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**Sebz** · 02-25-2017, 10:36 AM

#2 Testing the battery

Let's measure the battery voltage:

Note: If you are here it’s because you have voltage out of your charger, it doesn’t mean that it’s still fully functioning, there can be many other problems in the charger.

*Remove the battery pack from the bike or cradle for the testing. Use a actual multimeter to test. Not a wattmeter, or bike display, voltmeter, or charger display.

There are many types of batteries on the market but 2 main classes, hard case and soft packs.

Hard Case packs

Hard case batteries comes in many shapes or form (like the Shark, Dolphin, bottle, rear rack) but they all have a common point, they have a proprietary terminal to connect to the cradle (discharge) and a charge port (normally a 5mm female barrel connector)

Testing the discharge port on a hard case:

To test the hard case you need first remove it from the cradle and locate the terminal on the back, some have 2,3,4 or 5 holes, tabs, prongs, clips… they are all the same, 2 of these will give you the voltage.

like the shark for example:

Or the Dolphin (there is a +,- on the terminal)

The multimeter just reads the voltage, you won't short anything unless you cross your multimeter probes and touch the + with the - so you can test the charge and discharge ports even if you do not know which side is negative or positive. So just like testing the charger you want to test both charge and discharge on the battery.
After plugging an xt60-barrel adapter to a barrel port (not plugging into the charger, just the adapter in the battery), the plus side of the xt60 should be going to the red multimeter lead and the minus side should go to black, and you should see positive voltage when testing for voltage, not negative voltage. If you did see negative voltage here the charging port on the pack would be miswired.

The idea here is to individually test each potential point of failure by comparing it to the others.

The charger wiring
The adapter wiring
The battery charge port wiring

You can do the same testing of voltage with the discharge connection so you have something else to compare it to, and to make sure the BMS is not tripped. If it is tripped you will see very little voltage and it will need either a jumpstart or regular charging before the BMS resets.

Note all your testing results, it can come handy when you contact your supplier!

Soft pack batteries

Testing the discharge on the soft pack:

Locate the connector that goes to your motor/controller:

Most of Luna’s soft packs (exceptions being the 72V 100amp pack) come with a XT-90-S connection (it’s the bigger of the 2)

Just put multimeter test probes in the connector and measure the voltage.

Charge port testing on hard cases:

This is the tricky part if you have a barrel port and your charger is only a 30$ (or so) barrel plug unit it’s really difficult to measure the voltage without shorting out the positive and negative , If you have an old 5.5mm barrel plug on a old electronics device you could cut the wires and strip them (make sure you separate them so they won't touch each other and measure the voltage from the wires! Is not still this test.

But if you have the charging adaptor to convert the male barrel to a XT-60 to charge with a Luna advanced (mini or 300W) charger you can do the test. Just plug the adaptor in the port and measure the voltage on the terminals on the XT-60 connector. If you don’t see any voltage, test the continuity of the adaptor, they are a common point of failure.

Charge port testing on the Soft packs:

Just measure the voltage from the XT-60 (the smaller).

Results interpretations charge and discharge port testing:

Discharge port : If you have anything from

0-27V on a 36V batt
0-35V on a 48V batt
0-38V on the 52V batt
0-44v on a 60V batt
0-55V on a 72V

That means the BMS is either tripped or damaged, go to the charge test and if needed go to the jump starting procedure below.

Charge port: if you have a lower voltage (like the discharge port results) continue with the testing the charger, the BMS may be tripped.

If you tested the battery correctly and your results are normal, same as the discharge port (if not tripped BMS) meaning you have between 38V to 58.8 on a 52V pack.it can be a bad charger or a damaged BMS.

2.1 Lets try to charge that battery properly:

Plug the charger in the AC outlet. If you have a Luna mini or advanced , select the 100% position before the AC plug.
Refer to your battery model charging procedure** and plug the charger in the charging port of the battery.
If you have a fan, the fan should start and and the red light will be on (both red in the case of the Luna mini and 300W advanced chargers). This indicates that the charging process is started. if nothing happens or the charger is cycling, ticking before the end move to the jumpstarting. if you have a luna charger and you are using a charging adaptor (barrel to Xt-60), test the continuity of both wires, it can very be the issue.
Once the charger goes green, unplug it and test the voltage (discharge), you should read the full voltage (or close to) of the battery rating. if you don’t you may have a tripped BMS or a defective charger. So move to the jumpstart.

Links on charging procedure:

Beginner guide to charging batteries
Charging a Jumbo / Killer whale pack

“**” Some of the jumbo and killer whale, dolphins needs the on/off switch to be toggled, read here.

2.2 Jumpstarting your BMS externally:

Is the BMS your problem?

The BMS is the protection system that keeps your battery safe (read the article on BMS)
Unfortunately sometimes an overzealous BMS can keep an otherwise good pack from working. More often than not in a failed pack it is a bad BMS.
For example many BMSs have a short circuit protection. If they detect a short they shut down the pack and the BMS can sometimes not be reset so easily.
One typical thing that can happen with a high amperage battery is plugging in the battery or even switching on the wrong kind of on/off switch can trigger a spark which the BMS reads as a short and instantly shuts down.
To avoid this use xt90s spark resistor connectors when plugging in your battery.
If your BMS has shut down the pack, the first thing is to try charging the pack. but if you are here this means it did not work and you need more extreme measures to revive it.

Sometimes to reset a BMS requires charging through the discharge wires for a few seconds to jolt the BMS back to normal mode. After charging for a few seconds from the lead wires try charging now through the normal charge wire and see if the pack charges normally.
If it charges OK, now try it on the bike and make sure it discharges OK.

NOTE: It is important that you do not use the discharge wires to charge your battery for more than a few minutes because you will have no BMS protection if you do so.

You can see our guide on how to do this with a shark pack:

Link to jumpstart

The jumpstart procedure in this article covers the shark packs but it’s pretty much the same for all batteries, you might need to make an adaptor or use some wires to do it. if you built your bike by yourself you probably can figure out how to do this. Just make sure you respect the polarity of the battery (you should know it because you tested it with your multimeter).

If you have a softpack battery check out this video

If you have a barrel type charger please wire it this way:

Note: If your charger is the Grin Satiator, follow this procedure.

RESULTS of the jumpstart:

If the charger started and you have now normal voltage out of it and you can charge normally….well it’s time to ride your bike and test the dischage.

If the jumpstart didnt worked, the charger never started or you can’t charge you pack on either ports, it probably means that the charger need to be replaced first, there is a slight risk that the BMS is acting up too. But changing the charger is the first step, contact your supplier if the charger is still covered under warranty.

If the jumpstart worked and the charger was running till you removed it and still not charging normally it probably means that the BMS is still the issue. There is another reset procedure on some BMS’s but it involves the opening the battery and unplugging the balance connection (sense wires) and plugging it back. So at this point before opening the battery you should talk to your supplier. After you talk to your supplier you can move to the next section below.

2.3 You have voltage but still can't power the bike, let's try to do a load test on the battery.

-Similar to a jumstart but a light bulb instead of the charger. Incadescent light bulbs are perfect... the higher the wattage the better... 100W is fine 300W is better... remember a battery at 52V will only output about 18W if you connect it to a 100W light bulb. Avoid LED and CFL as most of them can't take DC and can't deal with anything lower than 100V.

Watch this video

DISCLAIMER: We use the terms, can, should… because it’s not 100% sure that changing a charger will fix your issue, it’s just means that based on the results the most likely culprit is the charger and we recommend to try to replace it before sending a pack back to your supplier or try to open the pack to test or replace the BMS.

Attached Files

**Sebz** · 02-25-2017, 10:43 AM

STEP #3

Disassembling your Battery, (and your supplier is aware that you are attempting to do this.)

Note that lithium packs contain a large amount of energy and can discharge it in a dangerously short period of time resulting a shock or fire. If you are not completely comfortable working on large battery arrays contact us for further direction.

Disassembling your battery is not as hard as it sounds especially if you have a hard pack such as a shark or dolphin pack.
Just undo the screws and you should be able to have your pack taken apart in a few minutes.

Opening a shark case, click here

If you have a soft shrink wrapped battery you are going to have to cut open the shrink wrap. This is easy to do but re-shrink wrapping your pack is a lot more work and you may want to just settle on duct taping it instead which works just as good but does not look as nice and is not as waterproof.

In dept article on opening a soft pack

What to look for once your pack is disassembled?
.

First thing to look for is physical damage. Do you see burn marks by any of the cells. if yes contact your supplier before going further unless you know the risks.

Are all the wires intact? Many times you can see a loose wire...and that is probably the culprit. Track all the wires that you can, the best that you can and make sure they are soldered into place.

All our BMS's have a white connector that plug into the board on the BMS (called sense wires or balance wires). Sometimes this plug can wiggle loose. Make sure it is plugged in firmly.
If none of this resurrects your pack its time for some real fun.

3.1 First step and really important one.... Do a hard reset on the BMS!

Unplug that large white balance connector¦. Wait a minute and then plug it back in. This sometimes will reset a BMS that jump starting has failed on. leave the pack open and test charging it again... if it now charges, put it back together and do a discharge and charge again.
.

3.2 If that didn't work so now it's time to test the BMS....by checking all your cell banks using a volt meter on the Balance connector

If your voltages are pretty normal (slight unbalance is possible) you probably need to change the BMS!!! Contact your supplier to get a new one or get one online!

Note: If you have a big unbalance, no voltage on one cell or more, contact your supplier for further info, it could be the BMS or it could be a bad cell in a parallel bank.
Any time you see an imbalance it is a good idea to closely inspect the cells again and look for any physical damage that may be apparent.

3.3 If you have bad cell banks or bad BMS

This is very bad news and is a rare occurrence. This happens usually from dropping the pack and damaging a cell or the spot welds that hold the cells together.

Many times it is caused by a bad BMS that takes down a row or two of cells with it.

Trying to fix a pack with bad rows of cells is for advanced users only, and if you bought your pack from Luna Cycle now is a good time to consider having them do the repair.

If the cell bank in question is not too low you can try to resurrect it using a low voltage charger and get it up to the level of the rest of the banks. You would also want to replace the BMS because now the BMS is suspect.

If the cell bank is very low (under 2.5 volts) this bank can never be safely resurrected and you should not even try.

If you have bad cell banks that cannot be saved it is a good time to give up on the pack....or go through the nightmare job of disassembling the pack and trying to salvage the good cells or replace the bad cells using a spot welder.

Replacing your Bad BMS

The BMS is not very hard to replace if you can get the same exact BMS your pack was constructed with so the Balance connector matches up.
You can get a matching replacement BMS very easily for a Luna Cycle pack if you bought your pack from us.

Here is a good article on replacing a BMS.

**paxtana** · 02-25-2017, 03:42 PM

Miscellaneous issues and questions

How to bypass the battery to see if system runs from alternate power source?

This video shows how to bypass the battery completely by running the system off of the charger. Note you probably do need an xt60 output on the charger to adequately wire it up, and it may spark a little bit when adding the wiring. Try to wedge the wiring into the fins of the contact on the xt connector(s) so it stays put while testing. May not work with all chargers depending on if charger needs to see a load to send power but this will work with most ebike chargers. Take care to get the polarity right and use a multimeter to verify if unsure. There is a + and - on XT connectors on the sides you can use to help verify you have polarity right.

How to test polarity on some wiring?

How to load test the battery to see if battery runs when using something other than the kit?

(Take care not to short out anything which might potentially make things worse when using this guide) If you do you will need to reset BMS by charging it if it is a softpack, or jumpstart through discharge contact if it is a hardcase pack.
For a more conclusive load test you would need to build something that will simulate the high power consumption of an ebike, i.e. using multiple lights at once as the load or using multiple resistors as the load. Here is an example of using multiple lights to do a high power load test

How to test for resistance and continuity within your power wiring

How to capacity test your battery

Selector switch for varying charge percentage has stopped working:
typically if this happens it is due to the module that is connected to the selector switch, it is not user repairable.

Broken display on Luna advanced:
Sometimes the plug has just come unplugged on the charger display, you can follow the instructions at the top of this page to try plugging it back in if that does not work swap out the display

Pack does not seem to be balancing:
it is either the BMS or the charger

my Fan does stop/start when it is near 100% charge
this is normal operation and due to the balancing, the charger will turn itself off and on as the BMS drains down the voltage in the battery to the cell with the lowest voltage in order to keep everything balanced, then the charger adds a bit more power to bring the voltage back up,, this is done repeatedly

Not charging to full capacity
Takes 5 charges for a battery to get to full capacity when new and after a long storage.

I only see the voltage at 56.4
it is highly likely that there is nothing wrong with your charger and you are simply reading off of the DPC 14 BBSxx kit display which only shows voltage up to 56.4 but which will show accurate voltage when voltage drops below that level, around 75% charge capacity on a 52 V nominal pack

my charger display shows voltage output at a fraction of a volt less than stated output on the label
it can happen but it's not something to be alarmed about

Charger only works sporadically:
Practically all ebike chargers on the market need to be physically unplugged from both the wall outlet and battery for a minimum 30 seconds before the charger resets to start a new charge cycle. If this is not done the charger may still be stuck in balance charging mode and may not work right.

My charger is working a little too well, can I dial down the voltage?
Yes you can adjust voltage on any metal Luna charger by adjusting the potentiometer inside the charger.

Please click here for fine tuning voltage output on Luna chargers

Jumbo shark and killer whale pack charging issues:
Jumbo: Try this first:
Unplug everything (charger from wall, charger from pack, pack from cradle, and charger adapter if you have one). Give the charger 30 seconds or so before proceeding.
Select the % you want.
Plug the AC male connector on the charger in the wall outlet.
Unplug the battery from the bike, turn off the switch on the battery.
Plug your charging adaptor to the battery (if you have one) if not just plug the charger in the battery
Plug the XT-60 front the charger to the XT-60 of the adaptor. (again if you have a charging adaptor)
Turn the power switch "on" for the charge (important)
Once done unplug the charger and turn the switch off.

If no joy and you have never charged it before, check the pins on charge port. pin 1 supposed to be positive, pin 2 negative, pin 3 unused. You can verify the power is on the correct pins by testing with a multimeter.

Killer Whale:
NOTE: Some killer whale pack needs to be in the "off" position to be able to charge normally, it's due that some have a different BMS.

If you still have issues:

While the charger is connected, if the battery's on/off switch is cycled off then back on, the charger will start to charge. Ideally you just plug charger into the wall outlet then plug charger into pack with the pack switched in the ON position but there was a revision to the design so you may need to cycle the switch first. Also, after the battery is finished charging we recommend putting the switch into the off position or it will slowly drain the battery due to being in standby mode.

How to test charge port on a hardcase battery:

If your pack is not taking a charge but is discharging fine then most of the time the issue is with the XT60 barrel adapter. You can test by using a different adapter and plugging it into the charge port then testing for voltage with a multimeter by putting your multimeter leads into the xt60 (do not do this directly into the charge port). If you see voltage then the charge port is working and the issue is either your previous adapter or the charger.

If you do not see voltage when testing with a new adapter open up the battery and bypass the charge port by testing the wires going to the charge port, pushing your multimeter leads through the insulation. If you now see voltage then the charge port is broken. If you have latest Shark you can simply unplug the xt30 from the other side of this connector and test for power at the xt30.

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Troubleshooting charging and electrical issues

Troubleshooting charging and electrical issues

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