parallel charging multiple batteries a shot. My LiPo charger is capable of up to 30 amps, so it could theoretically recharge 6 solo batteries at once (5 amps each x 6 batteries = 30 amps total in parallel). However, the batteries brain makes this complicated once again. I have three batteries, which is what I will use in this example below.
  • If you connect all three batteries and turn them all on, the charger will analyze and begin charging as if it's one big 15,600mah battery (5200 x 3). In parallel, the total current from the charger will be split evenly among all three batteries. So I set the LiPo charger to 15 amps (5x3). This works great for a little while.
  • BUT, as described above, once one of them decides it is full, it will shut it self off. Now you only have two batteries sharing 15 amps. The two batteries start getting 7.5 amps each and both of them turn off due to exceeding 5.2 amps.
  • The whole thing fails with one battery full and the other two not necessarily full. What I ended up with was battery #1 full at 16.8v and the other two only about 90% at 16.35v.
  • What was further frustrating is the brains of the battery wouldn't let me top off the remaining 10% no matter what. So I saved a lot of time but didn't get 3 full batteries out of it.
  • If you try to start charging all three at once, sometimes one of them can't figure out whether it should be charging to discharging. (slow blink = charging, fast blink = discharging)
I finally came to the conclusion that the only way to parallel charge multiple Solo batteries is:
  • LiPo charger set for 5 amps. That way it's impossible for any one battery to over-current and trip off.
  • Connect a single battery first. Start the LiPo charger and wait about 10 seconds. Then connect the rest of your batteries. Otherwise sometimes they get confused as described above.
  • This will recharge empty to full in [one hour x # of batteries]. Three batteries in parallel with the LiPo charger on 5 amps took 3 hours. No errors, all full.
  • This saves you the hassle of swapping single batteries charging one at a time. And it saves the time spent between each individual battery. But it's still hours of charging.
If you want to recharge as many batteries as possible, as fast as possible, you would need to the following:
  • A LiPo charger with multiple independent outputs that can each be set for 4s @ 5 amps. These usually come in 2 or 4 output models. To get one with 4 outputs capable of 5 amps each will be about $100-150.
  • Multiple single output LiPo chargers, each set for 4s 5 amps. I think this is self-explanatory.
  • Either way, your recharge time becomes 1 hour for as many batteries at a time as you want. But it obviously costs more $.
JOmBfSLfPe3hTeKwxACT310xpmy-vWlNYlYqoRX6zqTOknzZSetLfPmp_D2APlKe6tky1DEAMHVtsCuY9R1pOmnlsSHPkOOTlsbGpN-SF5oiC1Y90oZPO7QJXx-N7qNqz3T7KvzogELfkC9KeVfw4mHSjbTHOQcHedYIYObuCVL6CSxOjDNkms28p6w7-Iy5CfSUTX7tDBrI9L6TpWeZoYWMUKjwmkjQjhHnGEFNfKb5-bLJ9r_pXwJDDgLKge8uN4CO_6Tn8tSzGR5Qo40jWGm7qxuur2WEP-Q_Z4_ZGcbdSvRxr-rU6IhUSafjzQeN8YzNLXFdkobE8axMeJ3LQDbdol4MesVAAYlo0R1uJQuio6QINZqjs_7FJHueDuvvIekRpSNde0TA1-Qd2trZ55olYcKVp__v8mEJ6tDCDx_vwtVdNE4ovIbYYVvMZpM0478Mvd3_Tja4XqtQqFuhJLtT6-d0h8AquVDzteFS0W0zG74Hz9Y0yeWb0Mj6QWcg-JM27ICypGuUVzV2rqIJT1xydpCOIOTduhBmR1fWnoQXGTv9QmAiZypEdwAs_h1L4MR1Kw=w689-h918-no
Good stuff! Thanks PP!
 
Why even use a lipo charger? Just find a powersupply with suitable output. That's what I did when I at one time had the evil little white ghost.

  1. I already have all this stuff.
  2. Anyone else who's been in this hobby beyond Solo and Phantoms probably also already has this stuff
  3. If you just plug in a 16.8v power supply, you have no means of controlling the current. If that power supply is capable of supply more than 5 amps, the battery will trip off and stop charging to protect itself. If you have one that is not capable of more than 5 amps, I don't know what it will do.
 
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Great information.

Is there any data on how many recharges a Solo battery will take before it's time to dispose of it?
Solo has has only been out for about a year so I don't think anybody has managed to kill one yet.
 
Probably a lot too. It's rated for recharging at a rate up to 10.4 amps. And it's discharge rating is I think 150 amps or so. The 3DR charger only recharges it at 3.3 amps, and in flight, it only discharges at 18-30 amps. So it is not being worked super hard. I suspect they will last a good long time.
 
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