Battery Rebuilding and "Boosting" Demystified
WED, 10/17/2012 - 10:11AM
Click Here for Segway's
Official Statement on
Rebuilt Batteries.
Over the past several years there have been a number of companies that have started offering services for Segway batteries such as "rebuilding" and "boosting", otherwise known as reconditioning. We will begin this article with a discussion on rebuilding Segway batteries.
The Segway lithium ion battery packs are more than just a battery. Aside from their eye popping specs (73.6 Volts, 5.2 Amp hours, 382 Watt Hours) each pack contains a proprietary computer control board that is preloaded with software to allow them to communicate with the machine. As can be seen in the picture this is a far cry from the typical AA batteries we throw in our TV remotes! The problem with batteries this complicated is they inherently have a lot of opportunities for something to go bad in them. Since the Segway PT's are very picky as to what they deem as acceptable battery performance, there may not be much wrong with the battery before the machine rejects it for preprogrammed safety reasons. That is where some of the battery rebuilding companies come into the picture.
The way these rebuilds work is they determine first whether a battery is salvageable by running a diagnostics. once they have verified this they then cut open the non-serviceable battery packs, remove the components, replace the damaged cells, and then seal them back together. like any other type of repair of this nature the second finished product is never going to be as good as the first, or in many cases up to the acceptable standards as the first. there is no guarantee that the environment these repairs are being done in is going to have proper particle or moisture control, something critical when dealing with a sealed battery full of computer boards. Also there is no guarantee the replacement cells will operate properly with the existing ones as they could either be from a different company or simply not work well with the others because of their age difference. I have had customers who have gone the rebuild route which h I will discuss in closing, however, let’s take a look at the latest phase in battery repair known as boosting.
the Segway PT's are extremely picky about what they will accept before operating. Many people write this off as them being glitchy but in reality they are purposefully designed this way so that anything the electronics deem to be out of their strict preprogrammed parameters as "dangerous" makes them shut down. The reality of it is that we live in a sue happy world and they were designed this way mitigate liability, but that’s a whole other story. So how does this relate to boosting, or reconditioning?
when Segway’s are left off of chargers for long periods of time or kept in environments that are outside the batteries temperature parameters (>122F or <-4F) cells can become discharged to the point that the machine won’t recognize them. Once the voltage floor threshold has been breached the units are designed not to recharge these cells as there is a good chance they could have been damaged from over discharging. Likewise the result is a battery that the machine will reject as
recharging these damaged cells will lead to a failure in the future. What companies that recondition batteries do is essentially boost the (possibly) damaged cells to an acceptable voltage level for the machines and allow them to recognize them again. How long they will last is anyone’s guess depending on a number of factors, mainly age of the cells. Boosting, in my opinion, is a game of pocketbook roulette. You could enjoy years of use if say your batteries were very new, discharged just below the threshold, then boosted. On the other hand you could have a set that was a couple of years old, extensively discharged and brought back to life only to die again. It’s the human equivalent of jumpstarting a heart with a defibrillator, a twenty year old heart would have better odds than say an 80 year old heart!
So now that everything is clear as mud what is my humble opinion on the issue? Personally I think the rebuilds are a reckless way to save money in the short run. The batteries I have seen that have been rebuilt look sloppily put back together (look like a hack saw and RTV sealer were used in the process) and the one customer that brought a machine in with them was getting an error code that said the batteries were overheating. I have never seen this on a Segway battery operating in room temperature probably because their cells are specifically designed to eliminate thermal runaway. Throw an odd cell in the mix that is not specifically engineered to function this way and this is what you get. Also use of these batteries voids any and all warranties to all internal components down to the wiring harness. The companies that do the rebuilds claim they use the "improved" cells from Segway's supplier, Valence, yet get another .8 Amp hours thus extending the range. This doesn’t really sound like a restoration to factory standards. Considering what we know about the machines picky nature I roll my eyes when reading these claims. Apparently Segway, which spent around $100 million dollars developing their product, has been outdone by a company that offers repair services.
When it comes to boosting I see this as less of an issue as the integrity of the battery is has not been compromised to the extent of rebuilding. The problem with this, however, is that this application may be used when it shouldn’t. As mentioned earlier if you had a new set of batteries that was used for a few months, then sat over the winter, and then wouldn’t start your shot at those new cells being revived might be pretty good. On the other hand if you have batteries that are several years old, may already be weakened by age and are further weakened by over discharging, the chances that one of the dozens of cells in the pack is damaged is pretty good. This service, like rebuilding, also voids any and all warranties to the Segway's electrical components.
After looking at all the facts I think it is safe to say that in most cases the best route to go would be purchasing new batteries. Many may see this whole write up as a well cloaked sales pitch, however, I think there are legitimate concerns with using products that are not built to factory standards on a very sensitive (and expensive) electronic machine. I always tell people it’s like anything else in life, you either pay now or you pay later but in the end you pay! If rebuilds were the route to go we, as a dealer with rentals in the past, would not have dumped literally over 100 batteries off at the local recycling venue for $3 a piece. It all depends on how much risk you are comfortable with in order to save a few hundred dollars (yes its that little, for a set, after shipping/warranty fees are applied). If you have had experience with rebuilds in the past we would like to hear from you, good and bad, and do another write up in the future